STRING Functions
ASCII(character_expression)
Returns the ASCII code value of the left-most character of the character expression.
- character_expression: The character expression.
SELECT ASCII('0');
-- Result: 48
CHAR(integer_expression)
Converts the integer ASCII code to the corresponding character.
- integer_expression: The integer from 0 through 255.
SELECT CHAR(48);
-- Result: '0'
CHARINDEX(expressionToFind ,expressionToSearch [,start_location ])
Returns the starting position of the specified expression in the character string.
- expressionToFind: The character expression to find.
- expressionToSearch: The character expression, typically a column, to search.
- start_location: An optional character position to start searching for expressionToFind in expressionToSearch.
SELECT CHARINDEX('456', '0123456');
-- Result: 4
SELECT CHARINDEX('456', '0123456', 5);
-- Result: -1
CHAR_LENGTH(character_expression),
Returns the number of UTF-8 characters present in the expression.
- character_expression: The set of characters to be evaluated for length.
SELECT CHAR_LENGTH('sample text') FROM Account LIMIT 1
-- Result: 11
CONCAT(string_value1, string_value2, ..., string_valueN)
Returns the string that is the concatenation of two or more string values.
- string_value1: The first string to be concatenated.
- string_value2: The second string to be concatenated.
- string_valueN: (optional) Any additional strings to be concatenated.
SELECT CONCAT('Hello, ', 'world!');
-- Result: 'Hello, world!'
CONTAINS(expressionToSearch, expressionToFind)
Returns 1 if expressionToFind is found within expressionToSearch; otherwise, 0.
- expressionToSearch: The character expression, typically a column, to search.
- expressionToFind: The character expression to find.
SELECT CONTAINS('0123456', '456');
-- Result: 1
SELECT CONTAINS('0123456', 'Not a number');
-- Result: 0
ENDSWITH(character_expression, character_suffix)
Returns 1 if character_expression ends with character_suffix; otherwise, 0.
- character_expression: The character expression.
- character_suffix: The character suffix to search for.
SELECT ENDSWITH('0123456', '456');
-- Result: 1
SELECT ENDSWITH('0123456', '012');
-- Result: 0
FILESIZE(uri)
Returns the number of bytes present in the file at the specified file path.
- uri: The path of the file from which to read the size.
SELECT FILESIZE('C:/Users/User1/Desktop/myfile.txt');
-- Result: 23684
FORMAT(value [, parseFormat], format )
Returns the value formatted with the specified format.
- value: The string to format.
- format: The string specifying the output syntax of the date or numeric format.
- parseFormat: The string specifying the input syntax of the date value. Not applicable to numeric types.
SELECT FORMAT(12.34, '#');
-- Result: 12
SELECT FORMAT(12.34, '#.###');
-- Result: 12.34
SELECT FORMAT(1234, '0.000E0');
-- Result: 1.234E3
SELECT FORMAT('2019/01/01', 'yyyy-MM-dd');
-- Result: 2019-01-01
SELECT FORMAT('20190101', 'yyyyMMdd', 'yyyy-MM-dd');
-- Result: '2019-01-01'
HASHBYTES(algorithm, value)
Returns the hash of the input value as a byte array using the given algorithm. The supported algorithms are MD5, SHA1, SHA2_256, SHA2_512, SHA3_224, SHA3_256, SHA3_384, and SHA3_512.
- algorithm: The algorithm to use for hashing. Must be one of MD5, SHA1, SHA2_256, SHA2_512, SHA3_224, SHA3_256, SHA3_384, or SHA3_512.
- value: The value to hash. Must be either a string or byte array.
SELECT HASHBYTES('MD5', 'Test');
-- Result (byte array): 0x0CBC6611F5540BD0809A388DC95A615B
INDEXOF(expressionToSearch, expressionToFind [,start_location ])
Returns the starting position of the specified expression in the character string.
- expressionToSearch: The character expression, typically a column, to search.
