Db2 LEFT

Db2 LEFT() function returns a substring that consists of a specified number of leftmost characters from a string.

Here is the syntax of the LEFT() function:

LEFT(string, length);Code language: SQL (Structured Query Language) (sql)

In this syntax:

• First, specify the source string ( string) from which to extract the substring.
• Second, specify the number of leftmost characters ( length) to be extracted.

This example returns the first three characters of the string 'IBM Db2':

SELECT 
   LEFT('IBM Db2',3) result
FROM 
   sysibm.sysdummy1;Code language: SQL (Structured Query Language) (sql)

The following shows the output:

RESULT  
------- 
IBMCode language: SQL (Structured Query Language) (sql)

See the following authors tables from the sample database:

This example uses the LEFT() function shows the number of the last names for each initial (A, B, C…):

SELECT 
   LEFT(last_name,1) Initial, 
   COUNT(last_name)
FROM authors
GROUP BY 
   LEFT(last_name,1);Code language: SQL (Structured Query Language) (sql)

The output is as follows:

In this tutorial, you have learned how to use the Db2 LEFT() function to return the number of leftmost characters of a string.