Sql SELECT everything after a certain character

Get a grip on substring extraction

Substrings and delimiters constructed after certain characters? Sounds like a mystery? No worries, let's crack this code together! For an instance, imagine your supplier_reference values look something like 'AB123=supplier_name', and if you're curious to extract everything after '=', you'd set 'char' to '='.

If your string sports a recurring delimiter, and you're eager to unveil the text after the last instance of this delimiter, SUBSTRING_INDEX function in MySQL might be your savior:

SELECT SUBSTRING_INDEX(column, 'char', -1) AS extracted_fresh_string 
FROM table;


If this function looks like a riddle, remember -1 says, "I am interested in what comes after the last occurrence."

Finding ways in different database ecosystems

Not all database systems are built equivalent. Similar nuggets can be obtained differently in other SQL environments. Here's how:

-- MySQL version, let's get to work
SELECT SUBSTRING_INDEX(column, '=', -1) AS result
FROM table;

-- SQL Server version, ready for some magic tricks!
SELECT RIGHT(column, CHARINDEX('=', REVERSE(column)) - 1) AS result
FROM table;

-- PostgreSQL version, unleash your inner nerd
SELECT SPLIT_PART(column, '=', ARRAY_LENGTH(REGEXP_SPLIT_TO_ARRAY(column, '\='), 1)) AS result
FROM table;


Advanced substring extraction: taking the bull by the horns

Knowing how to use LOCATE, RIGHT, and CHAR_LENGTH can help us write cleaner SQL queries. Let's burn through some advanced SQL techniques when dealing with substrings:

Multiple delimiters? No sweat!

Want to get the substring after the second occurrence of a delimiter? Here's how:

SELECT SUBSTRING(column, LOCATE('char', column, LOCATE('char', column) + 1) + 1)
FROM table;


Sweet, right? Let's move on.

Dealing with unknown lengths with CHAR_LENGTH

Here's the trick when the length to extract isn't obvious:

SELECT RIGHT(column, CHAR_LENGTH(column) - LOCATE('char', column))
FROM table;


Handling edge scenarios and testing our answers

Beware of pitfalls when the delimiter is missing or at the end of the string. Here's a wise snippet that takes care of these cases:

SELECT CASE 
         WHEN CHARINDEX('char', column) = 0 THEN NULL-- If no delimiter found, we return NULL, sounds fair?
         ELSE SUBSTRING(column, CHARINDEX('char', column) + 1, LEN(column)) --Otherwise, let's extract that juicy substring
       END AS result
FROM table;


This handles scenarios where the delimiter isn't found, returning NULL, avoiding errors or blank results.

Don't forget to escape special characters in your delimiter if it has a special meaning in SQL. If '|' is your delimiter, escape it with WHERE clause like: WHERE column LIKE '%|%'. Little caution can save unanticipated results, remember to escape!