LEFT function in SQL Server

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.

For example

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

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

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