Hey there, that 3464 error is almost always a type mismatch in your SQL string—let's get this sorted quickly!

The Root Cause #

Your Drawingno field in tbl_welddata is almost certainly a text data type, but when you built your SQL query, you didn't wrap the value from Me!CboDrawingno in single quotes. Access tries to interpret that unquoted value as a number, which clashes with the text field, hence the mismatch error.

Quick Fix: Wrap Text Values in Single Quotes #

Update your code to add single quotes around the combo box value:

Dim mydrawing As String
' Add single quotes around the text value to match the field type
mydrawing = "select * from tbl_welddata where [Drawingno] = '" & Me!CboDrawingno & "'"
Me.tbl_welddatasubform.Form.RecordSource = mydrawing
Me.tbl_welddatasubform.Form.Requery

Better Practice: Use Parameter Queries (Avoids SQL Injection & Type Issues) #

For more robustness (and to prevent accidental SQL injection if your combo box allows user input), use a parameterized query instead of string concatenation:

Dim qdf As QueryDef
Dim strSQL As String

' Define SQL with a named parameter
strSQL = "SELECT * FROM tbl_welddata WHERE [Drawingno] = [SelectedDrawing]"

' Create a temporary query definition
Set qdf = CurrentDb.CreateQueryDef("", strSQL)
' Assign the combo box value to the parameter (Access handles type conversion automatically)
qdf.Parameters("[SelectedDrawing]").Value = Me!CboDrawingno

' Set the subform's recordset to the parameterized query results
Set Me.tbl_welddatasubform.Form.Recordset = qdf.OpenRecordset()

' Clean up
Set qdf = Nothing

Quick Checks to Rule Out Other Issues #

• Double-check that your combo box CboDrawingno is returning the correct value: if it's bound to a hidden ID column instead of the Drawingno text, use Me!CboDrawingno.Column(0) (columns are 0-indexed) to get the text value.
• Confirm the data type of Drawingno in tbl_welddata matches the value you're passing (text vs. number).

内容的提问来源于stack exchange，提问作者mak