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LEFT

The LEFT function in SQL returns the specified number of characters from the start (left side) of a given string.

Syntax​

LEFT(string, number)

Parameters​

  • string: The original string from which to extract characters.
  • number: The number of characters to extract from the start of the string. This must be an integer.

Return Value​

The function returns a string, which consists of the specified number of characters from the start of the original string. If the original string is shorter than the specified number, the function returns the whole string.

Errors​

  • If the number argument is not an integer, a FunctionRequiresIntegerValue error will be returned.
  • If the string argument is not a string, a FunctionRequiresStringValue error will be returned.

Examples​

Consider a table Item created and filled with the following data:

CREATE TABLE Item (
    name TEXT DEFAULT LEFT('abc', 1)
);
INSERT INTO Item VALUES ('Blop mc blee'), ('B'), ('Steven the &long named$ folken!');

You can use the LEFT function to extract the first three characters of each name:

SELECT LEFT(name, 3) AS test FROM Item;

This will return:

Blo
B
Ste

Note that when the string length is less than the specified number (as with 'B'), the function will return the whole string.