Commonly used string functions in SQL Server

len (expression) returns the number of characters (not bytes) of the given string expression, with no trailing spaces.

DATALENGTH (char_expr) returns a string that contains the number of characters but does not contain the following spaces
Length (expression,variable) specifies the lengths of the string or variable names.
SUBSTRING (expression,start,length) Not much to say, take a substring
Right (char_expr,int_expr) returns int_expr characters to the left of the string
Concat (STR1,STR2,...) Returns the string from the parameter link.

DATALENGTH (char_expr) returns a string that contains the number of characters but does not contain the following spaces
Length (expression,variable) specifies the lengths of the string or variable names.
SUBSTRING (expression,start,length) Not much to say, take a substring
Right (char_expr,int_expr) returns int_expr characters to the left of the string
Concat (STR1,STR2,...) Returns the string from the parameter link.

Character Manipulation classes

Upper (char_expr) to uppercase
Lower (char_expr) to lowercase
UCase (String) returns a Variant (string) that contains a string that is converted to uppercase.
LCase (String) returns the lowercase form of the string.
Space (int_expr) generates int_expr spaces
Replicate (char_expr,int_expr) copy string int_expr times
Reverse (char_expr) Reverse string
Stuff (CHAR_EXPR1,START,LENGTH,CHAR_EXPR2) replaces the length character in the string char_expr1 from start with a CHAR_EXPR2
LTrim (char_expr) RTrim (char_expr) Remove spaces
ASCII (char) char (ASCII) two functions correspond, take ASCII code, according to ASCII fetch character

String Lookup

CHARINDEX (char_expr,expression) returns the starting position of the char_expr
Patindex ("%pattern%", expression) returns the starting position of the specified pattern, otherwise 0
Locate (Substr,str,pos) returns a substring substr where the first occurrence of the string str occurs

Reference: Common functions in SQL Server http://www.studyofnet.com/news/1007.html

Commonly used string functions in SQL Server