* SQLiteDatabase has methods to create, delete, execute SQL commands, and * perform other common database management tasks. *
* See the Notepad sample application in the SDK for an example of creating * and managing a database. *
* Database names must be unique within an application, not across all applications. *
* *
* In addition to SQLite's default BINARY collator, Android supplies
* two more, LOCALIZED, which changes with the system's current locale,
* and UNICODE, which is the Unicode Collation Algorithm and not tailored
* to the current locale.
*
LOCALIZED not to be created.
* You must be consistent when using this flag to use the setting the database was
* created with. If this is set, {@link #setLocale} will do nothing.
*/
public static final int NO_LOCALIZED_COLLATORS = 0x00000010; // update native code if changing
/**
* Open flag: Flag for {@link #openDatabase} to create the database file if it does not
* already exist.
*/
public static final int CREATE_IF_NECESSARY = 0x10000000; // update native code if changing
/**
* Open flag: Flag for {@link #openDatabase} to open the database file with
* write-ahead logging enabled by default. Using this flag is more efficient
* than calling {@link #enableWriteAheadLogging}.
*
* Write-ahead logging cannot be used with read-only databases so the value of
* this flag is ignored if the database is opened read-only.
*
* @see #enableWriteAheadLogging
*/
public static final int ENABLE_WRITE_AHEAD_LOGGING = 0x20000000;
/**
* Absolute max value that can be set by {@link #setMaxSqlCacheSize(int)}.
*
* Each prepared-statement is between 1K - 6K, depending on the complexity of the
* SQL statement & schema. A large SQL cache may use a significant amount of memory.
*/
public static final int MAX_SQL_CACHE_SIZE = 100;
private SQLiteDatabase(String path, int openFlags, CursorFactory cursorFactory,
DatabaseErrorHandler errorHandler) {
mCursorFactory = cursorFactory;
mErrorHandler = errorHandler != null ? errorHandler : new DefaultDatabaseErrorHandler();
mConfigurationLocked = new SQLiteDatabaseConfiguration(path, openFlags);
}
@Override
protected void finalize() throws Throwable {
try {
dispose(true);
} finally {
super.finalize();
}
}
@Override
protected void onAllReferencesReleased() {
dispose(false);
}
private void dispose(boolean finalized) {
final SQLiteConnectionPool pool;
synchronized (mLock) {
if (mCloseGuardLocked != null) {
if (finalized) {
mCloseGuardLocked.warnIfOpen();
}
mCloseGuardLocked.close();
}
pool = mConnectionPoolLocked;
mConnectionPoolLocked = null;
}
if (!finalized) {
synchronized (sActiveDatabases) {
sActiveDatabases.remove(this);
}
if (pool != null) {
pool.close();
}
}
}
/**
* Attempts to release memory that SQLite holds but does not require to
* operate properly. Typically this memory will come from the page cache.
*
* @return the number of bytes actually released
*/
public static int releaseMemory() {
return SQLiteGlobal.releaseMemory();
}
/**
* Control whether or not the SQLiteDatabase is made thread-safe by using locks
* around critical sections. This is pretty expensive, so if you know that your
* DB will only be used by a single thread then you should set this to false.
* The default is true.
* @param lockingEnabled set to true to enable locks, false otherwise
*
* @deprecated This method now does nothing. Do not use.
*/
@Deprecated
public void setLockingEnabled(boolean lockingEnabled) {
}
/**
* Gets a label to use when describing the database in log messages.
* @return The label.
*/
String getLabel() {
synchronized (mLock) {
return mConfigurationLocked.label;
}
}
/**
* Sends a corruption message to the database error handler.
*/
void onCorruption() {
EventLog.writeEvent(EVENT_DB_CORRUPT, getLabel());
mErrorHandler.onCorruption(this);
}
/**
* Gets the {@link SQLiteSession} that belongs to this thread for this database.
* Once a thread has obtained a session, it will continue to obtain the same
* session even after the database has been closed (although the session will not
* be usable). However, a thread that does not already have a session cannot
* obtain one after the database has been closed.
*
* The idea is that threads that have active connections to the database may still
* have work to complete even after the call to {@link #close}. Active database
* connections are not actually disposed until they are released by the threads
* that own them.
*
* @return The session, never null.
*
* @throws IllegalStateException if the thread does not yet have a session and
* the database is not open.
*/
SQLiteSession getThreadSession() {
return mThreadSession.get(); // initialValue() throws if database closed
}
SQLiteSession createSession() {
final SQLiteConnectionPool pool;
synchronized (mLock) {
throwIfNotOpenLocked();
pool = mConnectionPoolLocked;
}
return new SQLiteSession(pool);
}
/**
* Gets default connection flags that are appropriate for this thread, taking into
* account whether the thread is acting on behalf of the UI.
*
* @param readOnly True if the connection should be read-only.
* @return The connection flags.
*/
int getThreadDefaultConnectionFlags(boolean readOnly) {
int flags = readOnly ? SQLiteConnectionPool.CONNECTION_FLAG_READ_ONLY :
SQLiteConnectionPool.CONNECTION_FLAG_PRIMARY_CONNECTION_AFFINITY;
if (isMainThread()) {
flags |= SQLiteConnectionPool.CONNECTION_FLAG_INTERACTIVE;
}
return flags;
}
private static boolean isMainThread() {
// FIXME: There should be a better way to do this.
// Would also be nice to have something that would work across Binder calls.
Looper looper = Looper.myLooper();
return looper != null && looper == Looper.getMainLooper();
}
/**
* Begins a transaction in EXCLUSIVE mode.
* * Transactions can be nested. * When the outer transaction is ended all of * the work done in that transaction and all of the nested transactions will be committed or * rolled back. The changes will be rolled back if any transaction is ended without being * marked as clean (by calling setTransactionSuccessful). Otherwise they will be committed. *
*Here is the standard idiom for transactions: * *
* db.beginTransaction();
* try {
* ...
