C#和SQL更新查询 [英] C# and SQL update query

问题描述

我有这段代码应该更新数据库中表中的一行.
如果我直接在SQL Server中将其作为查询编写，则该查询有效，但在C#上下文中则无效.有人可以给我解释一下我应该怎么做才能完成这项工作:

这是我的代码:

I have this code that should update a row in a table from a database.
The query works if I write it in SQL server directly as a query, but it doesn''t work from a C# context. Can somebody please explain me what I should do to make this work:

this is my code:

//Pas huidig saldo kassa aan:
        public void huidigSaldoKassaAanpasser(int kassaID, double bedrag)
        {

            SqlTransaction transactie = null;
            try
            {
                if (connectie.State == System.Data.ConnectionState.Closed)
                {
                    connectie.Open();
                }
                transactie = connectie.BeginTransaction();
                SqlCommand cmdHaalGegevensOp = new SqlCommand(@"Update Kassa SET huidigsaldo = @bedrag
                                                                      WHERE id = @kassaID");
                cmdHaalGegevensOp.Connection = connectie;
                cmdHaalGegevensOp.Transaction = transactie;
                cmdHaalGegevensOp.Parameters.AddWithValue("@kassaID", kassaID);
                cmdHaalGegevensOp.Parameters.AddWithValue("@bedrag", bedrag);
                cmdHaalGegevensOp.ExecuteNonQuery();
               
            }
            catch (Exception ex)
            {
                if (transactie != null)
                {
                    transactie.Rollback();
                }
                throw ex;
            }
            finally
            {
                connectie.Close();
            }
        }

不幸的是，每次我运行这段代码时，我都没有异常，但是该行没有更新. int kassaID和double bedrag是正确的.

如果我在SQL Server Management Studio中将其作为新查询编写为:

更新Kassa SET huidigsaldo = 598 WHERE ID = 7;

一切正常.

Unfortianetly everytime i run this code, I get no exceptions but the row isn''t updated. The int kassaID and the double bedrag are correct.

If I write it as this in SQL server management studio as a new Query:

Update Kassa SET huidigsaldo = 598 WHERE id = 7;

everything works fine.

推荐答案

它永远不会更新，因为您没有提交事务-您只需关闭它即可.在ExecuteNoQuery调用之后，添加以下行:

It is never updated because you do not Commit the transaction - you just close it. After the ExecuteNoQuery call, add the line:

transactie.Commit();

能否告诉我数据库中"huidigsaldo"字段的类型，如果它是int，添加时必须将参数"bedrag"转换为in，请参见下面的代码

can you tell me the type of "huidigsaldo" field in the database, if it is an int, you have to convert parameter "bedrag" to in when you are adding , see code as below

cmdHaalGegevensOp.Parameters.AddWithValue("@bedrag",Convert.ToInt32(bedrag));

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