LEFT

Returns the first characters of a string.

Syntax

LEFT( <string>, <n> )

Argument	Description
`<string>`	The text to take from.
`<n>`	How many characters to take. A negative number takes all but the last `-<n>` characters.

Text. NULL when any argument is NULL. The whole string when <n> is at least its length.

LEFT('invoice', -3) is invo.
A <n> that is not an integer is an error.
On large tables the engine runs it in the data store when <n> is a literal of 0 or more; otherwise it runs after the rows are read.

SELECT p.sku, LEFT(p.sku, 2) AS family, COUNT(*) AS products
FROM Product p
GROUP BY p.sku, LEFT(p.sku, 2)

sku	family	products
AB-100	AB	1
AB-210	AB	1