问题描述
Imports System.Data.SqlClient
Public Class ProdA
Dim com As New SqlConnection
Dim cmd As SqlCommand
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Try
com.ConnectionString = "Data Source=" + Production.TextBox3.Text + ";Database=Database1;User Id=" + Production.TextBox1.Text + ";Password=" + Production.TextBox2.Text + ";"
com.Open()
这是我使用与SQL SERVER建立连接的过程.我的数据库有一个名为STOCKS_Details的表,其列为fact1/fact2/fact3/total/DATE.因此,要进行计算,我需要将前一行DATE放入VB应用程序的变量中.问题是如何编写查询以将值检索到变量..
谢谢您
This is the procedure i''m using build the connection with my SQL SERVER. my DB has table called STOCKS_Details whose columns are fact1/fact2/fact3/total/DATE.So to do calculations i need to pick previous row DATE into a variable on a VB application. The Problem is how can I write the Query to retrieve value to the variable..
THANK YOU
推荐答案
select max(@@IDENTITY) from Images
2.如果您的表没有身份,则需要创建过程
2. If ur table doesn''t have identity u need to create procedure
Create Procedure Get_LastRow
(
@Tname Varchar(50)
)
AS
BEGIN
EXECUTE ('DECLARE GETLAST CURSOR DYNAMIC FOR SELECT * FROM ' + @Tname)
--select date from the above query
OPEN GETLAST
FETCH LAST FROM GETLAST
CLOSE GETLAST
DEALLOCATE GETLAST
END
并执行该过程以获得类似
的结果
and execute that procedure to get the result like
EXEC Get_LastRow 'dbo.TableName'
如果有帮助,请接受解决方案!
谢谢
〜JK
Accept the solution if this is helpful!!
Thanx
~JK
select * from tbl timestampCol=max(timestampCol)
2.最后添加 条记录,
2. for lastly added record,
--Insert statement then
select @@Identity
祝您编码愉快!
:)
Happy Coding!
:)
Select top 1 fact1,fact2,fact3,total,date from stock_details order by date desc.
现在将此查询编写为sqlcommand并将输出填充到数据表中.
然后获取每个数据表列的值并将其设置为变量.
我正在用C#编写示例代码.
Now write this query as sqlcommand and fill the output in datatable.
Then get value for each datatable column and set it to your variable.
i am writing sample code in c#.
foreach(DataRow dr in datatable)
{
int fact1=Convert.ToInt32(dr["fact1"].ToString());
}
在VB中
in VB
For Each dr As DataRow In datatable
Dim fact1 As Integer = Convert.ToInt32(dr("fact1").ToString())
Next
更新了解决方案.
如果只需要最大日期"列,请尝试此
Updated solution.
If you need only max date column, then try this
Select max(Date) from stock_detail
s
然后
s
Then
Dim dt as datetime
dt=Convert.ToDateTime(cmd.ExecuteS
calar());
calar());
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