Added in API level 1

Summary: Ctors | Methods | Inherited Methods

SQLiteOpenHelper

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Kotlin |Java

public abstract class SQLiteOpenHelper
extends Object implements AutoCloseable

java.lang.Object
↳	android.database.sqlite.SQLiteOpenHelper

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A helper class to manage database creation and version management.

You create a subclass implementing onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int) and optionally onOpen(SQLiteDatabase), and this class takes care of opening the database if it exists, creating it if it does not, and upgrading it as necessary. Transactions are used to make sure the database is always in a sensible state.

This class makes it easy for ContentProvider implementations to defer opening and upgrading the database until first use, to avoid blocking application startup with long-running database upgrades.

For an example, see the NotePadProvider class in the NotePad sample application, in the samples/ directory of the SDK.

Note: this class assumes monotonically increasing version numbers for upgrades.

Note: the AutoCloseable interface was first added in the Build.VERSION_CODES.Q release.

Summary

Public constructors
SQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) Create a helper object to create, open, and/or manage a database.
SQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version, DatabaseErrorHandler errorHandler) Create a helper object to create, open, and/or manage a database.
SQLiteOpenHelper(Context context, String name, int version, SQLiteDatabase.OpenParams openParams) Create a helper object to create, open, and/or manage a database.

Public methods
void	close() Close any open database object.
String	getDatabaseName() Return the name of the SQLite database being opened, as given to the constructor.
SQLiteDatabase	getReadableDatabase() Create and/or open a database.
SQLiteDatabase	getWritableDatabase() Create and/or open a database that will be used for reading and writing.
void	onConfigure(SQLiteDatabase db) Called when the database connection is being configured, to enable features such as write-ahead logging or foreign key support.
abstract void	onCreate(SQLiteDatabase db) Called when the database is created for the first time.
void	onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) Called when the database needs to be downgraded.
void	onOpen(SQLiteDatabase db) Called when the database has been opened.
abstract void	onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) Called when the database needs to be upgraded.
void	setIdleConnectionTimeout(long idleConnectionTimeoutMs) This method was deprecated in API level 29. DO NOT USE this method. See the javadoc of SQLiteDatabase.OpenParams.Builder.setIdleConnectionTimeout(long) for the details.
void	setLookasideConfig(int slotSize, int slotCount) Configures lookaside memory allocator This method should be called from the constructor of the subclass, before opening the database, since lookaside memory configuration can only be changed when no connection is using it SQLite default settings will be used, if this method isn't called.
void	setOpenParams(SQLiteDatabase.OpenParams openParams) Sets configuration parameters that are used for opening SQLiteDatabase.
void	setWriteAheadLoggingEnabled(boolean enabled) Enables or disables the use of write-ahead logging for the database.

Inherited methods
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait(long timeoutMillis, int nanos) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait(long timeoutMillis) Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed. final void wait() Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
From interface java.lang.AutoCloseable abstract void close() Closes this resource, relinquishing any underlying resources.

Public constructors

SQLiteOpenHelper

Added in API level 1

public SQLiteOpenHelper (Context context, 
                String name, 
                SQLiteDatabase.CursorFactory factory, 
                int version)

Create a helper object to create, open, and/or manage a database. This method always returns very quickly. The database is not actually created or opened until one of getWritableDatabase() or getReadableDatabase() is called.

Parameters
context	Context: to use for locating paths to the the database This value may be null.
name	String: of the database file, or null for an in-memory database
factory	SQLiteDatabase.CursorFactory: to use for creating cursor objects, or null for the default
version	int: number of the database (starting at 1); if the database is older, onUpgrade(SQLiteDatabase, int, int) will be used to upgrade the database; if the database is newer, onDowngrade(SQLiteDatabase, int, int) will be used to downgrade the database

SQLiteOpenHelper

Added in API level 11

public SQLiteOpenHelper (Context context, 
                String name, 
                SQLiteDatabase.CursorFactory factory, 
                int version, 
                DatabaseErrorHandler errorHandler)

Create a helper object to create, open, and/or manage a database. The database is not actually created or opened until one of getWritableDatabase() or getReadableDatabase() is called.

Accepts input param: a concrete instance of DatabaseErrorHandler to be used to handle corruption when sqlite reports database corruption.

