How Can I Concatenate Rows in Microsoft Access Using a Query?

Using Microsoft Access Queries to Combine Rows

Microsoft Access provides a straightforward method for merging rows with shared values in a column using queries. This is particularly useful when you need to consolidate data based on a common field. Let's illustrate this with a practical example using two columns.

Imagine a table structured as follows:

<code>ColumnA | ColumnB
--------|--------
1       | abc
1       | pqr
1       | xyz
2       | efg
2       | hij
3       | asd</code>

The goal is to combine the entries in 'ColumnB' into a single cell for each unique 'ColumnA' value. The desired outcome is:

<code>ColumnA | ColumnB
--------|--------
1       | abc, pqr, xyz
2       | efg, hij
3       | asd</code>

Here's how to achieve this using a query in Access:

1. Create a New Query: Navigate to the "Create" tab and select "Query Design."

2. Add Your Table: Add the table containing the data you wish to concatenate.

3. Select Columns: Choose 'ColumnA' for grouping and 'ColumnB' for concatenation.

4. Build the Concatenation Expression: Add a new field to the query grid. In the field's "Expression" property, enter the following formula:

   <code class="language-sql">GetList("SELECT ColumnB FROM YourTableName WHERE ColumnA = " & [ColumnA],"",", ")</code>

   Remember to replace "YourTableName" with the actual name of your table.

5. Execute and Save: Save the query and run it to view the concatenated results. The query will now display the combined 'ColumnB' values for each unique 'ColumnA' value.

This method effectively uses the GetList function to perform the concatenation within the Access query, providing a clean and efficient solution for consolidating row data.

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