Using SQL Functions

Using SQL Functions

Function must be entered in escaped ODBC syntax. The functions are entered in the form
{fn function([parm_1[,parm_n]])}.

For example:

select LAST_NAME, FIRST_NAME,
{fn CONCAT(FIRST_NAME,{fn CONCAT(" ",LAST_NAME)})}
from CUSTOMER
where {fn LEFT(LAST_NAME,1)}="A"

Function
Desciption

String Functions

ASCII
Returns the ASCII code value of the leftmost character of string_exp as an integer.
{fn ASCII(string_exp)}

CHAR
Returns a Character from the value of code (0 to 255).
{fn CHAR(code)}

CHAR_LENGTH
Returns the Length of the Character String.
{fn CHAR_LENGTH(string_exp)}

CHARACTER_LENGTH
Returns the Length of the Character String.
{fn CHARACTER_LENGTH(string_exp)}

CONCAT
Returns a Character String that consists of the two strings passed.
{fn CONCAT(string_exp1, string_exp2)}

INSERT
Returns a character string where length characters have been deleted from string_exp1 beginning at start and where string_exp2 has been inserted into string_exp1, beginning at start.
{fn INSERT(string_exp1, start, length, string_exp2)}

LCASE
Returns a string consisting only of lower case characters.
{fn LCASE(string_exp)}

LEFT
Returns the number of characters requested from the left side of the given string.
{fn LEFT(string_exp,count)}

LENGTH
Returns the Length of the Character String.
{fn LENGTH(string_exp)}

LOCATE
Returns the position of a substring within a string.
{fn LEFT (string_exp1,string_exp2[,start])}

LTRIM
Returns a Character String except for any spaces on the left.
{fn LTRIM(string_exp)}

OCTET_LENGTH
Returns the Length in bytes of the value.
{fn OCTET_LENGTH(string_exp)}

REPEAT
Returns a given character the requested number of times.
{fn REPEAT(string_exp,count)}

REPLACE
Search str_exp1 for occurrences of str_exp2 and replace with str_exp3.
{fn LTRIM(str_exp1,str_exp2,str_exp3)}

RIGHT
Returns the rightmost count characters of string_exp. Returns the number of characters requested from the left side of the given string.
{fn RIGHT(string_exp,count)}

RTRIM
Returns the characters of string_exp with trailing blanks removed.
{fn LTRIM(string_exp)}

SPACE
Returns a character string consisting of count spaces. Returns the number of characters requested from the left side of the given string.
{fn SPACE(count)}

SUBSTRING
Extracts one or more characters from a string. Returns the number of characters requested from the left side of the given string.
{fn SUBSTRING(string_exp,start,length)}

UCASE
Converts strings to uppercase. Returns the number of characters requested from the left side of the given string.
{fn UCASE(string_exp)}

Numeric Functions

ABS
Returns the absolute value of numeric_exp.
{fn ABS(numeric_exp)}

CEILING
Returns the smallest integer greater than or equal to numeric_exp. The return value is of the same data type as the input parameter.
{fn CEILING(numeric_exp)}

FLOOR
Rounds a number down to the nearest (smallest) whole number.
{fn FLOOR(numeric_exp)}

MOD
Returns the remainder (modulus) of integer_exp1 divided by integer_exp2.
{fn MOD(integer_exp1,integer_exp2)}

ROUND
Rounds a number (value1) down to the number of decimal digits specified in value2.
{fn ROUND(value1,value2)}

SIGN
Returns a value indicating the sign of the provided value.
{fn SIGN(value)}

Date Functions

CURRENT_DATE
Returns the current host system date.
{fn CURRENT_DATE( )}

CURDATE
Returns the current host system date.
{fn CURDATE( )}

DAYOFMONTH
Returns a number that consists of the Day portion of a given date.
{fn DAYOFMONTH(date_exp)}

MONTH
Returns a number that consists of the Month portion of a given date. Returns a number that consists of the Day portion of a given date.
{fn MONTH(date_exp)}

YEAR
Returns a number that consists of the Year portion of a given date. Returns a number that consists of the Day portion of a given date.
{fn YEAR(date_exp)}

Misc Functions

IS_NULL
Returns true if the value is NULL.
{fn IS_NULL(value)}

IS_NUMERIC
Returns true if the value represents a number.
{fn IS_NUMERIC(value)}

COALESCE
Returns the first non-null value from the list provided. Used in joins that can return NULL values.
{fn COALESCE(value1,value2)}

DECODE
Provides an IF THEN ELSE structure in the form,
if (column==test)then value1 else value2.
{fn DECODE(column,test,value1,value2)}
http://www.minisoft.com/pages/middleware/odbc32/pages/odbcae.htm

posted on 2009-10-29 14:26  ★金★  阅读(273)  评论(0编辑  收藏  举报

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