Parameters
context	Context: to use for locating paths to the the database This value may be null.
name	String: of the database file, or null for an in-memory database
factory	SQLiteDatabase.CursorFactory: to use for creating cursor objects, or null for the default
version	int: number of the database (starting at 1); if the database is older, onUpgrade(SQLiteDatabase, int, int) will be used to upgrade the database; if the database is newer, onDowngrade(SQLiteDatabase, int, int) will be used to downgrade the database
errorHandler	DatabaseErrorHandler: the DatabaseErrorHandler to be used when sqlite reports database corruption, or null to use the default error handler.

SQLiteOpenHelper

Added in API level 28

public SQLiteOpenHelper (Context context, 
                String name, 
                int version, 
                SQLiteDatabase.OpenParams openParams)

Create a helper object to create, open, and/or manage a database. This method always returns very quickly. The database is not actually created or opened until one of getWritableDatabase() or getReadableDatabase() is called.

Parameters
context	Context: to use for locating paths to the the database This value may be null.
name	String: of the database file, or null for an in-memory database
version	int: number of the database (starting at 1); if the database is older, onUpgrade(SQLiteDatabase, int, int) will be used to upgrade the database; if the database is newer, onDowngrade(SQLiteDatabase, int, int) will be used to downgrade the database
openParams	SQLiteDatabase.OpenParams: configuration parameters that are used for opening SQLiteDatabase. Please note that SQLiteDatabase.CREATE_IF_NECESSARY flag will always be set when the helper opens the database This value cannot be null.

Public methods

close

Added in API level 1

public void close ()

Close any open database object.

getDatabaseName

Added in API level 14

public String getDatabaseName ()

Return the name of the SQLite database being opened, as given to the constructor.

Returns
String

getReadableDatabase

Added in API level 1

public SQLiteDatabase getReadableDatabase ()

Create and/or open a database. This will be the same object returned by getWritableDatabase() unless some problem, such as a full disk, requires the database to be opened read-only. In that case, a read-only database object will be returned. If the problem is fixed, a future call to getWritableDatabase() may succeed, in which case the read-only database object will be closed and the read/write object will be returned in the future.

Like getWritableDatabase(), this method may take a long time to return, so you should not call it from the application main thread, including from ContentProvider.onCreate().

Returns
SQLiteDatabase	a database object valid until getWritableDatabase() or close() is called.

Throws
SQLiteException	if the database cannot be opened

getWritableDatabase

Added in API level 1

public SQLiteDatabase getWritableDatabase ()

Create and/or open a database that will be used for reading and writing. The first time this is called, the database will be opened and onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int) and/or onOpen(SQLiteDatabase) will be called.

Once opened successfully, the database is cached, so you can call this method every time you need to write to the database. (Make sure to call close() when you no longer need the database.) Errors such as bad permissions or a full disk may cause this method to fail, but future attempts may succeed if the problem is fixed.

Database upgrade may take a long time, you should not call this method from the application main thread, including from ContentProvider.onCreate().

Returns
SQLiteDatabase	a read/write database object valid until close() is called

Throws
SQLiteException	if the database cannot be opened for writing

onConfigure

Added in API level 16

public void onConfigure (SQLiteDatabase db)

Called when the database connection is being configured, to enable features such as write-ahead logging or foreign key support.

This method is called before onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int), onDowngrade(SQLiteDatabase, int, int), or onOpen(SQLiteDatabase) are called. It should not modify the database except to configure the database connection as required.

This method should only call methods that configure the parameters of the database connection, such as SQLiteDatabase.enableWriteAheadLogging SQLiteDatabase.setForeignKeyConstraintsEnabled, SQLiteDatabase.setLocale, SQLiteDatabase.setMaximumSize, or executing PRAGMA statements.

Parameters
db	SQLiteDatabase: The database.

onCreate

Added in API level 1

public abstract void onCreate (SQLiteDatabase db)

Called when the database is created for the first time. This is where the creation of tables and the initial population of the tables should happen.

Parameters
db	SQLiteDatabase: The database.

onDowngrade

Added in API level 11

public void onDowngrade (SQLiteDatabase db, 
                int oldVersion, 
                int newVersion)

Called when the database needs to be downgraded. This is strictly similar to onUpgrade(SQLiteDatabase, int, int) method, but is called whenever current version is newer than requested one. However, this method is not abstract, so it is not mandatory for a customer to implement it. If not overridden, default implementation will reject downgrade and throws SQLiteException

This method executes within a transaction. If an exception is thrown, all changes will automatically be rolled back.

