Supplementary characters (surrogate pairs)

statements

#tsql#statements

A positive integer or expression that specifies how many characters of the expression

are returned. If

length is negative, an error is generated and the statement is terminated. If the sum

of start

and length

is greater than the number of characters in expression

, the whole value expression beginning at

start is returned. If

length is omitted, all characters from the start

position to the end of the expression is returned.

You can use substring with an optional length

argument. However, if you use for

length

returns. Review

E. Use SUBSTRING with optional length argument for an

example.

expression is one of the supported character data types. Returns

binary data if expression

is one of the supported data types. The returned string is the

same type as the specified expression with the exceptions shown in the following table.

You must specify the values for start

and length

in number of characters for

, or data types. For ,

, or data types, you must specify these

values in bytes.

The expression

must be or

when the start

or length

contains a value larger than 2,147,483,647.

When you use supplementary character (SC) collations, both start

and length

count each surrogate pair in

expression as a single character. For more information, see

Collation and

Unicode support.

name

Initial

ThirdAndFourthCharacters

NULL

SUBSTRING

NULL