How to Correctly Replace Multiple Strings in MySQL Records Using the `REPLACE()` Function?

Replacing Strings in Multiple MySQL Records Using replace()

Problem:

A database contains records with corrupted data in a particular column. Specifically, certain characters have been erroneously escaped, disrupting the functionality of generated links. The objective is to replace these incorrect characters in all the affected records using the MySQL replace() function.

Solution:

To use the replace() function in MySQL, follow the syntax:

UPDATE MyTable
SET StringColumn = REPLACE(StringColumn, 'SearchForThis', 'ReplaceWithThis')
WHERE SomeOtherColumn LIKE '%PATTERN%';

In the provided scenario, we need to replace the string "<" with a literal angle bracket "<" in the articleItem column for all records containing "<". Considering the possibility that these characters were escaped to "GREATERTHAN", the query would be as follows:

UPDATE MyTable
SET articleItem = REPLACE(articleItem, 'GREATERTHAN', '>');</p>
<p>If there are multiple characters that need replacement, the replace() function can be nested:</p>
<pre class="brush:php;toolbar:false">UPDATE MyTable
SET articleItem = REPLACE(REPLACE(articleItem, 'GREATERTHAN', '>'), 'LESSTHAN', '<');

Single-Query Approach:

The above query can be used to replace multiple characters in a single query. It is also possible to perform replacements while selecting data:

SELECT REPLACE(MyURLString, 'GREATERTHAN', '>') AS MyURLString
FROM MyTable;

In this example, the replaced string is returned as MyURLString instead of updating the original column.

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