* db.setTransactionSuccessful();
* } finally {
* db.endTransaction();
* }
*
*/
public void beginTransaction() {
beginTransaction(null /* transactionStatusCallback */, true);
}
/**
* Begins a transaction in IMMEDIATE mode. Transactions can be nested. When
* the outer transaction is ended all of the work done in that transaction
* and all of the nested transactions will be committed or rolled back. The
* changes will be rolled back if any transaction is ended without being
* marked as clean (by calling setTransactionSuccessful). Otherwise they
* will be committed.
* * Here is the standard idiom for transactions: * *
* db.beginTransactionNonExclusive();
* try {
* ...
* db.setTransactionSuccessful();
* } finally {
* db.endTransaction();
* }
*
*/
public void beginTransactionNonExclusive() {
beginTransaction(null /* transactionStatusCallback */, false);
}
/**
* Begins a transaction in EXCLUSIVE mode.
* * Transactions can be nested. * When the outer transaction is ended all of * the work done in that transaction and all of the nested transactions will be committed or * rolled back. The changes will be rolled back if any transaction is ended without being * marked as clean (by calling setTransactionSuccessful). Otherwise they will be committed. *
*Here is the standard idiom for transactions: * *
* db.beginTransactionWithListener(listener);
* try {
* ...
* db.setTransactionSuccessful();
* } finally {
* db.endTransaction();
* }
*
*
* @param transactionListener listener that should be notified when the transaction begins,
* commits, or is rolled back, either explicitly or by a call to
* {@link #yieldIfContendedSafely}.
*/
public void beginTransactionWithListener(SQLiteTransactionListener transactionListener) {
beginTransaction(transactionListener, true);
}
/**
* Begins a transaction in IMMEDIATE mode. Transactions can be nested. When
* the outer transaction is ended all of the work done in that transaction
* and all of the nested transactions will be committed or rolled back. The
* changes will be rolled back if any transaction is ended without being
* marked as clean (by calling setTransactionSuccessful). Otherwise they
* will be committed.
* * Here is the standard idiom for transactions: * *
* db.beginTransactionWithListenerNonExclusive(listener);
* try {
* ...
* db.setTransactionSuccessful();
* } finally {
* db.endTransaction();
* }
*
*
* @param transactionListener listener that should be notified when the
* transaction begins, commits, or is rolled back, either
* explicitly or by a call to {@link #yieldIfContendedSafely}.
*/
public void beginTransactionWithListenerNonExclusive(
SQLiteTransactionListener transactionListener) {
beginTransaction(transactionListener, false);
}
private void beginTransaction(SQLiteTransactionListener transactionListener,
boolean exclusive) {
acquireReference();
try {
getThreadSession().beginTransaction(
exclusive ? SQLiteSession.TRANSACTION_MODE_EXCLUSIVE :
SQLiteSession.TRANSACTION_MODE_IMMEDIATE,
transactionListener,
getThreadDefaultConnectionFlags(false /*readOnly*/), null);
} finally {
releaseReference();
}
}
/**
* End a transaction. See beginTransaction for notes about how to use this and when transactions
* are committed and rolled back.
*/
public void endTransaction() {
acquireReference();
try {
getThreadSession().endTransaction(null);
} finally {
releaseReference();
}
}
/**
* Marks the current transaction as successful. Do not do any more database work between
* calling this and calling endTransaction. Do as little non-database work as possible in that
* situation too. If any errors are encountered between this and endTransaction the transaction
* will still be committed.
*
* @throws IllegalStateException if the current thread is not in a transaction or the
* transaction is already marked as successful.
*/
public void setTransactionSuccessful() {
acquireReference();
try {
getThreadSession().setTransactionSuccessful();
} finally {
releaseReference();
}
}
/**
* Returns true if the current thread has a transaction pending.
*
* @return True if the current thread is in a transaction.
*/
public boolean inTransaction() {
acquireReference();
try {
return getThreadSession().hasTransaction();
} finally {
releaseReference();
}
}
/**
* Returns true if the current thread is holding an active connection to the database.
* * The name of this method comes from a time when having an active connection * to the database meant that the thread was holding an actual lock on the * database. Nowadays, there is no longer a true "database lock" although threads * may block if they cannot acquire a database connection to perform a * particular operation. *
* * @return True if the current thread is holding an active connection to the database. */ public boolean isDbLockedByCurrentThread() { acquireReference(); try { return getThreadSession().hasConnection(); } finally { releaseReference(); } } /** * Always returns false. ** There is no longer the concept of a database lock, so this method always returns false. *
* * @return False. * @deprecated Always returns false. Do not use this method. */ @Deprecated public boolean isDbLockedByOtherThreads() { return false; } /** * Temporarily end the transaction to let other threads run. The transaction is assumed to be * successful so far. Do not call setTransactionSuccessful before calling this. When this * returns a new transaction will have been created but not marked as successful. * @return true if the transaction was yielded * @deprecated if the db is locked more than once (becuase of nested transactions) then the lock * will not be yielded. Use yieldIfContendedSafely instead. */ @Deprecated public boolean yieldIfContended() { return yieldIfContendedHelper(false /* do not check yielding */, -1 /* sleepAfterYieldDelay */); } /** * Temporarily end the transaction to let other threads run. The transaction is assumed to be * successful so far. Do not call setTransactionSuccessful before calling this. When this * returns a new transaction will have been created but not marked as successful. This assumes * that there are no nested transactions (beginTransaction has only been called once) and will * throw an exception if that is not the case. * @return true if the transaction was yielded */ public boolean yieldIfContendedSafely() { return yieldIfContendedHelper(true /* check yielding */, -1 /* sleepAfterYieldDelay*/); } /** * Temporarily end the transaction to let other threads run. The transaction is assumed to be * successful so far. Do not call setTransactionSuccessful before calling this. When this * returns a new transaction will have been created but not marked as successful. This assumes * that there are no nested transactions (beginTransaction has only been called once) and will * throw an exception if that is not the case. * @param sleepAfterYieldDelay if > 0, sleep this long before starting a new transaction if * the lock was actually yielded. This will allow other background threads to make some * more progress than they would if we started the transaction immediately. * @return true if the transaction was yielded */ public boolean yieldIfContendedSafely(long sleepAfterYieldDelay) { return yieldIfContendedHelper(true /* check yielding */, sleepAfterYieldDelay); } private boolean yieldIfContendedHelper(boolean throwIfUnsafe, long sleepAfterYieldDelay) { acquireReference(); try { return getThreadSession().yieldTransaction(sleepAfterYieldDelay, throwIfUnsafe, null); } finally { releaseReference(); } } /** * Deprecated. * @deprecated This method no longer serves any useful purpose and has been deprecated. */ @Deprecated public MapSets the locale of the database to the the system's current locale. * Call {@link #setLocale} if you would like something else.
