SQL Server String Functions
Function	Description
ASCII	Returns the ASCII value for the specific character
CHAR	Returns the character based on the ASCII code
CHARINDEX	Returns the position of a substring in a string
CONCAT	Adds two or more strings together
Concat with +	Adds two or more strings together
CONCAT_WS	Adds two or more strings together with a separator
DATALENGTH	Returns the number of bytes used to represent an expression
DIFFERENCE	Compares two SOUNDEX values, and returns an integer value
FORMAT	Formats a value with the specified format
LEFT	Extracts a number of characters from a string (starting from left)
LEN	Returns the length of a string
LOWER	Converts a string to lower-case
LTRIM	Removes leading spaces from a string
NCHAR	Returns the Unicode character based on the number code
PATINDEX	Returns the position of a pattern in a string
QUOTENAME	Returns a Unicode string with delimiters added to make the string a valid SQL Server delimited identifier
REPLACE	Replaces all occurrences of a substring within a string, with a new substring
REPLICATE	Repeats a string a specified number of times
REVERSE	Reverses a string and returns the result
RIGHT	Extracts a number of characters from a string (starting from right)
RTRIM	Removes trailing spaces from a string
SOUNDEX	Returns a four-character code to evaluate the similarity of two strings
SPACE	Returns a string of the specified number of space characters
STR	Returns a number as string
STUFF	Deletes a part of a string and then inserts another part into the string, starting at a specified position
SUBSTRING	Extracts some characters from a string
TRANSLATE	Returns the string from the first argument after the characters specified in the second argument are translated into the characters specified in the third argument.
TRIM	Removes leading and trailing spaces (or other specified characters) from a string
UNICODE	Returns the Unicode value for the first character of the input expression
UPPER	Converts a string to upper-case

👉WE ARE CREATING A TABLE FOR KNOWING STRING FUNCTION IN EASY WAY.

CREATE TABLE STRING_FUNT(CHAR1 VARCHAR(10),CHAR2 VARCHAR(10));
INSERT INTO STRING_FUNT VALUES('RAM','ABC'),('SHYAM','ABD'),
('RADHA','ABE');

SELECT * FROM STRING_FUNT;

SOME EXAMPLE OF IMPORTANT STRING FUNCTION.

LENGTH FUNCTION

SELECT LEN(CHAR1) FROM STRING_FUNT;

REPLACE FUNTION

SELECT REPLACE(CHAR1,'RAM','RAJ') FROM STRING_FUNT;

REVERESE FUNCTION

SELECT REVERSE(CHAR1) FROM STRING_FUNT WHERE CHAR2 LIKE 'ABD';

LOWER FUNCTION

SELECT LOWER(CHAR2) FROM STRING_FUNT;