Question

我一直在尝试使用ADODB.Command执行参数化查询。我知道我可以用“？”对于参数，但我的查询相当大，我真的不想跟踪参数的确切顺序。我试过以下的东西：

objCmd.CommandType = adCmdText
objCmd.CommandText = "SELECT ... WHERE field1=@p_Field1 ...."    
Dim objParam As ADODB.Parameter
Set objParam = objCmd.CreateParameter("@p_Field1" ...)
objCmd.Parameters.Append objParam
...
objCmd.Open

它适用于存储过程参数（显然设置CommandType = adCmdStoredProc），但由于查询本身的动态特性，我无法在存储过程中执行此操作。当我尝试运行查询时，我收到错误：

 Must declare the scalar variable "@p_Field1"

还有其他方法不涉及使用存储过程或（argh）连接查询本身的参数值而根本不使用参数吗？

Answer 1

您可以执行此操作，以允许您重复使用参数

objCmd.CommandText = "declare @var1 int, @var2 int, @var3 int; " & _
    "select @var1 = ?, @var2 = ?, @var3 = ?;" & _
    "select ... where field1 = @var1 or field4 = @var1 or field2 = @var2 ... "

并以正常的有序方式添加参数。

Answer 2

所以看起来ADODB.Command并不真正支持命名参数。

Answer 3

自从我使用VB6以来已经有一段时间了，但您是否尝试将Command对象上的NamedParameters属性设置为True？

即

objCmd.NamedParameters = True

Answer 4

我知道如何做到这一点的唯一方法就是创造？作为参数，例如

在你的例子中：

objCmd.CommandText = "SELECT ... WHERE field1=@p_Field1 ...."

将其更改为：

objCmd.CommandText = "SELECT ... WHERE field1 = ?"    
objCmd.NamedParameters = True
Dim objParam As ADODB.Parameter
Set objParam = objCmd.CreateParameter("@AnyName",,,,Value)
objCmd.Parameters.Append objParam

希望这有帮助

Answer 5

它并不完美，但是......这是我创建的包装类，允许您创建命名参数查询......

此代码下方是演示。现在最大的问题是你必须按照声明的正确顺序执行你的setParameter语句。

Class SQLBuilder

Private Sub Class_Initialize(  )
    Set internal_commandObject = Server.CreateObject("ADODB.Command")
End Sub

Private internal_sql
Private internal_parameters
private internal_commandObject

Public Property Let CommandType(ByVal value)
    internal_commandObject.CommandType = value
End Property

Public Property Get CommandType
    CommandType = internal_commandObject.CommandType
End Property

Public Property Let Prepared(ByVal value)
    internal_commandObject.Prepared = value
End Property

Public Property Get Prepared
    Prepared = internal_commandObject.Prepared
End Property

Public Property Get SQLCommandObject
Set SQLCommandObject = internal_commandObject
End Property

Public Property Let SQLCommandObject(ByVal value)
Set internal_commandObject = value
End Property

Public Property Get CommandText
    CommandText = internal_commandObject.CommandText
End Property

Public Property Let CommandText(ByVal sqlStatement)
    GetSQLParameters sqlStatement
    internal_commandObject.CommandText =  internal_sql
End Property

Public Property Get Parameters
    Set Parameters = internal_parameters
End Property


Public Function SetParameter(name,datatype,direction,size,value)

 internal_commandObject.Parameters.Append internal_commandObject.CreateParameter(name,datatype,direction,size,value)
End Function 

Private Sub GetSQLParameters(sql)
    internal_commandObject.NamedParameters = true
    Set RegExObj = New RegExp

    With RegExObj
        .Global = true
        .Multiline = true
        .Pattern = "@\S+"
        .IgnoreCase = true
    End With

    Set internal_parameters =  CreateObject("Scripting.Dictionary")

    With internal_parameters
        For each item in RegExObj.Execute(sql) 
        if Not .Exists(item.value) then  
            .Add item.value,item.value
        end if
        Next

    End With
    internal_sql = RegExObj.Replace(sql,"?")
End Sub


End Class

    Dim Temp
Dim mySqlBuilder 
Set mySqlBuilder = new SQLBuilder

With mySqlBuilder
    set .SQLCommandObject.ActiveConnection =PropConnection
.CommandText = "select LegalDescription from STAGE.DataLegalDescription where FISCAL_YEAR = @FISCAL_YEAR AND  AccountNumber = @ACCOUNT_NUMBER"
.Prepared = true
.SetParameter "@FISCAL_YEAR",adInteger,adParamInput,4, Cint(Year)
.SetParameter "@ACCOUNT_NUMBER",adVarChar,adParamInput,13, AccountNumber
End With

    RSProp.Open mySqlBuilder.SQLCommandObject

VB6 + SQL-Server：如何使用ADODB.Command执行带有命名参数的查询？

5 个答案:

此代码下方是演示。现在最大的问题是你必须按照声明的正确顺序执行你的setParameter语句。