[转载]Android中SQLite操作示例

[转载]Android中SQLite操作示例 – Android – mobile – ITeye论坛.

AndroidSQLite操作示例

Android中对SQLite数据库的操作,涉及以下几个方面:

1、确认数据库文件,即.db文件;

2、通过Android.database.SQLite. SQLiteDatabase类的openOrCreateDatabase()方法打开数据库;

3、数据库操作:

A、开始事务: SQLiteDatabase.beginTransaction();

B、执行sql语句;

C、结束事务: SQLiteDatabase.endTransaction();

具体代码可参考如下:

static boolean installDefaultSitesToDB(Context cxt) {
	// 确认目标数据库文件
	File path = cxt.getDir("databases", Context.MODE_WORLD_WRITEABLE);
	path = new File(path, "db_name.db");

	
	SQLiteDatabase db = null;
	try {
              // 打开数据库
               db = openDB(path.getAbsolutePath());
		if (db == null) {
			//Log.e("tag", "open db_name.db ERROR~");
			return false;
		}

		db.beginTransaction();//开始事务

                boolean bool = doInstallData(db);//执行sql语句,插入数据

               //设置事务标志
                if (bool) {
			db.setTransactionSuccessful();// 设置事务标志
		} else {
			//Log.w("tag", "doInstall.DEFAULT_SITES Fail~!");
		}
		return bool;
	} finally {
		if (db != null) {
                        //结束事务
			if (db.inTransaction()) {db.endTransaction();}
			db.close();
		}
	}
}

private static SQLiteDatabase openDB(String file) {
	try {
		//SQLiteDatabase.openOrCreateDatabase(file, null);
		int flag = SQLiteDatabase.OPEN_READWRITE;
		flag = flag | SQLiteDatabase.CREATE_IF_NECESSARY;
		flag = flag | SQLiteDatabase.NO_LOCALIZED_COLLATORS;
		SQLiteDatabase db = SQLiteDatabase.openDatabase(file, null, flag);
		return db;
	} catch (Throwable e) {
		//Log.e("tag","openDatabase error:" + e.getMessage());
		return null;
	}
}	

//
private static boolean doInstallData(SQLiteDatabase db) {
	try {
		//create table
		String sql = "CREATE TABLE IF NOT EXISTS Permissions (origin TEXT UNIQUE NOT NULL, allow INTEGER NOT NULL)";
		db.execSQL(sql);
		
		ContentValues cv = new ContentValues();
		for (String site : DEFAULT_SITES) {
			cv.clear();
			cv.put("origin", site);
			cv.put("allow", 1);
			long ret = 	db.insertOrThrow("Permissions", null, cv);
			Log.d("tag", "db.insert.RET:" + ret);
		}
		return true;
	} catch (SQLException se) {
		String msg = "doInstall.error:[%s].%s";
		Log.d("tag",String.format(msg, se.getClass(),se.getMessage()));
		return false;
	}
}
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