- expressionToFind: The character expression to find.
- start_location: An optional character position to start searching for expressionToFind in expressionToSearch.
SELECT INDEXOF('0123456', '456');
-- Result: 4
SELECT INDEXOF('0123456', '456', 5);
-- Result: -1
JSON_EXTRACT(json, jsonpath)
Selects any value in a JSON array or object. The path to the array is specified in the jsonpath argument. Return value is numeric or null.
- json: The JSON document to extract.
- jsonpath: The XPath used to select the nodes. The JSONPath must be a string constant. The values of the nodes selected will be returned in a token-separated list.
SELECT JSON_EXTRACT('{"test": {"data": 1}}', '$.test');
-- Result: '{"data":1}'
SELECT JSON_EXTRACT('{"test": {"data": 1}}', '$.test.data');
-- Result: 1
SELECT JSON_EXTRACT('{"test": {"data": [1, 2, 3]}}', '$.test.data[1]');
-- Result: 2
LEFT ( character_expression , integer_expression )
Returns the specified number of characters counting from the left of the specified string.
- character_expression: The character expression.
- integer_expression: The positive integer that specifies how many characters will be returned counting from the left of character_expression.
SELECT LEFT('1234567890', 3);
-- Result: '123'
LEN(string_expression)
Returns the number of characters of the specified string expression.
- string_expression: The string expression.
SELECT LEN('12345');
-- Result: 5
LOCATE(substring,string)
Returns an integer representing how many characters into the string the substring appears.
- substring: The substring to find inside larger string.
- string: The larger string that is searched for the substring.
- start locations: An optional integer that sets the character position (offset) from which to start searching.
SELECT LOCATE('sample','XXXXXsampleXXXXX');
-- Result: 6
SELECT LOCATE('sample', 'XXXXXsampleXXXXX', 7)
-- Result: 0
LOWER ( character_expression )
Returns the character expression with the uppercase character data converted to lowercase.
- character_expression: The character expression.
SELECT LOWER('MIXED case');
-- Result: 'mixed case'
LTRIM(character_expression)
Returns the character expression with leading blanks removed.
- character_expression: The character expression.
SELECT LTRIM(' trimmed');
-- Result: 'trimmed'
MASK(string_expression, mask_character [, start_index [, end_index ]])
Replaces the characters between start_index and end_index with the mask_character within the string.
- string_expression: The string expression to be searched.
- mask_character: The character to mask with.
- start_index: The optional number of characters to leave unmasked at beginning of string. Defaults to 0.
- end_index: The optional number of characters to leave unmasked at end of string. Defaults to 0.
SELECT MASK('1234567890','*',);
-- Result: '**********'
SELECT MASK('1234567890','*', 4);
-- Result: '1234******'
SELECT MASK('1234567890','*', 4, 2);
-- Result: '1234****90'
NCHAR(integer_expression)
Returns the Unicode character with the specified integer code as defined by the Unicode standard.
- integer_expression: The integer from 0 through 65535 (0 through xFFFF).
OCTET_LENGTH(character_expression),
Returns the number of bytes present in the expression.
- character_expression: The set of characters to be be evaluated.
SELECT OCTET_LENGTH('text') FROM Account LIMIT 1
-- Result: 4
PATINDEX(pattern, expression)
Returns the starting position of the first occurrence of the pattern in the expression. Returns 0 if the pattern is not found.
- pattern: The character expression that contains the sequence to be found. The wild-card character % can be used only at the start or end of the expression.
- expression: The expression, typically a column, to search for the pattern.
SELECT PATINDEX('123%', '1234567890');
-- Result: 1
SELECT PATINDEX('%890', '1234567890');
-- Result: 8
SELECT PATINDEX('%456%', '1234567890');
-- Result: 4
POSITION(expressionToFind IN expressionToSearch)
Returns the starting position of the specified expression in the character string.
- expressionToFind: The character expression to find.
