How to Sort String Columns Containing Numbers in Ascending Order in MySQL?

Sorting String Columns Containing Numbers in SQL

When sorting string columns that contain numbers, the default MySQL sorting algorithm places numbers after letters. This is not always the desired behavior.

Problem:

Sort the following string column containing numbers in ascending order:

name

a 1

a 12

a 2

a 3

The expected result is:

name

a 1

a 2

a 3

a 12

Solution with SQL:

Assuming the column pattern is always "WORD space NUMBER," the following SQL query can be used:

<code class="sql">SELECT *
FROM table
ORDER BY CAST(SUBSTRING(column, LOCATE(' ', column) + 1) AS SIGNED);</code>

• CAST(): Converts the substring (number) to a numerical value.
• LOCATE(' ', column): Finds the position of the space character.
• SUBSTRING(): Extracts the substring containing the number.

Alternatively, with SUBSTRING_INDEX:

<code class="sql">ORDER BY SUBSTRING_INDEX(column, " ", 1) ASC, CAST(SUBSTRING_INDEX(column, " ", -1) AS SIGNED);</code>

This query uses SUBSTRING_INDEX to extract the word and number parts of the string separately and sorts them accordingly.

Explanation:

This solution relies on the fact that the substring after the space character in the string always contains the number. By converting this substring to a numerical value, we can sort the column numerically, ignoring the letter prefix.

Note:

If the string column does not follow the "WORD space NUMBER" pattern, additional logic or string manipulation functions may be necessary to achieve the desired sorting result.

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