数据库查询错误

Question

谁帮我看看啊，这个老是返回值为-1，一调试，就叫我重启vs什么问题啊，急求帮助！！   public int ValidateAdmin(string sql, string adminID,string adminPwd)        {            int i;            try            {                this.openCon();                this.cmd = new SqlCommand(sql, this.con);                this.cmd.CommandType = CommandType.StoredProcedure;                SqlParameter[] pars = new SqlParameter[] {                     new SqlParameter("@AdminID", SqlDbType.VarChar,50),                     new SqlParameter("@AdminPwd", SqlDbType.VarChar,50)                };                pars[0].Value = adminID;                pars[1].Value = adminPwd;                foreach (SqlParameter parameter in pars)                {                    this.cmd.Parameters.Add(parameter);                }                i = (int)this.cmd.ExecuteScalar();            }            catch            {                i = -1;            }            finally            {                this.closeCon();            }            return i;        }           public void openCon()        {            if (this.con == null)            {                this.con = new SqlConnection(this.strCon);            }            if (this.con.State.Equals(ConnectionState.Closed))            {                this.con.Open();            }        }

Answer 1

判断一下   this.cmd.ExecuteScalar(); 是否为NULL，再做 i = (int)this.cmd.ExecuteScalar();转换。

Answer 2

数据库查询出错了，跳入catch代码块了

Answer 3

@小柑: this.cmd = new SqlCommand(sql, this.con);  这个sql语句有没有错

Answer 4

@┢┦偉: 没有错  我突然发现  this.cmd.ExecuteScalar()不为空   改成下面  能获得i=1

  if (this.cmd.ExecuteScalar() != null)
                {
                    i = 1;//原来是i = (int)this.cmd.ExecuteScalar();                 }

Answer 5

@小柑: 谢谢了  总算解决这个问题了

Answer 6

@小柑: 不会有负值，0或>0

Answer 7

如果返回不为空给返回值赋值，不是把this.cmd.ExecuteScalar()的值直接返回去，因为不知道会返回什么值