我有一个名为states的表。数据是这样的：
+----------------------+--------------------+
| value | name |
+----------------------+--------------------+
| andaman-nicobar-map | Andaman-Nicobar |
| andhra-pradesh-map | Andhra-Pradesh |
| arunachal-map | Arunachal |
| assam-map | Assam |
| bihar-map | Bihar |
| chandigarh-map | Chandigarh |
| chattisgarh-map | Chattisgarh |
| daman-map | Daman |
+----------------------+--------------------+
SELECT * FROM `states` WHERE `name`='Bihar';
但此查询返回一个空结果集。
答案 0 :(得分：0)
我的猜测是你在SELECT *
FROM states
WHERE TRIM(name) = 'Bihar'
列中有空格，这就是为什么确切的比较失败了。试试这个问题：
SELECT *
FROM states
WHERE name LIKE '%Bihar%'
或者这个：
name如果其中任何一项有效，那么您就会知道 class Program
{
static void Main(string[] args)
{
Maruti objMaruti = new Maruti();
clientClass obj = new clientClass(objMaruti);
obj.getSpeed();
}
}
public class clientClass
{
ISpeed _ISpeed;
public clientClass(ISpeed obj)
{
this._ISpeed = obj;
}
public int getSpeed()
{
return _ISpeed.Speed();
}
}
public interface ISpeed
{
int Speed();
}
public class Maruti : ISpeed
{
public int Speed()
{
return 200;
}
}
public class Audi : ISpeed
{
public int Speed()
{
return 400;
}
}
public class BMW : ISpeed
{
public int Speed()
{
return 600;
}
}
列中有额外的字符。