Sql String Functions — Free Sql Tutorial

TL;DR: Learn Sql String Functions in Sql with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

Sql String Functions in Sql

SQL provides built-in functions to manipulate text: UPPER(), LOWER(), LENGTH(), TRIM(), SUBSTRING(), REPLACE(), CONCAT(), LIKE with wildcards.

CONCAT(str1, str2) joins strings. CONCAT_WS(sep, str1, str2) joins with a separator. In some databases, || is the concatenation operator.

SUBSTRING(str, start, length) extracts a portion. CHAR_LENGTH() counts characters. POSITION() or INSTR() finds the position of a substring.

LIKE uses wildcards: % means any sequence of characters, _ means exactly one character. ILIKE (PostgreSQL) is case-insensitive LIKE.

SELECT UPPER('hello')             -- 'HELLO'
SELECT LOWER('WORLD')             -- 'world'
SELECT LENGTH('Syllab')           -- 6
SELECT TRIM('  hello  ')          -- 'hello'
SELECT SUBSTRING('Hello',1,3)     -- 'Hel'
SELECT REPLACE('Hi World','World','India')  -- 'Hi India'
SELECT CONCAT('Hello',' '

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