Android實現創建或升級數據庫時執行語句

本文實例講述了Android創建或升級數據庫時執行的語句，如果是創建或升級數據庫，請使用帶List參數的構造方法，帶SQL語句的構造方法將在數據庫創建或升級時執行。

具體程序代碼如下：

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;
 /**
 * 創建或升級數據庫時執行的語句。
 */
 private List<String> sqlStatementExed;
 /**
 * 如果是創建或升級數據庫，請使用帶List參數的構造方法。
 * 
 * @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;
 }
 /**
 * 帶SQL語句的構造方法。此SQL語句將在數據庫創建或升級時執行。
 * 
 * @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
 *      在數據庫創建或升級的時候將執行的語句。
 */
 public SimpleSQLiteOpenHelper(Context context, String name,
  CursorFactory factory, int version, List<String> sqlStatementExed) {
 super(context, name, factory, version);
 this.sqlStatementExed = sqlStatementExed;
 }
 /**
 * 如果是創建或升級數據庫，請使用帶List參數的構造方法。
 * @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;
 }
 /**
 * 如果是創建或升級數據庫，請使用帶List參數的構造方法。
 * @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;
 }
 /**
 * 如果是創建或升級數據庫，請使用帶List參數的構造方法。
 * 
 * @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
 *      在創建或升級數據庫時要執行的語句。
 */
 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
 *      在創建或升級數據庫時要執行的語句。
 */
 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);
 }
 }
 /**
 * 初始化或升級數據庫時執行的SQL語句。。
 */
 private void exeSqlStatementExed(SQLiteDatabase db) {
 if (sqlStatementExed != null) {
  for (String statement : sqlStatementExed) {
  db.execSQL(statement);
  }
 }
 }
}

希望本文所述方法對於大家進行Android程序開發能夠起到一定的幫助作用。