Parameters
db	SQLiteDatabase: The database.
oldVersion	int: The old database version.
newVersion	int: The new database version.

onOpen

Added in API level 1

public void onOpen (SQLiteDatabase db)

Called when the database has been opened. The implementation should check SQLiteDatabase.isReadOnly before updating the database.

This method is called after the database connection has been configured and after the database schema has been created, upgraded or downgraded as necessary. If the database connection must be configured in some way before the schema is created, upgraded, or downgraded, do it in onConfigure(SQLiteDatabase) instead.

Parameters
db	SQLiteDatabase: The database.

onUpgrade

Added in API level 1

public abstract void onUpgrade (SQLiteDatabase db, 
                int oldVersion, 
                int newVersion)

Called when the database needs to be upgraded. The implementation should use this method to drop tables, add tables, or do anything else it needs to upgrade to the new schema version.

The SQLite ALTER TABLE documentation can be found here. If you add new columns you can use ALTER TABLE to insert them into a live table. If you rename or remove columns you can use ALTER TABLE to rename the old table, then create the new table and then populate the new table with the contents of the old table.

This method executes within a transaction. If an exception is thrown, all changes will automatically be rolled back.

Important: You should NOT modify an existing migration step from version X to X+1 once a build has been released containing that migration step. If a migration step has an error and it runs on a device, the step will NOT re-run itself in the future if a fix is made to the migration step.

For example, suppose a migration step renames a database column from foo to bar when the name should have been baz. If that migration step is released in a build and runs on a user's device, the column will be renamed to bar. If the developer subsequently edits this same migration step to change the name to baz as intended, the user devices which have already run this step will still have the name bar. Instead, a NEW migration step should be created to correct the error and rename bar to baz, ensuring the error is corrected on devices which have already run the migration step with the error.

Parameters
db	SQLiteDatabase: The database.
oldVersion	int: The old database version.
newVersion	int: The new database version.

setIdleConnectionTimeout

Added in API level 27
Deprecated in API level 29

public void setIdleConnectionTimeout (long idleConnectionTimeoutMs)

This method was deprecated in API level 29.
DO NOT USE this method. See the javadoc of SQLiteDatabase.OpenParams.Builder.setIdleConnectionTimeout(long) for the details.

Sets the maximum number of milliseconds that SQLite connection is allowed to be idle before it is closed and removed from the pool.

This method should be called from the constructor of the subclass, before opening the database

DO NOT USE this method. This feature has negative side effects that are very hard to foresee. See the javadoc of SQLiteDatabase.OpenParams.Builder.setIdleConnectionTimeout(long) for the details.

Parameters
idleConnectionTimeoutMs	long: timeout in milliseconds. Use Long.MAX_VALUE value to allow unlimited idle connections. Value is 0 or greater

See also:

• SQLiteDatabase.OpenParams.Builder.setIdleConnectionTimeout(long)

setLookasideConfig

Added in API level 27

public void setLookasideConfig (int slotSize, 
                int slotCount)

Configures lookaside memory allocator

This method should be called from the constructor of the subclass, before opening the database, since lookaside memory configuration can only be changed when no connection is using it

SQLite default settings will be used, if this method isn't called. Use setLookasideConfig(0,0) to disable lookaside

Note: Provided slotSize/slotCount configuration is just a recommendation. The system may choose different values depending on a device, e.g. lookaside allocations can be disabled on low-RAM devices

Parameters
slotSize	int: The size in bytes of each lookaside slot. Value is 0 or greater
slotCount	int: The total number of lookaside memory slots per database connection. Value is 0 or greater

setOpenParams

Added in API level 28

public void setOpenParams (SQLiteDatabase.OpenParams openParams)

Sets configuration parameters that are used for opening SQLiteDatabase.

Please note that SQLiteDatabase.CREATE_IF_NECESSARY flag will always be set when opening the database

Parameters
openParams	SQLiteDatabase.OpenParams: configuration parameters that are used for opening SQLiteDatabase. This value cannot be null.

Throws
IllegalStateException	if the database is already open

setWriteAheadLoggingEnabled

Added in API level 16

public void setWriteAheadLoggingEnabled (boolean enabled)

Enables or disables the use of write-ahead logging for the database. 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.

Parameters
enabled	boolean: True if write-ahead logging should be enabled, false if it should be disabled.

See also:

• SQLiteDatabase.enableWriteAheadLogging()