Question

我想在SQLite中更新一些数据。这是编辑数据的代码：

db.open();
c = db.getData();
if (c.moveToFirst()) {
    do {
        Log.v("_______BACK PRESSED", "______UUID___________"+c.getString(c.getColumnIndex("uuid")));
        Log.v("_______pos", "______UUID___________"+pos);
        String strSQL = "UPDATE DeviceDetails SET devicename ="+ edittext.getText().toString() +"  WHERE uuid = "+c.getString(c.getColumnIndex("uuid")) ;

        db.select(strSQL);
        Log.v("_______BACK PRESSED", "______UUID___________"+c.getString(c.getColumnIndex("uuid")));
        Log.v("_______BACK PRESSED", "______devicename___________"+c.getString(c.getColumnIndex("devicename")));

        Log.v("___________text", "_______________"+c.getString(c.getColumnIndex("devicename")));
        Log.v("___________edittext", "_______________"+edittext.getText().toString());
        Log.v("_____ADDRESS______edittext", "_______________"+pos);
        Intent intent=new Intent();
        intent.putExtra("Dname", edittext.getText().toString());
        Log.v("_____edittext in intent________", "__________"+edittext.getText().toString());
        intent.putExtra("Daddress",pos);
        Log.v("_____edittext in intent________", "__________"+pos);
        setResult(RESULT_OK, intent);
        finish();
    } while (c.moveToNext());
}

db.close();

在数据库适配器中，我执行以下操作来执行查询。但它没有更新数据。

public Cursor select(String query) throws SQLException {
    return db.rawQuery(query, null);
}

Answer 1

SQL引用的字符串文字不正确''。但是，最好的选择是使用?占位符和绑定参数。
使用execSQL()而非rawQuery()进行更新。单独rawQuery()就不会运行SQL; execSQL()会。

示例：

db.execSQL("UPDATE DeviceDetails SET devicename = ? WHERE uuid = ?",
    new String[] {
        edittext.getText().toString(),
        c.getString(c.getColumnIndex("uuid"))
    });

Answer 2

重命名简单更新

是什么意思？

并且更新查询将在您执行此操作时执行此操作

只需使用此

更新您的查询

String strSQL = "UPDATE DeviceDetails SET devicename ='"+ edittext.getText().toString() +"'  WHERE uuid = '"+c.getString(c.getColumnIndex("uuid"))+"'" ;

Answer 3

您应该使用.update更新数据库中的行而不是.rawQuery

String value = c.getString(c.getColumnIndex("uuid"));
String[] whereVars = new String[]{value};
String where = "uuid = ?"

ContentValues args = new ContentValues();
args.put("devicename", edittext.getText().toString());

db.update("DeviceDetails", args, where, whereVars);

我还会告诉您，上述代码的性能，循环中的更新，将是废话..所以您应该在单个事务中执行所有更新：

db.beginTransaction();
try {
    if (c.moveToFirst()) {
        do {
            updateDeviceByUuid(c.getString(c.getColumnIndex("uuid"),  
                               edittext.getText().toString());
        } while (c.moveToNext());
    }
    db.setTransactionSuccessful();
} finally {
    db.endTransaction();
}

和

public int updateDeviceByUuid(String uuid, String deviceName){
    String[] whereVars = new String[]{uuid};
    String where = "uuid = ?"

    ContentValues args = new ContentValues();
    args.put("devicename", deviceName);

    return db.update("DeviceDetails", args, where, whereVars);
}

如何使用SQLite中的特定ID更新数据

3 个答案: