Update Null Fields with SQL in MS Access

问题

I'm trying to run some SQL commands in Access VBA to update the blank (null) fields in a column with the value obtained from a combobox in the form.

At the moment I'm receiving

Run time Error '3061' Too Few Parameters. Expected 1

but it appears to be properly formed.

The code I'm using is below. User will be passed as a string, e.g. - "Joe Bloggs".

Public Sub testSub(user as string)
Dim db as DAO.Database
Dim sqlstr as String
set db as CurrentDB

sqlstr = "UPDATE tTable1 SET Field1 = [" & user & "] WHERE Field1 IS NULL;"

db.Execute sqlstr

End Sub

回答1:

I think you need to have user as a 'string' in your query using single quotes. Also, I have always used set db = currentdb instead of using as

Public Sub testSub(user as string)
Dim db as DAO.Database
Dim sqlstr as String
set db = CurrentDB

sqlstr = "UPDATE tTable1 SET Field1 = '" & user & "' WHERE Field1 IS NULL;"

db.Execute sqlstr

End Sub

EDIT: As @jarlh has mentioned I agree, I don't think that the square parentheses are required

回答2:

Consider a parameter query instead of concatenating a quoted string value into your UPDATE statement text. You don't need those quotes when using the parameter approach, and that also safeguards you from the issue Alex warned about (when the user string itself contains an apostrophe).

Public Sub testSub(ByVal pUser As String)
    Dim db As DAO.Database
    Dim qdf As DAO.QueryDef
    Dim sqlstr As String

    sqlstr = "UPDATE tTable1 SET Field1 = [which_user] WHERE Field1 IS NULL;"
    Set db = CurrentDb
    Set qdf = db.CreateQueryDef(vbNullString, sqlstr)
    qdf.Parameters("which_user").Value = pUser
    qdf.Execute sqlstr, dbFailOnError
End Sub

来源：https://stackoverflow.com/questions/36453949/update-null-fields-with-sql-in-ms-access