执行删除语句但不从数据库中删除数据 [英] Delete statement executes but Data is not deleted from Database

问题描述

Hello Experts，



我有一个Windows窗体应用程序。我正在使用我的DB2数据库连接，这是我的代码。代码执行没有任何错误。但是当我在数据库中看到时，我仍然可以看到声称被删除的记录。意思是它没有删除。

Hello Experts,

I have a windows Forms application. I am using my DB2 Database connection and Here is my code. Code executes without any error. But when I see in Database I can still see the record which is claimed to be deleted. Meaning it is not deleted.

Dim cm As New iDB2Command
   Dim da As New iDB2DataAdapter

 cm = dbclass.getCommand("Delete from TESTDATA.VXWFEATURE  where I001TRLN=@Tireline and FECLS=@selClass")
         cm.Parameters.Add("@Tireline", iDB2DbType.iDB2VarChar).Value = Tireline
         cm.Parameters.Add("@selClass", iDB2DbType.iDB2Decimal).Value = selClass


Using cn As iDB2Connection = cm.Connection
       cn.Open()
       cm.ExecuteNonQuery()
       success = True
     End Using

有人可以帮帮我吗？

Can anyone help me with this please?

推荐答案

有两个可能的原因：



1）您提供给WHERE子句的值实际上并不匹配任何记录。 />


2）DB2可能需要提交显式事务才能不回滚DELETE语句。我实际上不知道是不是这种情况 - 但在任何情况下使用明确的交易都是好的做法。



不直接相关：你的方式使用连接相当奇怪。



这应该工作或接近工作（我无法测试）：

There are two potential causes:

1) The values you're supplying to the WHERE-clause don't actually match any record.

2) DB2 may require an explicit transaction to be committed in order to not roll back your DELETE-statement. I actually don't know if this is the case or not - but it's good practice in any case to use an explicit transaction.

Not directly related: Your way of "using" the connection is rather strange.

This should work or be "close to working" (I can't test it):

Public Sub Example(connectionString As String) ' add Tireline and selClass as arguments
    Using connection As DB2Connection = New DB2Connection(connectionString)
    Using transaction As DB2Transaction = connection.BeginTransaction(IsolationLevel.Serializable)
    Using command As DB2Command = New DB2Command("", connection, transaction)
		
    connection.Open()

    command.CommandText = "DELETE FROM TESTDATA.VXWFEATURE WHERE I001TRLN=@Tireline AND FECLS=@selClass"
    command.Parameters.Add("@Tireline", iDB2DbType.iDB2VarChar).Value = Tireline
    command.Parameters.Add("@selClass", iDB2DbType.iDB2Decimal).Value = selClass
    command.ExecuteNonQuery()
		
    transaction.Commit()

    End Using
    End Using
    End Using
End Sub

如果你不能把它编译好，请告诉我，我会尽力帮忙。

If you can't get this to compile, please tell and I'll try to help.

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