* * @param path to database file to open and/or create * @param factory an optional factory class that is called to instantiate a * cursor when query is called, or null for default * @param flags to control database access mode * @return the newly opened database * @throws SQLiteException if the database cannot be opened */ public static SQLiteDatabase openDatabase(String path, CursorFactory factory, int flags) { return openDatabase(path, factory, flags, null); } /** * Open the database according to the flags {@link #OPEN_READWRITE} * {@link #OPEN_READONLY} {@link #CREATE_IF_NECESSARY} and/or {@link #NO_LOCALIZED_COLLATORS}. * *Sets the locale of the database to the the system's current locale. * Call {@link #setLocale} if you would like something else.
* *Accepts input param: a concrete instance of {@link DatabaseErrorHandler} to be * used to handle corruption when sqlite reports database corruption.
* * @param path to database file to open and/or create * @param factory an optional factory class that is called to instantiate a * cursor when query is called, or null for default * @param flags to control database access mode * @param errorHandler the {@link DatabaseErrorHandler} obj to be used to handle corruption * when sqlite reports database corruption * @return the newly opened database * @throws SQLiteException if the database cannot be opened */ public static SQLiteDatabase openDatabase(String path, CursorFactory factory, int flags, DatabaseErrorHandler errorHandler) { SQLiteDatabase db = new SQLiteDatabase(path, flags, factory, errorHandler); db.open(); return db; } /** * Equivalent to openDatabase(file.getPath(), factory, CREATE_IF_NECESSARY). */ public static SQLiteDatabase openOrCreateDatabase(File file, CursorFactory factory) { return openOrCreateDatabase(file.getPath(), factory); } /** * Equivalent to openDatabase(path, factory, CREATE_IF_NECESSARY). */ public static SQLiteDatabase openOrCreateDatabase(String path, CursorFactory factory) { return openDatabase(path, factory, CREATE_IF_NECESSARY, null); } /** * Equivalent to openDatabase(path, factory, CREATE_IF_NECESSARY, errorHandler). */ public static SQLiteDatabase openOrCreateDatabase(String path, CursorFactory factory, DatabaseErrorHandler errorHandler) { return openDatabase(path, factory, CREATE_IF_NECESSARY, errorHandler); } /** * Deletes a database including its journal file and other auxiliary files * that may have been created by the database engine. * * @param file The database file path. * @return True if the database was successfully deleted. */ public static boolean deleteDatabase(File file) { if (file == null) { throw new IllegalArgumentException("file must not be null"); } boolean deleted = false; deleted |= file.delete(); deleted |= new File(file.getPath() + "-journal").delete(); deleted |= new File(file.getPath() + "-shm").delete(); deleted |= new File(file.getPath() + "-wal").delete(); File dir = file.getParentFile(); if (dir != null) { final String prefix = file.getName() + "-mj"; final FileFilter filter = new FileFilter() { @Override public boolean accept(File candidate) { return candidate.getName().startsWith(prefix); } }; for (File masterJournal : dir.listFiles(filter)) { deleted |= masterJournal.delete(); } } return deleted; } /** * Reopens the database in read-write mode. * If the database is already read-write, does nothing. * * @throws SQLiteException if the database could not be reopened as requested, in which * case it remains open in read only mode. * @throws IllegalStateException if the database is not open. * * @see #isReadOnly() * @hide */ public void reopenReadWrite() { synchronized (mLock) { throwIfNotOpenLocked(); if (!isReadOnlyLocked()) { return; // nothing to do } // Reopen the database in read-write mode. final int oldOpenFlags = mConfigurationLocked.openFlags; mConfigurationLocked.openFlags = (mConfigurationLocked.openFlags & ~OPEN_READ_MASK) | OPEN_READWRITE; try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.openFlags = oldOpenFlags; throw ex; } } } private void open() { try { try { openInner(); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); openInner(); } } catch (SQLiteException ex) { Log.e(TAG, "Failed to open database '" + getLabel() + "'.", ex); close(); throw ex; } } private void openInner() { synchronized (mLock) { assert mConnectionPoolLocked == null; mConnectionPoolLocked = SQLiteConnectionPool.open(mConfigurationLocked); mCloseGuardLocked.open("close"); } synchronized (sActiveDatabases) { sActiveDatabases.put(this, null); } } /** * Create a memory backed SQLite database. Its contents will be destroyed * when the database is closed. * *Sets the locale of the database to the the system's current locale. * Call {@link #setLocale} if you would like something else.
