创建一个表单以根据多个条件搜索记录

Question

我正在尝试创建一个允许您return 基于多个条件的结果的表单。

我有 FirstName 字段、LastName 字段和 State 字段。

我还有一个名为 searchFirst、searchLast、searchState 的文本框，用户可以在其中输入条件。

点击搜索按钮后会执行以下代码。

Private Sub mySearchQuery_Click()

Dim filter As String

Dim rtFirstName As String
Dim rtLastName As String
Dim rtState As String

rtFirstName = Me.searchFirst.Value
rtLastName = Me.searchLast.Value
rtState = Me.searchState.Value

If Not IsNull(rtFirstName) Then
        If Not IsNull(filter) Then filter = filter & " AND "
        filter = filter & "(FirstName like""*" & rtFirstName & "*"")"
End If


If Not IsNull(rtLastName) Then
        If Not IsNull(filter) Then filter = filter & " AND "
        filter = filter & "(LastName like""*" & rtLastName & "*"")"
End If

If Not IsNull(rtState) Then
        If Not IsNull(filter) Then filter = filter & " AND "
        filter = filter & "(State LIKE""*" & rtState & "*"")"
End If

' Now re-construct the SQL query '
Dim sql As String
sql = "SELECT * FROM MainData"

If Not IsNull(filter) Then
        sql = sql & " WHERE " & filter
End If

Me.RecordSource = sql
'SubForm.Form.RecordSource = sql

End Sub

我在下面收到以下错误。

Run-time error '3075': Syntax error (missing operator) in query expression 'AND (FirstName like"*tracy*") AND (lastName like"*Smith*") AND (State LIKE"*ga*")'.

我不确定为什么 AND 包含在搜索查询的开头？

Answer 1

I am not sure why AND was included at the beginning of the search query?

因为你有 Dim filter As String，filter 永远不能包含 Null。这意味着这些 If 条件... If Not IsNull(filter) ... 将永远为真。

同样，Not IsNull(rtFirstName)、Not IsNull(rtLastName) 和 Not IsNull(rtState) 将始终为 True。

最终结果是代码向您的 filter 字符串添加了另一个条件片段，无论相应的搜索文本框是否包含任何内容，并且每个片段都以 " AND " 为前缀。

考虑到这些要点，您可以重构代码，仅当相应的搜索文本框中有内容时才添加 filter 段，并决定何时包含 " AND "。然而，我发现为它们中的每一个都包含 " AND " 然后在将它添加到 WHERE 子句之前从 filter 中删除第一个 " AND " 更简单。

Private Sub mySearchQuery_Click()
    Dim strSelect As String
    Dim strWhere As String

    If Len(Trim(Me!searchFirst.Value) & vbNullString) > 0 Then
        strWhere = strWhere & " AND FirstName Like ""*" & Me!searchFirst.Value & "*"""
    End If

    If Len(Trim(Me!searchLast.Value) & vbNullString) > 0 Then
        strWhere = strWhere & " AND LastName Like ""*" & Me!searchLast.Value & "*"""
    End If

    If Len(Trim(Me!searchState.Value) & vbNullString) > 0 Then
        strWhere = strWhere & " AND State Like ""*" & Me!searchState.Value & "*"""
    End If

    ' Now re-construct the SQL query
    strSelect = "SELECT * FROM MainData"

    ' only add WHERE clause if we have something in strWhere    
    If Len(strWhere) > 0 Then
        ' use Mid() to ignore leading " AND "
        strSelect = strSelect & " WHERE " & Mid(strWhere, 6)
    End If
    Debug.Print strSelect ' <- inspect this in Immediate window; Ctrl+g will take you there

    ' enable one of these RecordSource lines after confirming Debug.Print shows you what you need
    'Me.RecordSource = sql
    'SubForm.Form.RecordSource = sql
End Sub

创建一个表单以根据多个条件搜索记录

Creating a form to search for records based on multiple criteria

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