本文实例讲述了Android创建或升级数据库时执行的语句，如果是创建或升级数据库，请使用带List参数的构造方法，带SQL语句的构造方法将在数据库创建或升级时执行。
具体程序代码如下：
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import java.util.List;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;public class SimpleSQLiteOpenHelper extends SQLiteOpenHelper { private static final int INIT_VERSION = 1; /** * 创建或升级数据库时执行的语句。 */ private List<String> sqlStatementExed; /** * 如果是创建或升级数据库，请使用带List参数的构造方法。 * * @param context * to use to open or create the database * @param name * of the database file, or null for an in-memory database * @param factory * to use for creating cursor objects, or null for the default * @param version * 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 */ public SimpleSQLiteOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); sqlStatementExed = null; } /** * 带SQL语句的构造方法。此SQL语句将在数据库创建或升级时执行。 * * @param context * to use to open or create the database * @param name * of the database file, or null for an in-memory database * @param factory * to use for creating cursor objects, or null for the default * @param version * 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 * @param sqlStatementExed * 在数据库创建或升级的时候将执行的语句。 */ public SimpleSQLiteOpenHelper(Context context, String name, CursorFactory factory, int version, List<String> sqlStatementExed) { super(context, name, factory, version); this.sqlStatementExed = sqlStatementExed; } /** * 如果是创建或升级数据库，请使用带List参数的构造方法。 * @param context * to use to open or create the database * @param name * of the database file, or null for an in-memory database * @param version * 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 */ public SimpleSQLiteOpenHelper(Context context, String name, int version) { super(context, name, null, version); sqlStatementExed = null; } /** * 如果是创建或升级数据库，请使用带List参数的构造方法。 * @param context * to use to open or create the database * @param name * of the database file, or null for an in-memory database */ public SimpleSQLiteOpenHelper(Context context, String name) { super(context, name, null, INIT_VERSION); sqlStatementExed = null; } /** * 如果是创建或升级数据库，请使用带List参数的构造方法。 * * @param context * to use to open or create the database * @param name * of the database file, or null for an in-memory database * @param version * 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 * @param sqlCreateStatement * 在创建或升级数据库时要执行的语句。 */ public SimpleSQLiteOpenHelper(Context context, String name, int version, List<String> sqlCreateStatement) { super(context, name, null, version); this.sqlStatementExed = sqlCreateStatement; } /** * @param context * @param name * @param sqlCreateStatement * 在创建或升级数据库时要执行的语句。 */ public SimpleSQLiteOpenHelper(Context context, String name, List<String> sqlCreateStatement) { super(context, name, null, INIT_VERSION); this.sqlStatementExed = sqlCreateStatement; } /* * (non-Javadoc) * @see * android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite * .SQLiteDatabase) */ @Override @Deprecated public void onCreate(SQLiteDatabase db) { exeSqlStatementExed(db); } /* * (non-Javadoc) * @see * android.database.sqlite.SQLiteOpenHelper#onUpgrade(android.database.sqlite * .SQLiteDatabase, int, int) */ @Override @Deprecated public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { if (newVersion > oldVersion) { exeSqlStatementExed(db); } } /** * 初始化或升级数据库时执行的SQL语句。。 */ private void exeSqlStatementExed(SQLiteDatabase db) { if (sqlStatementExed != null) { for (String statement : sqlStatementExed) { db.execSQL(statement); } } }} |
希望本文所述方法对于大家进行Android程序开发能够起到一定的帮助作用。
