Left in SQL Server Functions: LEFT Function in SQL Server

Left in SQL Server Functions: LEFT Function in SQL Server is easier to understand when the core ideas are paired with practical examples. The sections below explain the topic clearly, highlight useful steps, and point out details that can prevent common errors.

The article will learn and show you how to use the LEFT function in SQL Server to extract some characters from the left side of a given string.

Describe

The LEFT function in SQL Server allows you to extract a substring from a large string, starting from the leftmost character.

Syntax

To use LEFT function in SQL Server, we use the following syntax:

 LEFT(chuoi, so_ky_tu)

Parameters :

chuoi: can be a string, variable or column that you want to extract.
so_ky_tu: a positive integer that specifies the number of characters that will be returned from the cycle, starting from the leftmost character.

Note :

If so_ky_tu exceeds the length of the string, LEFT function returns the original string.
The LEFT function can be used in later versions of SQL Server: SQL Server 2017, SQL Server 2016, SQL Server 2014, SQL Server 2012, SQL Server 2008 R2, SQL Server 2008, and SQL Server 2005.

As an example,

Take a look and explore some examples of LEFT functions in SQL Server.

 SELECT LEFT('TipsMake.com', 12); 
 Result: 'Tipsmake.' 
 
 SELECT LEFT('TipsMake.com', 4); 
 Result: 'Quan' 
 
 SELECT LEFT('Tipsmake', 9); 
 Result: 'Quan Tri ' 
 
 SELECT LEFT('Tipsmake', 100); 
 Result: 'Tipsmake '