android - 尝试从 SQLite 数据库中删除最后一行时出现语法错误 (code1)

Question

我试图从 SQLite 数据库表中删除最后一行，但我一直收到错误。有人能找到我的语法错误吗？

找到最大值

private String MAXID = COLUMN_ID + "=" + "SELECT MAX("+COLUMN_ID+") FROM "+TABLE_NAME+")";

删除状态

public void deleteLastRow(){
    try{
        ourDatabase.delete(TABLE_NAME, MAXID, null);

    }
    catch(Exception e){
        e.printStackTrace();
        Log.e("Deleteing last row", e.toString());
    }
}

错误日志

 09-13 12:53:14.570: E/Deleteing last row(2045): android.database.sqlite.SQLiteException: near "SELECT": syntax error (code 1): , while compiling: DELETE FROM gradest WHERE _id=SELECT MAX(_id) FROM gradest)

Answer 1

子查询必须总是括在圆括号中:

DELETE FROM gradest WHERE _id = (SELECT MAX(_id) FROM gradest)