* * @param factory an optional factory class that is called to instantiate a * cursor when query is called * @return a SQLiteDatabase object, or null if the database can't be created */ public static SQLiteDatabase create(CursorFactory factory) { // This is a magic string with special meaning for SQLite. return openDatabase(SQLiteDatabaseConfiguration.MEMORY_DB_PATH, factory, CREATE_IF_NECESSARY); } /** * Registers a CustomFunction callback as a function that can be called from * SQLite database triggers. * * @param name the name of the sqlite3 function * @param numArgs the number of arguments for the function * @param function callback to call when the function is executed * @hide */ public void addCustomFunction(String name, int numArgs, CustomFunction function) { // Create wrapper (also validates arguments). SQLiteCustomFunction wrapper = new SQLiteCustomFunction(name, numArgs, function); synchronized (mLock) { throwIfNotOpenLocked(); mConfigurationLocked.customFunctions.add(wrapper); try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.customFunctions.remove(wrapper); throw ex; } } } /** * Gets the database version. * * @return the database version */ public int getVersion() { return ((Long) DatabaseUtils.longForQuery(this, "PRAGMA user_version;", null)).intValue(); } /** * Sets the database version. * * @param version the new database version */ public void setVersion(int version) { execSQL("PRAGMA user_version = " + version); } /** * Returns the maximum size the database may grow to. * * @return the new maximum database size */ public long getMaximumSize() { long pageCount = DatabaseUtils.longForQuery(this, "PRAGMA max_page_count;", null); return pageCount * getPageSize(); } /** * Sets the maximum size the database will grow to. The maximum size cannot * be set below the current size. * * @param numBytes the maximum database size, in bytes * @return the new maximum database size */ public long setMaximumSize(long numBytes) { long pageSize = getPageSize(); long numPages = numBytes / pageSize; // If numBytes isn't a multiple of pageSize, bump up a page if ((numBytes % pageSize) != 0) { numPages++; } long newPageCount = DatabaseUtils.longForQuery(this, "PRAGMA max_page_count = " + numPages, null); return newPageCount * pageSize; } /** * Returns the current database page size, in bytes. * * @return the database page size, in bytes */ public long getPageSize() { return DatabaseUtils.longForQuery(this, "PRAGMA page_size;", null); } /** * Sets the database page size. The page size must be a power of two. This * method does not work if any data has been written to the database file, * and must be called right after the database has been created. * * @param numBytes the database page size, in bytes */ public void setPageSize(long numBytes) { execSQL("PRAGMA page_size = " + numBytes); } /** * Mark this table as syncable. When an update occurs in this table the * _sync_dirty field will be set to ensure proper syncing operation. * * @param table the table to mark as syncable * @param deletedTable The deleted table that corresponds to the * syncable table * @deprecated This method no longer serves any useful purpose and has been deprecated. */ @Deprecated public void markTableSyncable(String table, String deletedTable) { } /** * Mark this table as syncable, with the _sync_dirty residing in another * table. When an update occurs in this table the _sync_dirty field of the * row in updateTable with the _id in foreignKey will be set to * ensure proper syncing operation. * * @param table an update on this table will trigger a sync time removal * @param foreignKey this is the column in table whose value is an _id in * updateTable * @param updateTable this is the table that will have its _sync_dirty * @deprecated This method no longer serves any useful purpose and has been deprecated. */ @Deprecated public void markTableSyncable(String table, String foreignKey, String updateTable) { } /** * Finds the name of the first table, which is editable. * * @param tables a list of tables * @return the first table listed */ public static String findEditTable(String tables) { if (!TextUtils.isEmpty(tables)) { // find the first word terminated by either a space or a comma int spacepos = tables.indexOf(' '); int commapos = tables.indexOf(','); if (spacepos > 0 && (spacepos < commapos || commapos < 0)) { return tables.substring(0, spacepos); } else if (commapos > 0 && (commapos < spacepos || spacepos < 0) ) { return tables.substring(0, commapos); } return tables; } else { throw new IllegalStateException("Invalid tables"); } } /** * Compiles an SQL statement into a reusable pre-compiled statement object. * The parameters are identical to {@link #execSQL(String)}. You may put ?s in the * statement and fill in those values with {@link SQLiteProgram#bindString} * and {@link SQLiteProgram#bindLong} each time you want to run the * statement. Statements may not return result sets larger than 1x1. *
* No two threads should be using the same {@link SQLiteStatement} at the same time.
*
* @param sql The raw SQL statement, may contain ? for unknown values to be
* bound later.
* @return A pre-compiled {@link SQLiteStatement} object. Note that
* {@link SQLiteStatement}s are not synchronized, see the documentation for more details.
*/
public SQLiteStatement compileStatement(String sql) throws SQLException {
acquireReference();
try {
return new SQLiteStatement(this, sql, null);
} finally {
releaseReference();
}
}
/**
* Query the given URL, returning a {@link Cursor} over the result set.
*
* @param distinct true if you want each row to be unique, false otherwise.
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor query(boolean distinct, String table, String[] columns,
String selection, String[] selectionArgs, String groupBy,
String having, String orderBy, String limit) {
return queryWithFactory(null, distinct, table, columns, selection, selectionArgs,
groupBy, having, orderBy, limit, null);
}
/**
* Query the given URL, returning a {@link Cursor} over the result set.
*
* @param distinct true if you want each row to be unique, false otherwise.
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* If the operation is canceled, then {@link OperationCanceledException} will be thrown
* when the query is executed.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor query(boolean distinct, String table, String[] columns,
String selection, String[] selectionArgs, String groupBy,
String having, String orderBy, String limit, CancellationSignal cancellationSignal) {
return queryWithFactory(null, distinct, table, columns, selection, selectionArgs,
groupBy, having, orderBy, limit, cancellationSignal);
}
/**
* Query the given URL, returning a {@link Cursor} over the result set.
*
* @param cursorFactory the cursor factory to use, or null for the default factory
* @param distinct true if you want each row to be unique, false otherwise.
