[英]ExecuteNonQuery and Return Value from SQL Server, C#
我想为用户提供Web服务,以便用户在表中插入或更新某些值。 用户输入一个ID和三个参数。 如果该ID在数据库中不存在,我想返回0,则失败或类似。 当我测试下面的代码并提供一个不存在的ID时,存储过程返回1的单元格(返回值)为0,但状态设置为1。我猜这是因为我在执行查询时使用ToString()并返回1个单元格。 那么我应该如何改进下面的代码?
我在方法中有此代码:
string status = "";
SqlParameter[] param = {
new SqlParameter("@ID", ID),
new SqlParameter("@Flag", Flag),
new SqlParameter("@C_Interval", C_Interval),
new SqlParameter("@D_Interval", D_Interval)
};
status = DatabaseHelper.ExecuteNonQuery("sp_InsertInstruction", param);
return status;
在ExecuteNonQuery中,我将存储过程命令传递给数据库
// skipped some of the code this example
status = cmd.ExecuteNonQuery().ToString();
return status;
我的存储过程如下所示:
ALTER PROCEDURE dbo.sp_InsertInstruction
@Flag char(1) = null,
@C_Interval int=null,
@D_Interval int=null,
@ID char(20),
AS
DECLARE @Entity_ID int
SET @Entity_ID = (SELECT ID FROM Entity WHERE ID = @ID)
INSERT INTO Instructions(Flag, C_Interval, D_Interval, Entity_ID)
VALUES (@Flag, @C_Interval, @D_Interval, @Entity_ID)
提前致谢。
ExecuteNonQuery返回受影响的行数。 在这种情况下,您总是要插入一行。
更改您的SP以读取如下内容:
ALTER PROCEDURE dbo.sp_InsertInstruction
@Flag char(1) = null,
@C_Interval int=null,
@D_Interval int=null,
@ID char(20),
AS
DECLARE @Entity_ID int
SET @Entity_ID = (SELECT ID FROM Entity WHERE ID = @ID)
IF (@Entity_ID IS NOT NULL)
BEGIN
INSERT INTO Instructions(Flag, C_Interval, D_Interval, Entity_ID)
VALUES (@Flag, @C_Interval, @D_Interval, @Entity_ID)
END
即只有在实体ID确实存在时才插入。
将此代码放在存储过程的顶部
ALTER PROCEDURE dbo.sp_InsertInstruction
@Flag char(1) = null,
@C_Interval int=null,
@D_Interval int=null,
@ID char(20),
AS
IF NOT EXISTS
(
SELECT ID
FROM Entity
WHERE ID = @ID
)
BEGIN
RETURN 0;
END
-- Your remaining SQL Code here....
被显示为“ 1”的返回值是执行查询后返回的总行数。
这是您可能需要做的事情的草稿,这只是关于如何在代码中处理过程数据的想法。 而且我正在修改您的sql过程以返回您期望返回的值。
对于后面的代码:
using System.Data.SqlClient;
using System.Data;
public class DBAccess{
private string strCon = "Data Source=YourServer;Initial Catalog=YourDBName;etc";
public string GetResult(){
string strQuery = "Exec YourProcedure Param1";
SqlCommand cmdSql = new SqlCommand(strQuery);
SqlConnection conSql = new SqlConnection(strCon);
conSql.Open();
cmdSql.Connection=conSql;
SqlDataReader dreSql = cmdSql.ExecuteReader();
dreSql.Read();
// here I'm trying to read the item of the row on the column named Result
return dreSql["Result"].ToString();
}
}
您的程序:
ALTER PROCEDURE dbo.sp_InsertInstruction
@Flag char(1) = null,
@C_Interval int=null,
@D_Interval int=null,
@ID char(20) AS
DECLARE @Entity_ID int
SET @Entity_ID = (SELECT ID FROM Entity WHERE ID = @ID)
if(@Entity_ID is not null)
begin
INSERT INTO Instructions(Flag, C_Interval, D_Interval, Entity_ID)
VALUES (@Flag, @C_Interval, @D_Interval, @Entity_ID)
-- this will return as a table with the result of 1
select Result='1'
end
else
begin
-- this will return as a table with the result of 0
select Result='0'
end
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