An SQL expression is a string that makes up all or part of an SQL statement. For example, theFindFirst method on a Recordset object uses an SQL expression consisting of the selection criteria found in an SQL WHERE clause.
The Microsoft Access database engine uses the Microsoft® Visual Basic® for Applications (or VBA) expression service to perform simple arithmetic and function evaluation. All of the operators used in Microsoft Access database engine SQL expressions (except Between, In, and Like) are defined by the VBA expression service. In addition, the VBA expression service offers over 100 VBA functions that you can use in SQL expressions. For example, you can use these VBA functions to compose an SQL query in the Microsoft Access query Design view, and you can also use these functions in an SQL query in the DAO OpenRecordset method in Microsoft Visual C++®, Microsoft Visual Basic, and Microsoft Excel code.