String functions
Functions for performing string manipulation.
ASCII(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the ASCII code value of the leftmost character of string_exp as an integer.
SELECT ASCII('Elastic');
ASCII('Elastic')
----------------
69
BIT_LENGTH(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the length in bits of the string_exp input expression.
SELECT BIT_LENGTH('Elastic');
BIT_LENGTH('Elastic')
---------------------
56
CHAR(code)
Input:
- integer expression between
0and255. Ifnull, negative, or greater than255, the function returnsnull.
Output: string
Description: Returns the character that has the ASCII code value specified by the numeric input.
SELECT CHAR(69);
CHAR(69)
---------------
E
CHAR_LENGTH(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the length in characters of the input, if the string expression is of a character data type; otherwise, returns the length in bytes of the string expression (the smallest integer not less than the number of bits divided by 8).
SELECT CHAR_LENGTH('Elastic');
CHAR_LENGTH('Elastic')
----------------------
7
CONCAT(
string_exp1,
string_exp2)
Input:
- string expression. Treats
nullas an empty string. - string expression. Treats
nullas an empty string.
Output: string
Description: Returns a character string that is the result of concatenating string_exp1 to string_exp2.
The resulting string cannot exceed a byte length of 1 MB.
SELECT CONCAT('Elasticsearch', ' SQL');
CONCAT('Elasticsearch', ' SQL')
-------------------------------
Elasticsearch SQL
INSERT(
source,
start,
length,
replacement)
Input:
- string expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull.
Output: string
Description: Returns a string where length characters have been deleted from source, beginning at start, and where replacement has been inserted into source, beginning at start.
The resulting string cannot exceed a byte length of 1 MB.
SELECT INSERT('Elastic ', 8, 1, 'search');
INSERT('Elastic ', 8, 1, 'search')
----------------------------------
Elasticsearch
LCASE(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: string
Description: Returns a string equal to that in string_exp, with all uppercase characters converted to lowercase.
SELECT LCASE('Elastic');
LCASE('Elastic')
----------------
elastic
LEFT(
string_exp,
count)
Input:
- string expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull. If0or negative, the function returns an empty string.
Output: string
Description: Returns the leftmost count characters of string_exp.
SELECT LEFT('Elastic',3);
LEFT('Elastic',3)
-----------------
Ela
LENGTH(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the number of characters in string_exp, excluding trailing blanks.
SELECT LENGTH('Elastic ');
LENGTH('Elastic ')
--------------------
7
LOCATE(
pattern,
source
[, start]<3>
)
Input:
- string expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull. - integer expression; optional. If
null,0,1, negative, or not specified, the search starts at the first character position.
Output: integer
Description: Returns the starting position of the first occurrence of pattern within source. The optional start specifies the character position to start the search with. If the pattern is not found within source, the function returns 0.
SELECT LOCATE('a', 'Elasticsearch');
LOCATE('a', 'Elasticsearch')
----------------------------
3
SELECT LOCATE('a', 'Elasticsearch', 5);
LOCATE('a', 'Elasticsearch', 5)
-------------------------------
10
LTRIM(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: string
Description: Returns the characters of string_exp, with leading blanks removed.
SELECT LTRIM(' Elastic');
LTRIM(' Elastic')
-------------------
Elastic
OCTET_LENGTH(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the length in bytes of the string_exp input expression.
SELECT OCTET_LENGTH('Elastic');
OCTET_LENGTH('Elastic')
-----------------------
7
POSITION(
string_exp1,
string_exp2)
Input:
- string expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull.
Output: integer
Description: Returns the position of the string_exp1 in string_exp2. The result is an exact numeric.
SELECT POSITION('Elastic', 'Elasticsearch');
POSITION('Elastic', 'Elasticsearch')
------------------------------------
1
REPEAT(
string_exp,
count)
Input:
- string expression. If
null, the function returnsnull. - integer expression. If
0, negative, ornull, the function returnsnull.
Output: string
Description: Returns a character string composed of string_exp repeated count times.
The resulting string cannot exceed a byte length of 1 MB.
SELECT REPEAT('La', 3);
REPEAT('La', 3)
----------------
LaLaLa
REPLACE(
source,
pattern,
replacement)
Input:
- string expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull.
Output: string
Description: Search source for occurrences of pattern, and replace with replacement.
The resulting string cannot exceed a byte length of 1 MB.
SELECT REPLACE('Elastic','El','Fant');
REPLACE('Elastic','El','Fant')
------------------------------
Fantastic
RIGHT(
string_exp,
count)
Input:
- string expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull. If0or negative, the function returns an empty string.
Output: string
Description: Returns the rightmost count characters of string_exp.
SELECT RIGHT('Elastic',3);
RIGHT('Elastic',3)
------------------
tic
RTRIM(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: string
Description: Returns the characters of string_exp with trailing blanks removed.
SELECT RTRIM('Elastic ');
RTRIM('Elastic ')
-------------------
Elastic
SPACE(count)
Input:
- integer expression. If
nullor negative, the function returnsnull.
Output: string
Description: Returns a character string consisting of count spaces.
The resulting string cannot exceed a byte length of 1 MB.
SELECT SPACE(3);
SPACE(3)
---------------
STARTS_WITH(
source,
pattern)
Input:
- string expression. If
null, the function returnsnull. - string expression. If
null, the function returnsnull.
Output: boolean value
Description: Returns true if the source expression starts with the specified pattern, false otherwise. The matching is case sensitive.
SELECT STARTS_WITH('Elasticsearch', 'Elastic');
STARTS_WITH('Elasticsearch', 'Elastic')
--------------------------------
true
SELECT STARTS_WITH('Elasticsearch', 'ELASTIC');
STARTS_WITH('Elasticsearch', 'ELASTIC')
--------------------------------
false
SUBSTRING(
source,
start,
length)
Input:
- string expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull. - integer expression. If
null, the function returnsnull.
Output: string
Description: Returns a character string that is derived from source, beginning at the character position specified by start for length characters.
SELECT SUBSTRING('Elasticsearch', 0, 7);
SUBSTRING('Elasticsearch', 0, 7)
--------------------------------
Elastic
TRIM(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: string
Description: Returns the characters of string_exp, with leading and trailing blanks removed.
SELECT TRIM(' Elastic ') AS trimmed;
trimmed
--------------
Elastic
UCASE(string_exp)
Input:
- string expression. If
null, the function returnsnull.
Output: string
Description: Returns a string equal to that of the input, with all lowercase characters converted to uppercase.
SELECT UCASE('Elastic');
UCASE('Elastic')
----------------
ELASTIC