Java tutorial
/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.database.sqlite; import android.annotation.UnsupportedAppUsage; import android.os.ParcelFileDescriptor; /** * Represents a statement that can be executed against a database. The statement * cannot return multiple rows or columns, but single value (1 x 1) result sets * are supported. * <p> * This class is not thread-safe. * </p> */ public final class SQLiteStatement extends SQLiteProgram { @UnsupportedAppUsage SQLiteStatement(SQLiteDatabase db, String sql, Object[] bindArgs) { super(db, sql, bindArgs, null); } /** * Execute this SQL statement, if it is not a SELECT / INSERT / DELETE / UPDATE, for example * CREATE / DROP table, view, trigger, index etc. * * @throws android.database.SQLException If the SQL string is invalid for * some reason */ public void execute() { acquireReference(); try { getSession().execute(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } /** * Execute this SQL statement, if the number of rows affected by execution of this SQL * statement is of any importance to the caller - for example, UPDATE / DELETE SQL statements. * * @return the number of rows affected by this SQL statement execution. * @throws android.database.SQLException If the SQL string is invalid for * some reason */ public int executeUpdateDelete() { acquireReference(); try { return getSession().executeForChangedRowCount(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } /** * Execute this SQL statement and return the ID of the row inserted due to this call. * The SQL statement should be an INSERT for this to be a useful call. * * @return the row ID of the last row inserted, if this insert is successful. -1 otherwise. * * @throws android.database.SQLException If the SQL string is invalid for * some reason */ public long executeInsert() { acquireReference(); try { return getSession().executeForLastInsertedRowId(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } /** * Execute a statement that returns a 1 by 1 table with a numeric value. * For example, SELECT COUNT(*) FROM table; * * @return The result of the query. * * @throws android.database.sqlite.SQLiteDoneException if the query returns zero rows */ public long simpleQueryForLong() { acquireReference(); try { return getSession().executeForLong(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } /** * Execute a statement that returns a 1 by 1 table with a text value. * For example, SELECT COUNT(*) FROM table; * * @return The result of the query. * * @throws android.database.sqlite.SQLiteDoneException if the query returns zero rows */ public String simpleQueryForString() { acquireReference(); try { return getSession().executeForString(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } /** * Executes a statement that returns a 1 by 1 table with a blob value. * * @return A read-only file descriptor for a copy of the blob value, or {@code null} * if the value is null or could not be read for some reason. * * @throws android.database.sqlite.SQLiteDoneException if the query returns zero rows */ public ParcelFileDescriptor simpleQueryForBlobFileDescriptor() { acquireReference(); try { return getSession().executeForBlobFileDescriptor(getSql(), getBindArgs(), getConnectionFlags(), null); } catch (SQLiteDatabaseCorruptException ex) { onCorruption(); throw ex; } finally { releaseReference(); } } @Override public String toString() { return "SQLiteProgram: " + getSql(); } }