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor queryWithFactory(CursorFactory cursorFactory,
boolean distinct, String table, String[] columns,
String selection, String[] selectionArgs, String groupBy,
String having, String orderBy, String limit) {
return queryWithFactory(cursorFactory, distinct, table, columns, selection,
selectionArgs, groupBy, having, orderBy, limit, null);
}
/**
* Query the given URL, returning a {@link Cursor} over the result set.
*
* @param cursorFactory the cursor factory to use, or null for the default factory
* @param distinct true if you want each row to be unique, false otherwise.
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* If the operation is canceled, then {@link OperationCanceledException} will be thrown
* when the query is executed.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor queryWithFactory(CursorFactory cursorFactory,
boolean distinct, String table, String[] columns,
String selection, String[] selectionArgs, String groupBy,
String having, String orderBy, String limit, CancellationSignal cancellationSignal) {
acquireReference();
try {
String sql = SQLiteQueryBuilder.buildQueryString(
distinct, table, columns, selection, groupBy, having, orderBy, limit);
return rawQueryWithFactory(cursorFactory, sql, selectionArgs,
findEditTable(table), cancellationSignal);
} finally {
releaseReference();
}
}
/**
* Query the given table, returning a {@link Cursor} over the result set.
*
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor query(String table, String[] columns, String selection,
String[] selectionArgs, String groupBy, String having,
String orderBy) {
return query(false, table, columns, selection, selectionArgs, groupBy,
having, orderBy, null /* limit */);
}
/**
* Query the given table, returning a {@link Cursor} over the result set.
*
* @param table The table name to compile the query against.
* @param columns A list of which columns to return. Passing null will
* return all columns, which is discouraged to prevent reading
* data from storage that isn't going to be used.
* @param selection A filter declaring which rows to return, formatted as an
* SQL WHERE clause (excluding the WHERE itself). Passing null
* will return all rows for the given table.
* @param selectionArgs You may include ?s in selection, which will be
* replaced by the values from selectionArgs, in order that they
* appear in the selection. The values will be bound as Strings.
* @param groupBy A filter declaring how to group rows, formatted as an SQL
* GROUP BY clause (excluding the GROUP BY itself). Passing null
* will cause the rows to not be grouped.
* @param having A filter declare which row groups to include in the cursor,
* if row grouping is being used, formatted as an SQL HAVING
* clause (excluding the HAVING itself). Passing null will cause
* all row groups to be included, and is required when row
* grouping is not being used.
* @param orderBy How to order the rows, formatted as an SQL ORDER BY clause
* (excluding the ORDER BY itself). Passing null will use the
* default sort order, which may be unordered.
* @param limit Limits the number of rows returned by the query,
* formatted as LIMIT clause. Passing null denotes no LIMIT clause.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
* @see Cursor
*/
public Cursor query(String table, String[] columns, String selection,
String[] selectionArgs, String groupBy, String having,
String orderBy, String limit) {
return query(false, table, columns, selection, selectionArgs, groupBy,
having, orderBy, limit);
}
/**
* Runs the provided SQL and returns a {@link Cursor} over the result set.
*
* @param sql the SQL query. The SQL string must not be ; terminated
* @param selectionArgs You may include ?s in where clause in the query,
* which will be replaced by the values from selectionArgs. The
* values will be bound as Strings.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
*/
public Cursor rawQuery(String sql, String[] selectionArgs) {
return rawQueryWithFactory(null, sql, selectionArgs, null, null);
}
/**
* Runs the provided SQL and returns a {@link Cursor} over the result set.
*
* @param sql the SQL query. The SQL string must not be ; terminated
* @param selectionArgs You may include ?s in where clause in the query,
* which will be replaced by the values from selectionArgs. The
* values will be bound as Strings.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* If the operation is canceled, then {@link OperationCanceledException} will be thrown
* when the query is executed.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
*/
public Cursor rawQuery(String sql, String[] selectionArgs,
CancellationSignal cancellationSignal) {
return rawQueryWithFactory(null, sql, selectionArgs, null, cancellationSignal);
}
/**
* Runs the provided SQL and returns a cursor over the result set.
*
* @param cursorFactory the cursor factory to use, or null for the default factory
* @param sql the SQL query. The SQL string must not be ; terminated
* @param selectionArgs You may include ?s in where clause in the query,
* which will be replaced by the values from selectionArgs. The
* values will be bound as Strings.
* @param editTable the name of the first table, which is editable
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
*/
public Cursor rawQueryWithFactory(
CursorFactory cursorFactory, String sql, String[] selectionArgs,
String editTable) {
return rawQueryWithFactory(cursorFactory, sql, selectionArgs, editTable, null);
}
/**
* Runs the provided SQL and returns a cursor over the result set.
*
* @param cursorFactory the cursor factory to use, or null for the default factory
* @param sql the SQL query. The SQL string must not be ; terminated
* @param selectionArgs You may include ?s in where clause in the query,
* which will be replaced by the values from selectionArgs. The
* values will be bound as Strings.
* @param editTable the name of the first table, which is editable
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* If the operation is canceled, then {@link OperationCanceledException} will be thrown
* when the query is executed.
* @return A {@link Cursor} object, which is positioned before the first entry. Note that
* {@link Cursor}s are not synchronized, see the documentation for more details.
*/
public Cursor rawQueryWithFactory(
CursorFactory cursorFactory, String sql, String[] selectionArgs,
String editTable, CancellationSignal cancellationSignal) {
acquireReference();
try {
SQLiteCursorDriver driver = new SQLiteDirectCursorDriver(this, sql, editTable,
cancellationSignal);
return driver.query(cursorFactory != null ? cursorFactory : mCursorFactory,
selectionArgs);
} finally {
releaseReference();
}
}
/**
* Convenience method for inserting a row into the database.
*
* @param table the table to insert the row into
* @param nullColumnHack optional; may be null.
