String Functions
String functions perform various manipulations on character strings. Place character
strings within single quotes.
Functions
ASCII
This function converts a single character string to its corresponding ASCII code,
between 0 and 255. If the character expression evaluates to multiple characters,
the ASCII code corresponding to the first character in the expression is returned.
Syntax
ASCII(strExpr)
Where
strExpr is any expression that evaluates to a character string.
BIT_LENGTH
This function returns the length, in bits, of a specified string. Each Unicode character
is 2 bytes in length (equal to 16 bits).
Syntax
BIT_LENGTH(strExpr)
Where
strExpr is any expression that evaluates to character string.
CHAR
This function converts a numeric value between 0 and 255 to the character value
corresponding to the ASCII code.
Syntax
CHAR(numExpr)
Where
numExpr is any expression that evaluates to a numeric value between 0 and
255.
CHAR_LENGTH
This function returns the length, in number of characters, of a specified string.
Leading and trailing blanks are not counted in the length of the string.
Syntax
CHAR_LENGTH(strExpr)
Where
strExpr is any expression that evaluates to a character string.
CONCAT
There are two forms of this function. The first form concatenates two character
strings. The second form uses the character string concatenation character to
concatenate more than two character strings.
To concatenate two strings
Syntax
CONCAT(strExpr1, strExpr2)
Where
strExpr are expressions that evaluate to character strings, separated by commas.
To concatenate more than two strings
Syntax
CONCAT(strExpr1, strExpr2 || strExpr3)
Where
strExprs are expressions that evaluate to character strings, separated by commas
and the character string concatenation operator || (double vertical
bars). First, strExpr2 is concatenated with strExpr3 to produce an intermediate
string, then both strExpr1 and the intermediate string are concatenated by the
CONCAT function to produce the final string.
INSERT
This function inserts a specified character string into a specified location in another
character string.
Syntax
INSERT(strExpr1, integer1, integer2, strExpr2)
Where
strExpr1 is any expression that evaluates to a character string. Identifies the
target character string.
integer1 is any positive integer that represents the number of characters from
the beginning of the target string where the second string is to be inserted.
integer2 is any positive integer that represents the number of characters in the
target string to be replaced by the second string.
strExpr2 is any expression that evaluates to a character string. Identifies the
character string to be inserted into the target string.
LEFT
This function returns a specified number of characters from the left of a string.
Syntax
LEFT(strExpr, integer)
Where
strExpr is any expression that evaluates to a character string.
integer is any positive integer that represents the number of characters from
the left of the string to return.
LENGTH
This function returns the length, in number of characters, of a specified string. The
length is returned excluding any trailing blank characters.
Syntax
LENGTH(strExpr)
Where
strExpr is any expression that evaluates to a character string.
LOCATE
This function returns the numeric position of a character string in another character
string. If the character string is not found in the string being searched, the function
returns a value of 0.
If you want to specify a starting position to begin the search, include the integer
argument. The numeric position to return is determined by counting the first character
in the string as occupying position 1, regardless of the value of the integer
argument.
Syntax
LOCATE(strExpr1, strExpr2 [, integer])
Where
strExpr1 is any expression that evaluates to a character string. Identifies the
string for which to search.
strExpr2 is any expression that evaluates to a character string. Identifies the
string to be searched.
integer is any positive (nonzero) integer that represents the starting position to
begin to look for the character string. The integer argument is optional.
Examples
This example returns 4 as the numerical position of the letter d in the character
string abcdef:
Locate(‘d’, ‘abcdef’)
This example returns 0, because the letter g is not found within the string being
searched.
Locate(‘g’, ‘abcdef’)
This example returns 4 as the numeric position of the letter d in the character string
abcdef. The search begins with the letter c, the third character in the string. The
numeric position to return is determined by counting the letter ‘a’ as occupying
position 1.
LOCATE(‘d’ ‘abcdef’, 3)
This example returns 0, because the letter b occurs in the string before the starting
position to begin the search.
LOCATE(‘b’ ‘abcdef’, 3)
LOWER
This function converts a character string to lowercase.
Syntax
LOWER(strExpr)
Where
strExpr is any expression that evaluates to a character string.
OCTET_LENGTH
This function returns the number of bits, in base 8 units (number of bytes), of a
specified string.
Syntax
OCTET_LENGTH(strExpr)
Where
strExpr is any expression that evaluates to a character string.
POSITION
This function returns the numeric position of strExpr1 in a character expression. If
strExpr1 is not found, the function returns 0. See also “LOCATE” for related information.
Syntax
POSITION(strExpr1 IN strExpr2)
Where
strExpr1 is any expression that evaluates to a character string. Identifies the
string to search for in the target string.
strExpr2 is any expression that evaluates to a character string. Identifies the
target string to be searched.
Examples
This example returns 4 as the position of the letter d in the character string abcdef:
POSITION(‘d’, ‘abcdef’)
This example returns 0 as the position of the number 9 in the character string
123456, because the number 9 is not found.
POSITION(‘9’, ‘123456’)
REPEAT
This function repeats a specified expression n times.
Syntax
REPEAT(strExpr, integer)
Where
strExpr is any expression that evaluates to a character string.
integer is any positive integer that represents the number of times to repeat
the character string.
Example
This example repeats abc four times:
REPEAT(‘abc’, 4)
REPLACE
This function replaces one or more characters from a specified character expression
with one or more other characters.
Syntax
REPLACE(strExpr1, strExpr2, strExpr3)
Where
strExpr1 is any expression that evaluates to a character string. This is the string
in which characters are to be replaced.
strExpr2 is any expression that evaluates to a character string. This second
string identifies the characters from the first string that are to be replaced.
strExpr3 is any expression that evaluates to a character string. This third string
specifies the characters to substitute into the first string.
Example
In the character string abcd1234, the characters 123 are replaced by the character
string zz:
REPLACE(‘abcd1234’, ‘123’, ‘zz’)
Result
abcdzz4
RIGHT
This function returns a specified number of characters from the right of a string.
Syntax
RIGHT(strExpr, integer)
Where
strExpr is any expression that evaluates to a character string.
integer is any positive integer that represents the number of characters from
the right of the string to return.
Example
This example returns the three rightmost characters from the character string
123456:
RIGHT(‘123456’, 3)
Result
456
SPACE
Inserts blank spaces.
Syntax
SPACE(integer)
Where
integer is any positive integer that indicates the number of spaces to insert.
SUBSTRING
This function creates a new string starting from a fixed number of characters into
the original string.
Syntax
SUBSTRING(strExpr FROM starting_position)
Where
strExpr is any expression that evaluates to a character string.
starting_position is any positive integer that represents the number of characters
from the start of the left side of the string where the result is to begin.
TRIMBOTH
This function strips specified leading and trailing characters from a character
string.
Syntax
TRIM(BOTH character FROM strExpr)
Where
character is any single character. If you omit this specification (and the
required single quotes), a blank character is used as the default.
strExpr is any expression that evaluates to a character string.
TRIMLEADING
This function strips specified leading characters from a character string.
Syntax
TRIM(LEADING character FROM strExpr)
Where
character is any single character. If you omit this specification (and the
required single quotes), a blank character is used as the default.
strExpr is any expression that evaluates to a character string.
TRIMTRAILING
This function strips specified trailing characters from a character string.
Syntax
TRIM(TRAILING character FROM strExpr)
Where
character is any single character. If you omit this specification (and the
required single quotes), a blank character is used as the default.
strExpr is any expression that evaluates to a character string.
UPPER
This function converts a character string to uppercase.
Syntax
UPPER(strExpr)
Where
strExpr is any expression that evaluates to a character string.
