sql - SQL 语句中的全局变量

Question

我在 VBA 中有以下代码:

Dim strSQL As String
strSQL = "UPDATE Workstations SET MID = newvalue WHERE MID = tempvalue"
DoCmd.RunSQL strSQL

newvalue 和 tempvalue 都是全局变量，并且已经设置了值。语法明智，这有意义吗？还是我缺少引号？

Answer 1

试试这个:

如果MID是数字:

Dim strSQL As String
strSQL = "UPDATE Workstations SET [MID] = " & newvalue & " WHERE [MID] = " & tempvalue
DoCmd.RunSQL strSQL

如果 MID 是 string(如果 newvalue/tempvalue 不包含单引号 ' ):

Dim strSQL As String
strSQL = "UPDATE Workstations SET [MID] = '" & newvalue & "' WHERE [MID] = '" & tempvalue & "'"
DoCmd.RunSQL strSQL

如果 MID 是 string(如果 newvalue/tempvalue 包含单引号 ' 喜欢 newvalue="Mike's car"):

Dim strSQL As String
strSQL = "UPDATE Workstations SET [MID] = '" & Replace(newvalue, "'", "''") & "' WHERE [MID] = '" & Replace(tempvalue, "'", "''") & "'"
DoCmd.RunSQL strSQL

如果 MID 是 日期:

Dim strSQL As String
strSQL = "UPDATE Workstations SET [MID] = #" & newvalue & "# WHERE [MID] = #" & tempvalue & "#"
DoCmd.RunSQL strSQL

感谢@HansUp 在评论中指出，

MID is the name of a function, so it would be safer to bracket or alias that field name in the SQL statement: SET [MID]