代码:
string strSal = "select conut(*) from Admin where LoginId = '"+userName+" '
and LoginPwd = '""+pwd+'";
conn.Open();
SqlCommand comm = new SqlCommand(strSql,conn)
int iRet = (int)comm.ExecuteScalar();
其中 UserName是用户名 pwd 是密码 conn 是数据库连接对象连接对象
string strSal = "select conut(*) from Admin where LoginId = '"+userName+" '
and LoginPwd = '""+pwd+'";
这一句为什么要打单引号‘’
int iRet = (int)comm.ExecuteScalar();
这句为什么要强转,强转之前 comm 是字符串类型? 还是 对象也是一种类型?