ACC2000: How to Return Case-Sensitive Matches in Queries

You can use the Asc() function or the StrComp() function to have Microsoft Access differentiate between case-sensitive text strings. When you use the Asc() function in a select query, Access can locate an exact, case-sensitive match using the first letter of a text string. The StrComp() function can perform a case-sensitive match for the whole string.

Both of these functions can be useful in checking for names in a database that are supposed to be uppercase or proper case, but which have been entered incorrectly.

To find all the records in a field that contain lowercase text rather than uppercase text for the first character, use either of the following methods.

Method 1: Find Text With an Initial Lowercase Letter Using the Asc() Function

1. Start Microsoft Access, and then create a new blank database.
2. Create a new table with the following field:
   Field Name: FirstName
   Data Type: Text
   Field Size: 50
   
   Field Name: LastName
   Data Type: Text
   Field Size: 50
   Save the table as tblNameList. When you are prompted to create a key field, click No.
3. Add the following records to the tblNameList table:

      FirstName     LastName
      ---------     ----------
      Andrew        Maclean
      Nancy         Macleod
      Zareda        van Helsing
      andrew        MacLean
      nancy         MacLeod
      zareda        Van Helsing
   					

4. Create a new query based on the tblNameList table, and then enter the following data in the query grid:
   Field: FirstName
   Table: tblNameList
   Show: True
   
   Field: LastName
   Table: tblNameList
   Show: True
   
   Field: Asc([FirstName])
   Show: False
   Criteria: >=Asc("a") And <=Asc("z")
5. Run the query. Note that you have selected only the records that contain first names with an initial lowercase letter.

Method 2: Find Text With a Lowercase Letter in Any Position Using the StrComp() Function

1. If you have not already done so, create the test database using steps 1 through 3 in Method 1.
2. Create a new query based on the tblNameList table, and then enter the following data in the query grid:
   Field: StrComp([FirstName],"a",0)
   Show: False
   Criteria: 1
   
   Field: FirstName
   Table: tblNameList
   Show: True
   
   Field: LastName
   Table: tblNameList
   Show: True
   
3. Run the query. Note that the query returns the same results as in Method 1.
4. Open the query in Design View, and then change the Field parameters in the first column of the query grid to:
   Field: StrComp([LastName],"Mack",0)
   Run the query. Note that the query returns "Maclean" and "Macleod," but not "MacLean" and "MacLeod." The records for "van Helsing" are also selected because the criteria you entered for the StrComp() function returns any binary values that are greater than the search criteria "Mack."

For more information about the Asc() function, in the Visual Basic Editor, click Microsoft Visual Basic Help on the Help menu, type asc function in the Office Assistant or the Answer Wizard, and then click Search to view the topic.

For more information about the StrComp() function, in the Visual Basic Editor, click Microsoft Visual Basic Help on the Help menu, type strcomp function in the Office Assistant or the Answer Wizard, and then click Search to view the topic.