How Can I Extract Consecutive Digits from a MySQL Text Field?

Extracting Consecutive Digits from MySQL Text Field

Manipulating numerical data from a text field can be challenging in MySQL. To extract consecutive digits from such a field, it's recommended to utilize MySQL functions or external libraries.

Using LIB_MYSQLUDF_PREG Library:

The LIB_MYSQLUDF_PREG library provides powerful regular expression functions, including PREG_CAPTURE for substring extraction. By installing this library into MySQL, you can access functions like:

• PREG_CAPTURE(regex, string): Extracts the first matching substring from the string based on the specified regular expression.

Custom Function for Simpler Extraction:

Alternatively, the following custom MySQL function can be created for basic extraction:

CREATE FUNCTION REGEXP_EXTRACT(string TEXT, exp TEXT)
RETURNS TEXT
DETERMINISTIC
BEGIN
  -- Extract longest matching substring adjusted for ^ or $ in regex

Usage:

To use this function, call it as follows:

SELECT REGEXP_EXTRACT(originaltext, '[0-9][0-9]') AS extracted_digits
FROM source
WHERE originaltext regexp '[0-9][0-9]'

This will extract the first matching pair of digits from each matching originaltext. Additional criteria, such as comparing extracted digits to a value, can be added to the query as needed.

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