- expressionToSearch: The character expression, typically a column, to search.
SELECT POSITION('456' IN '123456');
-- Result: 4
SELECT POSITION('x' IN '123456');
-- Result: 0
QUOTENAME(character_string [, quote_character])
Returns a valid SQL Server-delimited identifier by adding the necessary delimiters to the specified Unicode string.
- character_string: The string of Unicode character data. The string is limited to 128 characters. Inputs greater than 128 characters return null.
- quote_character: An optional single character to be used as the delimiter. These include:
- a single quotation mark (')
- a left or right bracket ([])
- a double quotation mark (")
- a left or right parenthesis ( () )
- a greater or less than sign (><)
- a left or right brace ({})
- a backtick (`)
If quote_character is not specified brackets are used. If an unacceptable character is supplied, it returns NULL.
SELECT QUOTENAME('table_name');
-- Result: '[table_name]'
SELECT QUOTENAME('table_name', '"');
-- Result: '"table_name"'
SELECT QUOTENAME('table_name', '[');
-- Result: '[table_name]'
REPLACE(string_expression, string_pattern, string_replacement)
Replaces all occurrences of a string with another string.
- string_expression: The string expression to be searched. This can be a character or binary data type.
- string_pattern: The substring to be found. Cannot be an empty string.
- string_replacement: The replacement string.
SELECT REPLACE('1234567890', '456', '|');
-- Result: '123|7890'
SELECT REPLACE('123123123', '123', '.');
-- Result: '...'
SELECT REPLACE('1234567890', 'a', 'b');
-- Result: '1234567890'
REPLICATE ( string_expression ,integer_expression )
Repeats the string value the specified number of times.
- string_expression: The string to replicate.
- integer_expression: The repeat count.
SELECT REPLACE('x', 5);
-- Result: 'xxxxx'
REVERSE ( string_expression )
Returns the reverse order of the string expression.
- string_expression: The string.
SELECT REVERSE('1234567890');
-- Result: '0987654321'
RIGHT ( character_expression , integer_expression )
Returns the right part of the string with the specified number of characters.
- character_expression: The character expression.
- integer_expression: The positive integer that specifies how many characters of the character expression will be returned.
SELECT RIGHT('1234567890', 3);
-- Result: '890'
RTRIM(character_expression)
Returns the character expression after it removes trailing blanks.
- character_expression: The character expression.
SELECT RTRIM('trimmed ');
-- Result: 'trimmed'
SOUNDEX(character_expression)
Returns the four-character Soundex code, based on how the string sounds when spoken.
- character_expression: The alphanumeric expression of character data.
SELECT SOUNDEX('smith');
-- Result: 'S530'
SPACE(repeatcount)
Returns the string that consists of repeated spaces.
- repeatcount: The number of spaces.
SELECT SPACE(5);
-- Result: ' '
SPLIT(string, delimiter, offset)
Returns a section of the string between to delimiters.
- string: The string to split.
- delimiter: The character to split the string with.
- offset: The number of the split to return. Positive numbers are treated as offsets from the left, and negative numbers are treated as offsets from the right.
SELECT SPLIT('a/b/c/d', '/', 1);
-- Result: 'a'
SELECT SPLIT('a/b/c/d', '/', -2);
-- Result: 'c'
STARTSWITH(character_expression, character_prefix)
Returns 1 if character_expression starts with character_prefix; otherwise, 0.
- character_expression: The character expression.
- character_prefix: The character prefix to search for.
SELECT STARTSWITH('0123456', '012');
-- Result: 1
SELECT STARTSWITH('0123456', '456');
-- Result: 0
STR ( float_expression [ , integer_length [ , integer_decimal ] ] )
Returns the character data converted from the numeric data. For example, STR(123.45, 6, 1) returns 123.5.
- float_expression: The float expression.
- length: The optional total length to return. This includes decimal point, sign, digits, and spaces. The default is 10.
