error 3075 syntax missing comma - sql

Question

I've looked in many places on the internet trying to solve this problem but I can't seem to figure it out. Could someone just provide a second set of eyes and just check where I may have gone wrong with the syntax?
The error says RunTime error 3075,
"Syntax error (comma) in query expression
'('test',12/15/2014','Primary')'.
Originally it worked when I had this split into four different INSERT statements, but when I combined it, it stopped working
SQL = "INSERT INTO WeeksonCall([Employee], [Week], [Prim/Backup]) VALUES (('" & _ cboName.Column(1) & "','" & cboWeek.Column(1) & "','" & cboPrimBack.Value & _
"'),('" & cboName2.Column(1) & "','" & cboWeek.Column(1) & "','" & cboPrimBack2.Value & _
"'),('" & cboName.Column(1) & "','" & cboWeek2.Column(1) & "','" & cboPrimBack2.Value & _
"'),('" & cboName2.Column(1) & "','" & cboWeek2.Column(1) & "','" & cboPrimBack.Value & "'))"

Answer 1

That is not proper syntax in MS Access. You will have to insert the records individually like:
DoCmd.SetWarnings False
SQL = "INSERT INTO WeeksonCall(Employee, Week, [Prim/Backup]) " & _
"VALUES ('" & _ cboName.Column(1) & "','" & cboWeek.Column(1) & "','" & cboPrimBack.Value & "')"
SQL = "INSERT INTO WeeksonCall(Employee, Week, [Prim/Backup]) " & _
"VALUES ('" & cboName2.Column(1) & "','" & cboWeek.Column(1) & "','" & cboPrimBack2.Value & "')"
SQL = "INSERT INTO WeeksonCall(Employee, Week, [Prim/Backup]) " & _
"VALUES ('" & cboName.Column(1) & "','" & cboWeek2.Column(1) & "','" & cboPrimBack2.Value & "')"
SQL = "INSERT INTO WeeksonCall(Employee, Week, [Prim/Backup]) " & _
"VALUES ('" & cboName2.Column(1) & "','" & cboWeek2.Column(1) & "','" & cboPrimBack.Value & "')"
DoCmd.SetWarnings True
EDIT: You can stop the user prompts by using SetWarnings = False before the inserts. Then turn the warnings back on after the inserts via DoCmd.SetWarnings True.

Answer 2

Can you please provide the remainder of the VBA you're using in order to ask the user for input? As far as I see you're only assigning a string to the SQL variable. Where is the rest of your code?
And, by the way, I never like using:
DoCmd.SetWarnings False
Instead use the module below, that way if you do get an error you can deal with it instead of hidding it:
Option Compare Database
Option Explicit
Public Function Run_Safe_SQL(strSQL)
On Error GoTo Error_Handler
Dim db As DAO.Database
Set db = CurrentDb()
db.Execute strSQL, dbFailOnError
DBEngine.Idle dbRefreshCache
' DoEvents
Exit_Here:
'Cleanup
Set db = Nothing
strSQL = ""
Exit Function
Error_Handler:
MsgBox Err.Description & " " & Err.Number
End Function