Page 187 - SQL

Chapter 52: String Functions

Introduction

String functions perform operations on string values and return either numeric or string values.

Using string functions, you can, for example, combine data, extract a substring, compare strings,
or convert a string to all uppercase or lowercase characters.

Syntax

• CONCAT ( string_value1, string_value2 [, string_valueN ] )
• LTRIM ( character_expression )
• RTRIM ( character_expression )
• SUBSTRING ( expression ,start , length )
• ASCII ( character_expression )
• REPLICATE ( string_expression ,integer_expression )
• REVERSE ( string_expression )
• UPPER ( character_expression )
• TRIM ( [ characters FROM ] string )
• STRING_SPLIT ( string , separator )
• STUFF ( character_expression , start , length , replaceWith_expression )
• REPLACE ( string_expression , string_pattern , string_replacement )

Remarks

String functions reference for Transact-SQL / Microsoft

String functions reference for MySQL

String functions reference for PostgreSQL

Examples

Trim empty spaces

Trim is used to remove write-space at the beginning or end of selection

In MSSQL there is no single TRIM()

SELECT LTRIM(' Hello ') --returns 'Hello '
SELECT RTRIM(' Hello ') --returns ' Hello'
SELECT LTRIM(RTRIM(' Hello ')) --returns 'Hello'

MySql and Oracle

https://riptutorial.com/ 169