- decimal: The optional number of places to the right of the decimal point. The decimal must be less than or equal to 16.
SELECT STR('123.456');
-- Result: '123'
SELECT STR('123.456', 2);
-- Result: '**'
SELECT STR('123.456', 10, 2);
-- Result: '123.46'
STUFF(character_expression , integer_start , integer_length , replaceWith_expression)
Inserts a string into another string. It deletes the specified length of characters in the first string at the start position and then inserts the second string into the first string at the start position.
- character_expression: The string expression.
- start: The integer value that specifies the location to start deletion and insertion. If start or length is negative, null is returned. If start is longer than the string to be modified, character_expression, null is returned.
- length: The integer that specifies the number of characters to delete. If length is longer than character_expression, deletion occurs up to the last character in replaceWith_expression.
- replaceWith_expression: The expression of character data that will replace length characters of character_expression beginning at the start value.
SELECT STUFF('1234567890', 3, 2, 'xx');
-- Result: '12xx567890'
SUBSTRING(string_value FROM start FOR length)
Returns the part of the string with the specified length; starts at the specified index.
- string_value: The character string.
- start: The positive integer that specifies the start index of characters to return.
- length: Optional. The positive integer that specifies how many characters will be returned.
SELECT SUBSTRING('1234567890' FROM 3 FOR 2);
-- Result: '34'
SELECT SUBSTRING('1234567890' FROM 3);
-- Result: '34567890'
You can also drop the FROM and FOR clauses:
SELECT SUBSTRING('1234567890', 3, 2)
--Result: '34'
SELECT SUBSTRING('1234567890', 3)
--Result: '34567890'
TOSTRING(string_value1)
Converts the value of this instance to its equivalent string representation.
- string_value1: The string to be converted.
SELECT TOSTRING(123);
-- Result: '123'
SELECT TOSTRING(123.456);
-- Result: '123.456'
SELECT TOSTRING(null);
-- Result: ''
TRIM(trimspec trimchar FROM string_value)
Returns the character expression with leading and/or trailing blanks removed.
- trimspec: Optional. If included must be one of the keywords BOTH, LEADING or TRAILING.
- trimchar: Optional. If included should be a one-character string value.
- string_value: The string value to trim.
SELECT TRIM(' trimmed ');
-- Result: 'trimmed'
SELECT TRIM(LEADING FROM ' trimmed ');
-- Result: 'trimmed '
SELECT TRIM('-' FROM '-----trimmed-----');
-- Result: 'trimmed'
SELECT TRIM(BOTH '-' FROM '-----trimmed-----');
-- Result: 'trimmed'
SELECT TRIM(TRAILING '-' FROM '-----trimmed-----');
-- Result: '-----trimmed'
UNICODE(ncharacter_expression)
Returns the integer value defined by the Unicode standard of the first character of the input expression.
- ncharacter_expression: The Unicode character expression.
UPPER ( character_expression )
Returns the character expression with lowercase character data converted to uppercase.
- character_expression: The character expression.
SELECT UPPER('MIXED case');
-- Result: 'MIXED CASE'
XML_EXTRACT(xml, xpath [, separator])
Extracts an XML document using the specified XPath to flatten the XML. A comma is used to separate the outputs by default, but this can be changed by specifying the third parameter.
- xml: The XML document to extract.
- xpath: The XPath used to select the nodes. The nodes selected will be returned in a token-separated list.
- separator: The optional token used to separate the items in the flattened response. If this is not specified, the separator will be a comma.
SELECT XML_EXTRACT('<vowels><ch>a</ch><ch>e</ch><ch>i</ch><ch>o</ch><ch>u</ch></vowels>', '/vowels/ch');
-- Result: 'a,e,i,o,u'
SELECT XML_EXTRACT('<vowels><ch>a</ch><ch>e</ch><ch>i</ch><ch>o</ch><ch>u</ch></vowels>', '/vowels/ch', ';');
-- Result: 'a;e;i;o;u'