IF @@ Rowcount = 0 - Access中的SQL语法错误

时间:2011-08-02 13:59:05

标签: sql ms-access syntax

我在excel中有一个子程序,我想将数据写入Access表。我正在尝试更新表中的一行(如果它已经存在),如果不存在则添加它。离开Jeremiah Clark在这个MSDN博客上给出的suggestion,我得知我将从Excel的VBA子程序执行:

UPDATE tblName 
SET  [Column1] = 'text', ...(other values)... [ColumnN] = 1234 

WHERE ([Column1] = 'text' AND [Column2] = 'text2')

If @@ROWCOUNT = 0

INSERT INTO  tblName

VALUES   ( [Column1] = 'text', ...(other values)... [ColumnN] = 1234 )

它给我的错误是:

Syntax error (missing operator) in query expression '([Column1] = 'text' AND [Column2] = 'text2')

If @@ROWCOUNT = 0

INSERT INTO  tblName

VALUES   ( [Column1] = 'text', ...(other values)...'.

我对SQL很陌生,但是如果评估顺序不符合我的预期,我已经尝试了各种方法将IF线包围(括号),但这无济于事。查询的第一部分是否未被评估,因此@@ ROWCOUNT无法正确执行?

Edit1 :如果重要,请使用Access 2003。

解决方案: 基于bluefeet's suggestion(参见他的整个回复):

objDB.Execute sqlStrSelect
recordset.Source = sqlStrSelect
recordset.Open , , adOpenDynamic, adLockOptimistic

If recordset.Fields(0) = 0 Then
  objDB.Execute sqlStrInsert
Else
  objDB.Execute sqlStrUpdate
End If

这依赖于修改后的SELECT查询来获取Access以返回记录的计数:

sqlStrSelect = "SELECT Count(id) FROM table1 WHERE id = 3"

HansUp正确地推测我使用的是ADO连接,因此执行代码必须与bluefeet最初建议的不同。

1 个答案:

答案 0 :(得分:3)

@@ROWCOUNT用于SQL Server而非Access,但由于您使用的是VBA,因此您可以执行与此类似的操作。基本上将您的SQL语句创建为输入您要检查的值的字符串。然后首先针对表运行查询以查看记录是否存在,如果存在则执行UPDATE如果不存在则执行INSERT。我在MS Access 2003中快速测试了它并且它可以工作。

Public Sub test()
    Dim sqlStrUpdate As String
    Dim sqlStrSelect As String
    Dim sqlStrInsert As String
    Dim recordSet As recordSet

    sqlStrUpdate = "UPDATE table1 SET Field1 = " & 5 & " WHERE id = 3"

    sqlStrSelect = "SELECT id FROM table1 WHERE id = 3"

    sqlStrInsert = "INSERT INTO table1 (id, Field1, Field2, Field3) VALUES (3, 5, 0, 0)"

    Set recordSet = CurrentDb.OpenRecordset(sqlStrSelect)

    If recordSet.RecordCount > 0 Then
        DoCmd.RunSQL (sqlStrUpdate)
    ElseIf recordSet.RecordCount = 0 Then
        DoCmd.RunSQL (sqlStrInsert)
    End If

End Sub

编辑:正如HansUp指出您正在使用Excel查询,您的代码可能与此类似:

Public Sub test_new()
Dim cDir_Database         As String
Dim DB_Conn               As New ADODB.Connection         'Access Connection
Dim DB_RSet               As New ADODB.recordSet          'Access Record Set

Dim sqlStrUpdate As String
Dim sqlStrInsert As String

cDir_Database = ".\.\.AccessBD.mdb "

sqlStrUpdate = "UPDATE table1 SET Field1 = " & 10 & " WHERE id = 4"

sqlStrInsert = "INSERT INTO table1 (id, Field1, Field2, Field3) VALUES (4, 5, 0, 0)"

        DB_Conn.ConnectionString = "Driver={Microsoft Access Driver (*.mdb)};" & _
                            "DBQ=" & cDir_Database & ";"
        DB_Conn.Open
        DB_Conn.BeginTrans

        DB_RSet.Open "SELECT id FROM table1 WHERE id = 4", DB_Conn, adOpenStatic, adLockReadOnly

        If DB_RSet.RecordCount > 0 Then
            DB_Conn.Execute (sqlStrUpdate)
        ElseIf DB_RSet.RecordCount = 0 Then
            DB_Conn.Execute (sqlStrInsert)
        End If

        DB_RSet.Close
        DB_Conn.CommitTrans
        DB_Conn.Close

End Sub

这已经从Excel 2003测试到Access 2003并且有效。您需要将引用添加到Microsoft ActiveX数据对象的Excel文件中。