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How Can I Concatenate MySQL Columns to Create Unique Alphanumeric Identifiers?

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2025-01-04 17:06:45505browse

How Can I Concatenate MySQL Columns to Create Unique Alphanumeric Identifiers?

Concatenation of MySQL Table Columns for Unique Number Generation

Consider a MySQL table containing two columns: SUBJECT and YEAR. The task is to generate a unique alphanumeric numeric identifier by combining data from both columns. The question arises whether a simple operator, such as , can suffice for this concatenation.

The preferred solution involves the CONCAT function, as demonstrated below:

SELECT CONCAT(`SUBJECT`, ' ', `YEAR`) FROM `table`

This query effectively combines the values in the SUBJECT and YEAR columns with a space as the separator.

Alternatively, if you require a more complex formatting, consider the following approach:

SET @rn := 0;

SELECT CONCAT(`SUBJECT`,'-',`YEAR`,'-',LPAD(@rn := @rn+1,3,'0'))
FROM `table`

In this case, each concatenated string includes a dash '-' separator, followed by the padded row number, ensuring uniqueness within the table.

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