How Can I Extract Consecutive Digits from MySQL Text Fields?

Extracting Consecutive Digits from MySQL Text Fields

To effectively extract consecutive digits from text fields in MySQL, there are several approaches:

Using Regular Expressions:

MySQL's built-in regular expression support can be utilized to detect occurrences of two consecutive digits within a text field. However, this method does not extract the digits as a separate field.

Custom Function with PCRE:

For advanced regular expression capabilities, consider implementing LIB_MYSQLUDF_PREG. This open-source library offers functions like PREG_CAPTURE, PREG_POSITION, PREG_REPLACE, and PREG_RLIKE, which enable extracting specific matches from a string.

Customized Function:

An alternate approach is to create a custom function like REGEXP_EXTRACT to extract the longest substring matching the desired regular expression pattern. This function allows you to specify start and end position adjustments to capture digits without including additional characters.

Additional Criteria:

If you need to filter the extracted digits by a specific value, such as greater than 20, you can apply additional criteria in your MySQL query after obtaining the digits as a field.

Example:

Consider the following custom function implementation:

CREATE FUNCTION REGEXP_EXTRACT(string TEXT, exp TEXT)
RETURNS TEXT
DETERMINISTIC
BEGIN
  ...
  ...
END

You can then use this function in your query to extract two consecutive digits from the originaltext field and filter them by value:

SELECT `id`, REGEXP_EXTRACT(`originaltext`, '[0-9][0-9]') AS `digits`
FROM `source`
WHERE `digits` > 20;

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