* SQL doesn't allow inserting a completely empty row without
* naming at least one column name. If your provided values is
* empty, no column names are known and an empty row can't be inserted.
* If not set to null, the nullColumnHack parameter
* provides the name of nullable column name to explicitly insert a NULL into
* in the case where your values is empty.
* @param values this map contains the initial column values for the
* row. The keys should be the column names and the values the
* column values
* @return the row ID of the newly inserted row, or -1 if an error occurred
*/
public long insert(String table, String nullColumnHack, ContentValues values) {
try {
return insertWithOnConflict(table, nullColumnHack, values, CONFLICT_NONE);
} catch (SQLException e) {
Log.e(TAG, "Error inserting " + values, e);
return -1;
}
}
/**
* Convenience method for inserting a row into the database.
*
* @param table the table to insert the row into
* @param nullColumnHack optional; may be null.
* SQL doesn't allow inserting a completely empty row without
* naming at least one column name. If your provided values is
* empty, no column names are known and an empty row can't be inserted.
* If not set to null, the nullColumnHack parameter
* provides the name of nullable column name to explicitly insert a NULL into
* in the case where your values is empty.
* @param values this map contains the initial column values for the
* row. The keys should be the column names and the values the
* column values
* @throws SQLException
* @return the row ID of the newly inserted row, or -1 if an error occurred
*/
public long insertOrThrow(String table, String nullColumnHack, ContentValues values)
throws SQLException {
return insertWithOnConflict(table, nullColumnHack, values, CONFLICT_NONE);
}
/**
* Convenience method for replacing a row in the database.
*
* @param table the table in which to replace the row
* @param nullColumnHack optional; may be null.
* SQL doesn't allow inserting a completely empty row without
* naming at least one column name. If your provided initialValues is
* empty, no column names are known and an empty row can't be inserted.
* If not set to null, the nullColumnHack parameter
* provides the name of nullable column name to explicitly insert a NULL into
* in the case where your initialValues is empty.
* @param initialValues this map contains the initial column values for
* the row.
* @return the row ID of the newly inserted row, or -1 if an error occurred
*/
public long replace(String table, String nullColumnHack, ContentValues initialValues) {
try {
return insertWithOnConflict(table, nullColumnHack, initialValues,
CONFLICT_REPLACE);
} catch (SQLException e) {
Log.e(TAG, "Error inserting " + initialValues, e);
return -1;
}
}
/**
* Convenience method for replacing a row in the database.
*
* @param table the table in which to replace the row
* @param nullColumnHack optional; may be null.
* SQL doesn't allow inserting a completely empty row without
* naming at least one column name. If your provided initialValues is
* empty, no column names are known and an empty row can't be inserted.
* If not set to null, the nullColumnHack parameter
* provides the name of nullable column name to explicitly insert a NULL into
* in the case where your initialValues is empty.
* @param initialValues this map contains the initial column values for
* the row. The key
* @throws SQLException
* @return the row ID of the newly inserted row, or -1 if an error occurred
*/
public long replaceOrThrow(String table, String nullColumnHack,
ContentValues initialValues) throws SQLException {
return insertWithOnConflict(table, nullColumnHack, initialValues,
CONFLICT_REPLACE);
}
/**
* General method for inserting a row into the database.
*
* @param table the table to insert the row into
* @param nullColumnHack optional; may be null.
* SQL doesn't allow inserting a completely empty row without
* naming at least one column name. If your provided initialValues is
* empty, no column names are known and an empty row can't be inserted.
* If not set to null, the nullColumnHack parameter
* provides the name of nullable column name to explicitly insert a NULL into
* in the case where your initialValues is empty.
* @param initialValues this map contains the initial column values for the
* row. The keys should be the column names and the values the
* column values
* @param conflictAlgorithm for insert conflict resolver
* @return the row ID of the newly inserted row
* OR the primary key of the existing row if the input param 'conflictAlgorithm' =
* {@link #CONFLICT_IGNORE}
* OR -1 if any error
*/
public long insertWithOnConflict(String table, String nullColumnHack,
ContentValues initialValues, int conflictAlgorithm) {
acquireReference();
try {
StringBuilder sql = new StringBuilder();
sql.append("INSERT");
sql.append(CONFLICT_VALUES[conflictAlgorithm]);
sql.append(" INTO ");
sql.append(table);
sql.append('(');
Object[] bindArgs = null;
int size = (initialValues != null && initialValues.size() > 0)
? initialValues.size() : 0;
if (size > 0) {
bindArgs = new Object[size];
int i = 0;
for (String colName : initialValues.keySet()) {
sql.append((i > 0) ? "," : "");
sql.append(colName);
bindArgs[i++] = initialValues.get(colName);
}
sql.append(')');
sql.append(" VALUES (");
for (i = 0; i < size; i++) {
sql.append((i > 0) ? ",?" : "?");
}
} else {
sql.append(nullColumnHack + ") VALUES (NULL");
}
sql.append(')');
SQLiteStatement statement = new SQLiteStatement(this, sql.toString(), bindArgs);
try {
return statement.executeInsert();
} finally {
statement.close();
}
} finally {
releaseReference();
}
}
/**
* Convenience method for deleting rows in the database.
*
* @param table the table to delete from
* @param whereClause the optional WHERE clause to apply when deleting.
* Passing null will delete all rows.
* @param whereArgs You may include ?s in the where clause, which
* will be replaced by the values from whereArgs. The values
* will be bound as Strings.
* @return the number of rows affected if a whereClause is passed in, 0
* otherwise. To remove all rows and get a count pass "1" as the
* whereClause.
