我将mConstr内容复制到mysql-Front中查询,返回结果为4,但在C#中进行如下查询返回结果(mCount)为0;
若将mConstr内容改为SELECT COUNT(*) FROM `abc` WHERE conclusion = '合格',查询结果为10返回也为10(正确),
数据库采用是mysql 5.0 用mysql.net连接的,
请高手指点一下原因,(好像SQL语句中有in关键字就总返回0)
//代码如下
mConstr="SELECT COUNT(*) FROM `abc` WHERE conclusion = '合格' And id IN( SELECT caseid FROM `caseinfo` WHERE name='ywyw')" ; conn.Open();
cmd = new MySqlCommand(mConstr,conn);
using (MySqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
mCount=reader.IsDBNull(0)? 0: reader.GetInt32(0);
}
reader.Close();
}
conn.Close();
return mCount;
若将mConstr内容改为SELECT COUNT(*) FROM `abc` WHERE conclusion = '合格',查询结果为10返回也为10(正确),
数据库采用是mysql 5.0 用mysql.net连接的,
请高手指点一下原因,(好像SQL语句中有in关键字就总返回0)
//代码如下
mConstr="SELECT COUNT(*) FROM `abc` WHERE conclusion = '合格' And id IN( SELECT caseid FROM `caseinfo` WHERE name='ywyw')" ; conn.Open();
cmd = new MySqlCommand(mConstr,conn);
using (MySqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
mCount=reader.IsDBNull(0)? 0: reader.GetInt32(0);
}
reader.Close();
}
conn.Close();
return mCount;
查询有结果吗?