Global Variables in SQL statement

问题

I have the following code in VBA:

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

newvalue and tempvalue are both global variables and have already been set values. Syntax wise, does this make sense? or am I missing quotation marks?

回答1:

Try this one:

If MID is number:

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

If MID is string (if newvalue/tempvalue doesn't contain single quote '):

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

If MID is string (if newvalue/tempvalue contains single quote ' like newvalue="Mike's car"):

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

If MID is date:

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

Thanks to @HansUp for pointing out in comments, that

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]

来源：https://stackoverflow.com/questions/22563844/global-variables-in-sql-statement