Question

startTime和endTime是格式为“2011-07-22 13:00:00”的字符串。以下代码使myCursor.moveToFirst（）返回false。

String sqlQuery = "SELECT * FROM myData WHERE 
    strftime('%Y-%m-%d %H:%M:%S', datetime) >= strftime('%Y-%m-%d %H:%M:%S', '"+startTime+"') 
    AND strftime('%Y-%m-%d %H:%M:%S', datetime) <= strftime('%Y-%m-%d %H:%M:%S', '"+endTime+"')";
Cursor myCursor = myDataBase.rawQuery(sqlQuery, null);

但是，当我进入sqlite3 shell并输入

时

SELECT * FROM myData WHERE 
    strftime('%Y-%m-%d %H:%M:%S', datetime) >= strftime('%Y-%m-%d %H:%M:%S', '2011-07-22 13:00:00') 
    AND strftime('%Y-%m-%d %H:%M:%S', datetime) <= strftime('%Y-%m-%d %H:%M:%S', '2011-07-22 13:02:00');

它打印出我需要的东西。怎么了？

Answer 1

您是否错过了moveToFirst()来电？

String sqlQuery = "SELECT * FROM myData WHERE 
    strftime('%Y-%m-%d %H:%M:%S', datetime) >= strftime('%Y-%m-%d %H:%M:%S', '"+startTime+"') 
    AND strftime('%Y-%m-%d %H:%M:%S', datetime) <= strftime('%Y-%m-%d %H:%M:%S', '"+endTime+"')";
Cursor myCursor = myDataBase.rawQuery(sqlQuery, null);
myCursor.moveToFirst();  //

为什么我的Cursor在此SQLite数据库查询后为空？

1 个答案: