Question

我尝试获取具有搜索到的ID的行数。我用它来检查重复项。

我不确定如何将计数作为变量返回，以便我可以比较它。我有支票If cmd.ExecuteNonQuery() = 0 Then，但它总是-1。我尝试过制作Int row as Integer = cmd.ExecuteNonQuery()并始终为-1。

所以我的问题是......在我执行cmd.ExecuteNonQuery()之后如何获取计数金额的数据集值并将其分配给Dim count as Integer = ....

之类的值

存储过程：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

CREATE PROCEDURE UserCheck
-- Add the parameters for the stored procedure here
@ID bigint
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

   SELECT COUNT(*) FROM tbl WHERE ID= @ID;
END
GO

Vb.net

   Dim CS1 As String = ModuleGlobals.connectionString

    Using con As New SqlConnection(CS1)

        Dim cmd As New SqlCommand("dbo.UserCheck", con)
        con.Open()
        'specify that it is a stored procedure and not a normal proc
        cmd.CommandType = System.Data.CommandType.StoredProcedure

        cmd.Parameters.AddWithValue("@ID", TextBox3.Text)
        'Dim count As Integer = cmd.ExecuteNonQuery()

        If cmd.ExecuteNonQuery() = 0 Then

            Dim CS As String = ModuleGlobals.connectionString
            Using con2 As New SqlConnection(CS)

                Dim cmd2 As New SqlCommand("dbo.Create", con2)
                con2.Open()

                ...add parameters here

                cmd2.ExecuteNonQuery()
                con2.Close()
            End Using
        Else
            MsgBox("No user was created")
        End If
        con.Close()
    End Using

Answer 1

根据documentation for the ExecuteNonQuery() method：

对于更新， INSERT 和 DELETE 语句，返回值是受命令影响的行数。

[...]

对于所有其他类型的语句，返回值为-1 。如果发生回滚，则返回值也为-1。

由于您的存储过程只调用SELECT，因此它将始终返回-1。

如果我没弄错，你必须使用ExecuteScalar() method。

Dim count As Integer = CType(cmd.ExecuteScalar(), Integer)

返回存储过程值

1 个答案: