的Android的SQLite中刪除一行

Question

我的代碼：

public void droptablecontents(String category) 
{ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "DELETE FROM " + Table_Name + " WHERE " + KEY_CAT + "=" + category; 
    Cursor cursor = db.rawQuery(query, null); 
    cursor.moveToFirst(); 
    cursor.close(); 
} 

我的表的創建語句：

"CREATE TABLE IF NOT EXISTS " + Table_Name + "(" + KEY_NOTE + " TEXT, " + KEY_CAT + " TEXT" + ")" 

我的日誌貓錯誤：

android.database.sqlite.SQLiteException: no such column: Ideas (code 1): , while compiling: DELETE FROM Cats WHERE cat=Ideas 

但爲什麼它尋找一個列命名爲'想法'？我正在嘗試在KEY_CAT列中搜索值'Ideas'。

Answer 1

添加「'」爲條件，它是文本。

public void droptablecontents(String category) 
{ 
    SQLiteDatabase db = this.getWritableDatabase(); 
    String query = "DELETE FROM " + Table_Name + " WHERE " + KEY_CAT + "='" + category + "'"; 
    Cursor cursor = db.rawQuery(query, null); 
    cursor.moveToFirst(); 
    cursor.close(); 
}