String Functions
Functions for performing string manipulation.
ASCII(string_exp) 1
- string expression. If
null
, the function returnsnull
.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
Output: integer
Description: Returns the length in bits of the string_exp
input expression.
SELECT BIT_LENGTH('Elastic');
BIT_LENGTH('Elastic')
---------------------
56
CHAR(code) 1
- integer expression between
0
and255
. Ifnull
, negative, or greater than255
, the function returnsnull
.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
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, 1
string_exp2) 2
- string expression. Treats
null
as an empty string. - string expression. Treats
null
as an empty string.
Input:
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, 1
start, 2
length, 3
replacement) 4
- 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
.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
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, 1
count) 2
- string expression. If
null
, the function returnsnull
. - integer expression. If
null
, the function returnsnull
. If0
or negative, the function returns an empty string.
Input:
Output: string
Description: Returns the leftmost count characters of string_exp
.
SELECT LEFT('Elastic',3);
LEFT('Elastic',3)
-----------------
Ela
LENGTH(string_exp) 1
- string expression. If
null
, the function returnsnull
.
Input:
Output: integer
Description: Returns the number of characters in string_exp
, excluding trailing blanks.
SELECT LENGTH('Elastic ');
LENGTH('Elastic ')
--------------------
7
LOCATE(
pattern, 1
source 2
[, start]<3>
)
- 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.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
Output: string
Description: Returns the characters of string_exp
, with leading blanks removed.
SELECT LTRIM(' Elastic');
LTRIM(' Elastic')
-------------------
Elastic
OCTET_LENGTH(string_exp) 1
- string expression. If
null
, the function returnsnull
.
Input:
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, 1
string_exp2) 2
- string expression. If
null
, the function returnsnull
. - string expression. If
null
, the function returnsnull
.
Input:
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, 1
count) 2
- string expression. If
null
, the function returnsnull
. - integer expression. If
0
, negative, ornull
, the function returnsnull
.
Input:
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, 1
pattern, 2
replacement) 3
- string expression. If
null
, the function returnsnull
. - string expression. If
null
, the function returnsnull
. - string expression. If
null
, the function returnsnull
.
Input:
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, 1
count) 2
- string expression. If
null
, the function returnsnull
. - integer expression. If
null
, the function returnsnull
. If0
or negative, the function returns an empty string.
Input:
Output: string
Description: Returns the rightmost count characters of string_exp
.
SELECT RIGHT('Elastic',3);
RIGHT('Elastic',3)
------------------
tic
RTRIM(string_exp) 1
- string expression. If
null
, the function returnsnull
.
Input:
Output: string
Description: Returns the characters of string_exp
with trailing blanks removed.
SELECT RTRIM('Elastic ');
RTRIM('Elastic ')
-------------------
Elastic
SPACE(count) 1
- integer expression. If
null
or negative, the function returnsnull
.
Input:
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, 1
pattern) 2
- string expression. If
null
, the function returnsnull
. - string expression. If
null
, the function returnsnull
.
Input:
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, 1
start, 2
length) 3
- string expression. If
null
, the function returnsnull
. - integer expression. If
null
, the function returnsnull
. - integer expression. If
null
, the function returnsnull
.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
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) 1
- string expression. If
null
, the function returnsnull
.
Input:
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