# MySQL string functions

String functions are used to perform an operation on an input string and return an output string.
Some MYSQL string functions and their uses:
1.	ASCII: Returns the ASCII value for the specific character
Example: SELECT ASCII('A'); returns 65
2.	CHAR_LENGTH: Returns the length of a string (in characters)
Example:  SELECT CHAR_LENGTH("SQL Tutorial") AS LengthOfString;  returns 12
3.	CHARACTER_LENGTH: Returns the length of a string (in characters)
Example: SELECT CHARACTER_LENGTH("SQL Tutorial") AS LengthOfString; returns 12
4.	CONCAT: Adds two or more expressions together	
Example: SELECT CONCAT("SQL ", "Tutorial ", "is ", "fun!") AS ConcatenatedString; returns SQL Tutorial is fun!
5.	CONCAT_WS: Adds two or more expressions together with a separator
Example: SELECT CONCAT_WS("-", "SQL", "Tutorial", "is", "fun!") AS ConcatenatedString; returns SQL-Tutorial-is-fun!
6.	FIELD: Returns the index position of a value in a list of values
Example: SELECT FIELD("q", "s", "q", "l"); returns 2
7.	FIND_IN_SET: Returns the position of a string within a list of strings
Example: SELECT FIND_IN_SET("q", "s,q,l"); returns 2
8.	FORMAT: Formats a number to a format like "#,###,###.##", rounded to a specified number of decimal places
Example: SELECT FORMAT(250500.5634, 2); returns 250,500.56
9.	INSERT: Insert a string within a string at the specified position and for a certain number of characters
Example: SELECT INSERT("W3Schools.com", 1, 9, "Example"); returns Example.com
10.	INSTR: Returns the position of the first occurrence of a string in another string
Example: SELECT INSTR("W3Schools.com", "3") AS MatchPosition; returns 2
11.	LCASE: Converts a string to lower-case
Example: SELECT LCASE("SQL Tutorial is FUN!") AS LowercaseText; returns sql tutorial is fun!
12.	LEFT: Extracts a number of characters from a string (starting from left)
Example: SELECT LEFT("SQL Tutorial", 3) AS ExtractString; returns SQL
13.	LENGTH: Returns the length of a string (in bytes)
Example: SELECT LENGTH("SQL Tutorial") AS LengthOfString; returns 12
14.	LOCATE: Returns the position of the first occurrence of a substring in a string
Example: SELECT LOCATE("3", "W3Schools.com") AS MatchPosition; returns 2
15.	LOWER: Converts a string to lower-case
Example: SELECT LOWER("SQL Tutorial is FUN!"); returns sql tutorial is fun!
16.	LPAD: Left-pads a string with another string, to a certain length
Example: SELECT LPAD("SQL Tutorial", 20, "ABC"); returns ABCABCABSQL Tutorial
17.	LTRIM: Removes leading spaces from a string
Example: SELECT LTRIM("    SQL Tutorial") AS LeftTrimmedString;  returns SQL Tutorial
18.	MID: Extracts a substring from a string (starting at any position)
Example: SELECT MID("SQL Tutorial", 5, 3) AS ExtractString; returns Tut
19.	POSITION: Returns the position of the first occurrence of a substring in a string
Example: SELECT POSITION("3" IN "W3Schools.com") AS MatchPosition; returns 2
20.	REPEAT: Repeats a string as many times as specified
Example: SELECT REPEAT("SQL Tutorial", 3); returns SQL TutorialSQL TutorialSQL Tutorial
21.	REPLACE: Replaces all occurrences of a substring within a string, with a new substring
Example: SELECT REPLACE("SQL Tutorial", "SQL", "HTML"); returns HTML Tutorial
22.	REVERSE: Reverses a string and returns the result
Example: SELECT REVERSE("SQL Tutorial"); returns lairotuT LQS
23.	RIGHT: Extracts a number of characters from a string (starting from right)
Example: SELECT RIGHT("SQL Tutorial is cool", 4) AS ExtractString; returns cool
24.	RPAD: Right-pads a string with another string, to a certain length
Example: SELECT RPAD("SQL Tutorial", 20, "ABC"); returns SQL TutorialABCABCAB
25.	RTRIM: Removes trailing spaces from a string
Example: SELECT RTRIM("SQL Tutorial    ") AS RightTrimmedString; returns SQL Tutorial
26.	SPACE: Returns a string of the specified number of space characters
Example: SELECT SPACE(10); returns  “          “
27.	STRCMP: Compares two strings
Example: SELECT STRCMP("SQL Tutorial","SQL Tutorial"); returns 0
28.	SUBSTR: Extracts a substring from a string (starting at any position)
Example: SELECT SUBSTR("SQL Tutorial", 5, 3) AS ExtractString; returns Tut
29.	SUBSTRING: Extracts a substring from a string (starting at any position)
Example: SELECT SUBSTRING("SQL Tutorial", 5, 3) AS ExtractString; returns Tut
30.	SUBSTRING_INDEX: Returns a substring of a string before a specified number of delimiters occurs
Example: 
SELECT SUBSTRING_INDEX("www.w3schools.com", ".", 2); returns www.w3schools
SELECT SUBSTRING_INDEX("www.w3schools.com", ".", 1); returns www
31.	TRIM: Removes leading and trailing spaces from a string
Example: SELECT TRIM("    SQL Tutorial    ") AS TrimmedString; returns SQL Tutorial
32.	UCASE: Converts a string to upper-case
Example: SELECT UCASE("SQL Tutorial is FUN!"); returns SQL TUTORIAL IS FUN!
33.	UPPER: Converts a string to upper-case
Example: SELECT UPPER("SQL Tutorial is FUN!"); returns SQL TUTORIAL IS FUN!