SQL Server LEFT() Function

The LEFT() function in SQL Server extracts a specified number of characters from the left-hand side of a string. It's a very useful tool for working with text data and retrieving specific parts of strings.

LEFT(): Definition and Usage

LEFT() is particularly helpful for extracting prefixes or initial parts of strings. You specify the string and the number of characters you want from the left. If the number of characters you request exceeds the string's length, the entire string is returned.

Syntax


LEFT(string, number_of_chars)

Parameter Values

Parameter	Description
`string`	The string from which you want to extract characters. This is required.
`number_of_chars`	The number of characters to extract from the left side of the string. If this number is larger than the length of the string, the entire string will be returned. This is required.

Examples

Extracting Characters from a Literal String

This example extracts the first three characters ('SQL') from the string 'SQL Tutorial'.

Syntax


SELECT LEFT('SQL Tutorial', 3) AS ExtractString;

Output

SQL

Extracting Characters from a Column

This example extracts the first five characters from the 'CustomerName' column in a 'Customers' table (assuming such a table and column exist).

Syntax


SELECT LEFT(CustomerName, 5) AS ExtractString
FROM Customers;

Output


ExtractString
-------------
(The first five characters of each CustomerName will be displayed here.)

Extracting More Characters Than Exist

If you request more characters than are present, the entire string is returned.

Syntax


SELECT LEFT('SQL Tutorial', 100) AS ExtractString;

Output


SQL Tutorial