*/
public int delete(String table, String whereClause, String[] whereArgs) {
acquireReference();
try {
SQLiteStatement statement = new SQLiteStatement(this, "DELETE FROM " + table +
(!TextUtils.isEmpty(whereClause) ? " WHERE " + whereClause : ""), whereArgs);
try {
return statement.executeUpdateDelete();
} finally {
statement.close();
}
} finally {
releaseReference();
}
}
/**
* Convenience method for updating rows in the database.
*
* @param table the table to update in
* @param values a map from column names to new column values. null is a
* valid value that will be translated to NULL.
* @param whereClause the optional WHERE clause to apply when updating.
* Passing null will update all rows.
* @param whereArgs You may include ?s in the where clause, which
* will be replaced by the values from whereArgs. The values
* will be bound as Strings.
* @return the number of rows affected
*/
public int update(String table, ContentValues values, String whereClause, String[] whereArgs) {
return updateWithOnConflict(table, values, whereClause, whereArgs, CONFLICT_NONE);
}
/**
* Convenience method for updating rows in the database.
*
* @param table the table to update in
* @param values a map from column names to new column values. null is a
* valid value that will be translated to NULL.
* @param whereClause the optional WHERE clause to apply when updating.
* Passing null will update all rows.
* @param whereArgs You may include ?s in the where clause, which
* will be replaced by the values from whereArgs. The values
* will be bound as Strings.
* @param conflictAlgorithm for update conflict resolver
* @return the number of rows affected
*/
public int updateWithOnConflict(String table, ContentValues values,
String whereClause, String[] whereArgs, int conflictAlgorithm) {
if (values == null || values.size() == 0) {
throw new IllegalArgumentException("Empty values");
}
acquireReference();
try {
StringBuilder sql = new StringBuilder(120);
sql.append("UPDATE ");
sql.append(CONFLICT_VALUES[conflictAlgorithm]);
sql.append(table);
sql.append(" SET ");
// move all bind args to one array
int setValuesSize = values.size();
int bindArgsSize = (whereArgs == null) ? setValuesSize : (setValuesSize + whereArgs.length);
Object[] bindArgs = new Object[bindArgsSize];
int i = 0;
for (String colName : values.keySet()) {
sql.append((i > 0) ? "," : "");
sql.append(colName);
bindArgs[i++] = values.get(colName);
sql.append("=?");
}
if (whereArgs != null) {
for (i = setValuesSize; i < bindArgsSize; i++) {
bindArgs[i] = whereArgs[i - setValuesSize];
}
}
if (!TextUtils.isEmpty(whereClause)) {
sql.append(" WHERE ");
sql.append(whereClause);
}
SQLiteStatement statement = new SQLiteStatement(this, sql.toString(), bindArgs);
try {
return statement.executeUpdateDelete();
} finally {
statement.close();
}
} finally {
releaseReference();
}
}
/**
* Execute a single SQL statement that is NOT a SELECT
* or any other SQL statement that returns data.
*
* It has no means to return any data (such as the number of affected rows). * Instead, you're encouraged to use {@link #insert(String, String, ContentValues)}, * {@link #update(String, ContentValues, String, String[])}, et al, when possible. *
*
* When using {@link #enableWriteAheadLogging()}, journal_mode is
* automatically managed by this class. So, do not set journal_mode
* using "PRAGMA journal_mode'
* For INSERT statements, use any of the following instead. *
* For UPDATE statements, use any of the following instead. *
* For DELETE statements, use any of the following instead. *
* For example, the following are good candidates for using this method: *
* When using {@link #enableWriteAheadLogging()}, journal_mode is
* automatically managed by this class. So, do not set journal_mode
* using "PRAGMA journal_mode'
* Maximum cache size can ONLY be increased from its current size (default = 10). * If this method is called with smaller size than the current maximum value, * then IllegalStateException is thrown. *
* This method is thread-safe. * * @param cacheSize the size of the cache. can be (0 to {@link #MAX_SQL_CACHE_SIZE}) * @throws IllegalStateException if input cacheSize > {@link #MAX_SQL_CACHE_SIZE}. */ public void setMaxSqlCacheSize(int cacheSize) { if (cacheSize > MAX_SQL_CACHE_SIZE || cacheSize < 0) { throw new IllegalStateException( "expected value between 0 and " + MAX_SQL_CACHE_SIZE); } synchronized (mLock) { throwIfNotOpenLocked(); final int oldMaxSqlCacheSize = mConfigurationLocked.maxSqlCacheSize; mConfigurationLocked.maxSqlCacheSize = cacheSize; try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.maxSqlCacheSize = oldMaxSqlCacheSize; throw ex; } } } /** * Sets whether foreign key constraints are enabled for the database. *
* By default, foreign key constraints are not enforced by the database. * This method allows an application to enable foreign key constraints. * It must be called each time the database is opened to ensure that foreign * key constraints are enabled for the session. *
* A good time to call this method is right after calling {@link #openOrCreateDatabase} * or in the {@link SQLiteOpenHelper#onConfigure} callback. *
* When foreign key constraints are disabled, the database does not check whether * changes to the database will violate foreign key constraints. Likewise, when * foreign key constraints are disabled, the database will not execute cascade * delete or update triggers. As a result, it is possible for the database * state to become inconsistent. To perform a database integrity check, * call {@link #isDatabaseIntegrityOk}. *
* This method must not be called while a transaction is in progress. *
* See also SQLite Foreign Key Constraints * for more details about foreign key constraint support. *
