Question

需要一些SQL建议

我正在使用一个名为WinCC的程序，其中我使用的是Vb脚本语言和SQL。

我有一个SQL表，其中有3列，TagName，Value和Date

我需要为所选月份中的每一天显示每个TagName的值。

以下SQL查询为我每月的每一天提供相同的值。当我在这个月的每一天都有不同的价值观时。

Tags(0) = "Tag1"
Tags(1) = "Tag2"

TempTags(0) = "Temp1"
TempTags(1) = "Temp2"

  ConnectionString = "Provider=SQL Native Client;Server=WIN81   \WINCC;Database=Teams;Trusted_Connection=yes"        

 Set Connection = CreateObject("ADODB.Connection")
 Set rs = CreateObject ("ADODB.Recordset")     
 Connection.ConnectionString = ConnectionString
 Connection.Open  

For i = 0 To 2

    SQLStr = "select Value FROM atrperformancestats WHERE TagName =   '"+Tags(i)+"'And Month(Date)='"+date+"'"   
     rs = Connection.Execute(SQLStr)   
     HMIRuntime.Tags(TempTags(i)).Write rs("Value")             

Next

我已经尝试更改我的SQL查询以获取用户选定月份中每天的值，但我失败了......请帮忙

非常感谢

Answer 1

如果查询返回多行，则需要While循环来处理结果集。下面是一个参数化示例，假设date是表示月份的整数。

Const adVarChar = 200
Const adInteger = 3
Const adParamInput = 1
Const adCmdText = 1

Tags(0) = "Tag1"
Tags(1) = "Tag2"

TempTags(0) = "Temp1"
TempTags(1) = "Temp2"

ConnectionString = "Provider=SQL Native Client;Server=WIN81   \WINCC;Database=Teams;Trusted_Connection=yes"        

Set Connection = CreateObject("ADODB.Connection")
Set Command = CreateObject("ADODB.Command")
Connection.ConnectionString = ConnectionString
Connection.Open  

Command.ActiveConnection = Connection
Command.CommandType = adCmdText

Command.CommandText = "SELECT Value FROM atrperformancestats WHERE TagName = ? And Month(Date) = ?;"   

Set parmTagName = command.CreateParameter("TagName", adVarchar, adParamInput, 100)
Command.Parameters.Append(parmTagName)
Set parmDate = command.CreateParameter("Date", adInteger, adParamInput)
command.Parameters.Append(parmDate)

For i = 0 To 1

    parmTagName.Value = Tags(i)
    parmDate.Value = date
    Set rs = Command.Execute()
    While rs.EOF = False
        HMIRuntime.Tags(TempTags(i)).Write rs("Value").Value             
        rs.MoveNext
    WEnd

    rs.Close

Next

Answer 2

在WinCC中，SCADA程序不是很苛刻，我最终找到了一种方法......

        j = 0
        SQLStr = "Select Value FROM table1 WHERE Name =  '" + Names(i) + "' And Month(Date) = '" + MonthSelect + "' order by date asc"                      
        rs.Open SQLStr, Connection                          
        Do Until j = 31                         
            HMIRuntime.Tags(arrayInt(i)).Write rs("Value")              
            rs.MoveNext     
            i = i +1
            j = j +1
        Loop

它有效!!!

感谢所有的帮助，你对循环的推荐让我思考

Sql命令混乱

2 个答案: