String Functions
Function: concat('str1', 'str2')
This function concatenates two strings into one.
SELECT concat('Coola','Data')
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--> CoolaData
Function: left('str', numeric_expr)
This function returns a substring of numeric_expr characters starting the count from the leftmost character of 'str'. The full string will be returned if the numeric_exp is longer than 'str'.
SELECT left('CoolaData', 4);
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--> Cool
Function: length('str')
This function returns the length of 'str'.
SELECT length('CoolaData');
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--> 9
Function: lower('str')
This function returns 'str' converted to lowercase characters.
SELECT lower('CoolaData');
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--> cooladata
Function: lpad('str1', numeric_expr, 'str2')
This function returns the string str2, left-padded with the string str1 to a length of numeric_expr characters. The return value is shortened to numeric_expr characters if the returned string would be longer than numeric_expr.
SELECT lpad('Data', 9, 'Coolaborator')
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--> CoolaData
Function: right('str', numeric_expr)
This function returns the rightmost numeric_expr characters of str. If the number is longer than the string, it will return the whole string.
SELECT right('CoolaData', 4)
|
--> Data
Function: rpad('str1', numeric_expr, 'str2')
This function returns the string str2, right-padded with the string str1 to a length of numeric_expr characters. The return value is shortened to numeric_expr characters if the returned string would be longer than numeric_expr.
SELECT rpad('Coola', 9, 'Datamart')
|
--> CoolaData
Function: substr('str', start_from, sub_len)
This function returns a substring of str that is up to sub_len characters long, and that begins from the point in str that is specified by start_from. Counting starts at 1, so the first character in the string is in position 1 (not zero). If start_from is 3, the substring begins with the 3rd character from the left in str. If start_from is -3, the substring begins with the 3rd character from the right in str.
SELECT substr('CoolaData', -4, 4)
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--> Data
SELECT substr('CoolaData', 1, 4)
|
--> Cool
Function: upper('str')
This function returns the string str in uppercase letters (only Latin characters).
SELECT upper('cooladata')
|
--> COOLADATA
Note: All regular expression support using the re2 library, see that documentation for its regular expression syntax.
Function: regexp_match('str', 'reg_exp')
This function returns true if 'str' matches the regular expression.
SELECT regexp_match ('ABCabc123xyz', '23x')
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--> true
Function: regexp_extract('str', 'reg_exp')
This function returns the portion of 'str' that matches the capturing group within the regular expression.
Function: regexp_replace('orig_str', 'reg_exp', 'replace_str')
This function returns a string where any substring of orig_str that matches reg_exp is replaced with replace_str.
SELECT regexp_replace ('Hello', 'lo', 'p')
|
--> Help
Note: Regular Expression processing is based on http://code.google.com/p/re2/.