COALESCE()

• Returns the first non-null expression among its arguments.

SELECT 
	Name, 
	Class, 
	Color, 
	ProductNumber,
	COALESCE(Class, Color, ProductNumber) AS [FirstNotNull]
FROM Production.Product;

SUBSTRING()

• Returns part of a character, binary, text, or image expression.

SELECT SUBSTRING('abcde', 1, 3); -- 'abc'

RIGHT(), LEFT()

• RIGHT Returns the right part of a character string with the specified number of characters.
• LEFT Returns the left part of a character string with the specified number of characters.

SELECT RIGHT('abcde', 3); -- 'cde'
SELECT LEFT('abcde', 3); -- 'abc'

LEN()

• Returns the number of characters of the specified string expression, excluding trailing blanks.

SELECT LEN(N'abcde'); -- 5

DATALENGTH()

• Returns the number of bytes used to represent any expression.

SELECT DATALENGTH(N'abcde'); -- 10

CHARINDEX()

• Searches an expression for another expression and returns its starting position if found.

SELECT CHARINDEX(' ','Itzik Ben-Gan A'); -- 6

PATINDEX()