如何将vb.net的输出参数传递给mysql存储过程？

Question

我使用.NET连接器与MySQL 5.5。当我尝试调用存储过程与“出”的参数，我得到的消息OUT or INOUT argument 2 for routine名is not a variable or NEW pseudo-variable in BEFORE trigger在cmd.ExecuteNonQuery()。

出了什么问题？

VB代码：

cmd = New MySqlCommand("call testme(@id, @count)", conn) 
cmd.Parameters.AddWithValue("@id", id) ' "id" and "count" are integer variables 
cmd.Parameters.AddWithValue("@count", count) 
cmd.Parameters("@count").Direction = ParameterDirection.Output 
cmd.ExecuteNonQuery() 

MySQL的存储过程：

CREATE PROCEDURE testme(in taxid integer, out imageDescCount integer) 
BEGIN 
set imageDescCount = 23; 
End 

Answer 1

请试试这个

在MySQL中创建存储过程像

DELIMITER $$ 
DROP PROCEDURE IF EXISTS `tempdb`.`GetCity` $$ 
CREATE PROCEDURE `tempdb`.`GetCity` 
(IN cid INT, 
OUT cname VarChar(50) 
) 

BEGIN 

    SET cname = (SELECT CityName FROM `City` WHERE CID = cid); 

END $$ 

DELIMITER ; 

和你vb.net代码如

Dim conn As New MySqlConnection() 
conn.ConnectionString = "server=localhost;user=root;database=tempdb;port=3306;password=******;" 
Dim cmd As New MySqlCommand() 

conn.Open() 
cmd.Connection = conn 
cmd.CommandText = "GetCity" 
cmd.CommandType = CommandType.StoredProcedure 
cmd.Parameters.AddWithValue("@cid", "1") 
cmd.Parameters("@cid").Direction = ParameterDirection.Input 

cmd.Parameters.AddWithValue("@cname", MySqlDbType.String) 
cmd.Parameters("@cname").Direction = ParameterDirection.Output 
cmd.ExecuteNonQuery() 

Console.WriteLine("City Name: " & cmd.Parameters("@cname").Value) //Access Your Output Value 

让我知道，如果你有任何问题......

感谢