How Can I Update a Field in Microsoft Access Using the Result of a SELECT Query?

Using SELECT within UPDATE Queries: A Workaround for Microsoft Access

While UPDATE queries in Microsoft Access 2007 offer a straightforward way to modify table data, they lack the ability to incorporate results from SELECT queries. This limitation can be frustrating when attempting to update fields using complex selection criteria.

Consider the following scenario: you want to update the "Func_TaxRef" field in the "FUNCTIONS" table based on a minimum value from a "TAX" table. The following SELECT query returns the desired minimum value:

SELECT Min(TAX.Tax_Code) AS MinOfTax_Code
FROM TAX, FUNCTIONS
WHERE (((FUNCTIONS.Func_Pure)<=[Tax_ToPrice]) AND ((FUNCTIONS.Func_Year)=[Tax_Year]))
GROUP BY FUNCTIONS.Func_ID;

However, the following UPDATE query fails to update the "Func_TaxRef" field with the result of the SELECT query:

UPDATE FUNCTIONS
SET FUNCTIONS.Func_TaxRef = [Result of Select query]

To overcome this limitation, we must employ a workaround by creating a temporary table that stores the results of the SELECT query. This is achieved through the following steps:

1. Create a SELECT query: Create a query that calculates the minimum tax code for each function. Save it as "YourQuery."
2. Convert the query into a table: Use a Make Table query to store the results of "YourQuery" into a new table called "MinOfTax_Code."
3. Update using multiple tables: Perform an UPDATE query that joins the "MinOfTax_Code" table with the "FUNCTIONS" table and updates the "Func_TaxRef" field with the minimum tax code.

UPDATE MinOfTax_Code 
INNER JOIN Functions ON MinOfTax_Code.func_id = Functions.Func_ID 
SET Functions.Func_TaxRef = [MinOfTax_Code].[MinOfTax_Code]

While this workaround may seem convoluted, it effectively allows you to update fields using the results of a SELECT query in Microsoft Access 2007. However, it's worth considering the limitations of Access and exploring alternative database solutions for more complex data manipulation tasks.

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