當試圖從SQLite數據庫中刪除最後一行時出現語法錯誤（code1）

Question

我想從SQLite數據庫表中刪除最後一行，但不斷收到錯誤。有人可以找到我的語法錯誤嗎？

找到MAXID

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

DELETE Staement

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

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

錯誤日誌

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

子查詢必須始終被在括號括起來：

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