* * @param enable True to enable foreign key constraints, false to disable them. * * @throws IllegalStateException if the are transactions is in progress * when this method is called. */ public void setForeignKeyConstraintsEnabled(boolean enable) { synchronized (mLock) { throwIfNotOpenLocked(); if (mConfigurationLocked.foreignKeyConstraintsEnabled == enable) { return; } mConfigurationLocked.foreignKeyConstraintsEnabled = enable; try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.foreignKeyConstraintsEnabled = !enable; throw ex; } } } /** * This method enables parallel execution of queries from multiple threads on the * same database. It does this by opening multiple connections to the database * and using a different database connection for each query. The database * journal mode is also changed to enable writes to proceed concurrently with reads. ** When write-ahead logging is not enabled (the default), it is not possible for * reads and writes to occur on the database at the same time. Before modifying the * database, the writer implicitly acquires an exclusive lock on the database which * prevents readers from accessing the database until the write is completed. *
* In contrast, when write-ahead logging is enabled (by calling this method), write * operations occur in a separate log file which allows reads to proceed concurrently. * While a write is in progress, readers on other threads will perceive the state * of the database as it was before the write began. When the write completes, readers * on other threads will then perceive the new state of the database. *
* It is a good idea to enable write-ahead logging whenever a database will be * concurrently accessed and modified by multiple threads at the same time. * However, write-ahead logging uses significantly more memory than ordinary * journaling because there are multiple connections to the same database. * So if a database will only be used by a single thread, or if optimizing * concurrency is not very important, then write-ahead logging should be disabled. *
* After calling this method, execution of queries in parallel is enabled as long as * the database remains open. To disable execution of queries in parallel, either * call {@link #disableWriteAheadLogging} or close the database and reopen it. *
* The maximum number of connections used to execute queries in parallel is * dependent upon the device memory and possibly other properties. *
* If a query is part of a transaction, then it is executed on the same database handle the * transaction was begun. *
* Writers should use {@link #beginTransactionNonExclusive()} or * {@link #beginTransactionWithListenerNonExclusive(SQLiteTransactionListener)} * to start a transaction. Non-exclusive mode allows database file to be in readable * by other threads executing queries. *
* If the database has any attached databases, then execution of queries in parallel is NOT * possible. Likewise, write-ahead logging is not supported for read-only databases * or memory databases. In such cases, {@link #enableWriteAheadLogging} returns false. *
* The best way to enable write-ahead logging is to pass the
* {@link #ENABLE_WRITE_AHEAD_LOGGING} flag to {@link #openDatabase}. This is
* more efficient than calling {@link #enableWriteAheadLogging}.
*
* SQLiteDatabase db = SQLiteDatabase.openDatabase("db_filename", cursorFactory,
* SQLiteDatabase.CREATE_IF_NECESSARY | SQLiteDatabase.ENABLE_WRITE_AHEAD_LOGGING,
* myDatabaseErrorHandler);
* db.enableWriteAheadLogging();
*
* Another way to enable write-ahead logging is to call {@link #enableWriteAheadLogging}
* after opening the database.
*
* SQLiteDatabase db = SQLiteDatabase.openDatabase("db_filename", cursorFactory,
* SQLiteDatabase.CREATE_IF_NECESSARY, myDatabaseErrorHandler);
* db.enableWriteAheadLogging();
*
* See also SQLite Write-Ahead Logging for * more details about how write-ahead logging works. *
* * @return True if write-ahead logging is enabled. * * @throws IllegalStateException if there are transactions in progress at the * time this method is called. WAL mode can only be changed when there are no * transactions in progress. * * @see #ENABLE_WRITE_AHEAD_LOGGING * @see #disableWriteAheadLogging */ public boolean enableWriteAheadLogging() { synchronized (mLock) { throwIfNotOpenLocked(); if ((mConfigurationLocked.openFlags & ENABLE_WRITE_AHEAD_LOGGING) != 0) { return true; } if (isReadOnlyLocked()) { // WAL doesn't make sense for readonly-databases. // TODO: True, but connection pooling does still make sense... return false; } if (mConfigurationLocked.isInMemoryDb()) { Log.i(TAG, "can't enable WAL for memory databases."); return false; } // make sure this database has NO attached databases because sqlite's write-ahead-logging // doesn't work for databases with attached databases if (mHasAttachedDbsLocked) { if (Log.isLoggable(TAG, Log.DEBUG)) { Log.d(TAG, "this database: " + mConfigurationLocked.label + " has attached databases. can't enable WAL."); } return false; } mConfigurationLocked.openFlags |= ENABLE_WRITE_AHEAD_LOGGING; try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.openFlags &= ~ENABLE_WRITE_AHEAD_LOGGING; throw ex; } } return true; } /** * This method disables the features enabled by {@link #enableWriteAheadLogging()}. * * @throws IllegalStateException if there are transactions in progress at the * time this method is called. WAL mode can only be changed when there are no * transactions in progress. * * @see #enableWriteAheadLogging */ public void disableWriteAheadLogging() { synchronized (mLock) { throwIfNotOpenLocked(); if ((mConfigurationLocked.openFlags & ENABLE_WRITE_AHEAD_LOGGING) == 0) { return; } mConfigurationLocked.openFlags &= ~ENABLE_WRITE_AHEAD_LOGGING; try { mConnectionPoolLocked.reconfigure(mConfigurationLocked); } catch (RuntimeException ex) { mConfigurationLocked.openFlags |= ENABLE_WRITE_AHEAD_LOGGING; throw ex; } } } /** * Returns true if write-ahead logging has been enabled for this database. * * @return True if write-ahead logging has been enabled for this database. * * @see #enableWriteAheadLogging * @see #ENABLE_WRITE_AHEAD_LOGGING */ public boolean isWriteAheadLoggingEnabled() { synchronized (mLock) { throwIfNotOpenLocked(); return (mConfigurationLocked.openFlags & ENABLE_WRITE_AHEAD_LOGGING) != 0; } } /** * Collect statistics about all open databases in the current process. * Used by bug report. */ static ArrayList* If the result is false, then this method logs the errors reported by the integrity_check * command execution. *
* Note that 'pragma integrity_check' on a database can take a long time.
*
* @return true if the given database (and all its attached databases) pass integrity_check,
* false otherwise.
*/
public boolean isDatabaseIntegrityOk() {
acquireReference();
try {
List