| Oracle® Database Lite SQL Reference Release 10.3 Part Number E12092-02 |
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View PDF |
| Oracle® Database Lite SQL Reference Release 10.3 Part Number E12092-02 |
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|
View PDF |
This document discusses SQL functions used with Oracle Database Lite. Topics include:
This section lists the different types of SQL functions.The "SQL Functions Overview" provides an explanation of each function.
SQL Function Types
| Number Function | SQL Types |
|---|---|
| CEIL | ROUND - Number Function |
| FLOOR | TRUNC |
| MOD |
| Character Function | SQL Types |
|---|---|
| CHR | ROUND - Date Function |
| CONCAT | SUBSTR |
| INITCAP | SUBSTRB |
| LCASE See LOWER | TRANSLATE |
| LOWER | TRIM |
| LPAD | UCASE See UPPER |
| LTRIM | UPPER |
| REPLACE | USER |
| RPAD | |
| Character Functions | Returning Number Values |
|---|---|
| ASCII | LENGTH |
| BIT_LENGTH (See LENGTH) | LENGTHB |
| CHAR_LENGTH (See LENGTH) | OCTET_LENGTH (See LENGTH) |
| INSTR | POSITION |
| INSTRB |
SQL functions are similar to SQL operators in that both manipulate data items and both return a result. SQL functions differ from SQL operators in the format in which they appear with their arguments. The SQL function format enables functions to operate with zero, one, or more arguments.
function(argument1, argument2, ...) alias
If passed an argument whose datatype differs from an expected datatype, most functions perform an implicit datatype conversion on the argument before execution. If passed a null value, most functions return a null value.
SQL functions are used exclusively with SQL commands within SQL statements. There are two general types of SQL functions: single row (or scalar) functions and aggregate functions. These two types differ in the number of database rows on which they act. A single row function returns a value based on a single row in a query, whereas an aggregate function returns a value based on all the rows in a query.
Single row SQL functions can appear in select lists (except in SELECT statements that contain a GROUP BY clause) and WHERE clauses.
Aggregate functions are the set functions: AVG, MIN, MAX, SUM, and COUNT. You must provide them with an alias that can be used by the GROUP BY function.
Most functions have an SQL form and an ODBC form that can differ slightly in functionality.
Single row character functions accept character input and can return both character and number values.
Some character functions return only number values.
Date functions operate on values of the DATE datatype. All date functions return a value of the DATE datatype, except the MONTHS_BETWEEN function which returns a number.
This section lists Oracle Database Lite SQL functions in alphabetical order and defines each function. The discussion includes:
Syntax
Purpose
Argument and Description
Examples
Usage Notes
ODBC Functionality (where relevant)
Syntax
ADD_MONTHS(d, n)
d, a value of the Date datatype.
n, an integer that represents a number of months.
Purpose
Adds a specified date d to a specified number of months n and returns the resulting date. If the day component of argument d is the last day of the month, or if the resulting month has fewer days than the day component of d, then ADD_MONTHS returns the last day of the resulting month. Otherwise, ADD_MONTHS returns a value that has the same day component as d.
Example
SELECT TO_CHAR(ADD_MONTHS(hiredate,1)),'DD-MM-YYYY' "Next month"FROM emp WHERE ename = 'SMITH'
Returns the following result.
TO_CHAR(ADD_MONTHS(HIREDATE Next month ---------------------------------------- ---------- 1981-01-17 DD-MM-YYYY
Syntax
ASCII(char)
Purpose
Returns the decimal representation in the database character set of the first byte of char. If your database character set is 7-bit ASCII, this function returns an ASCII value.
Example
SELECT ASCII('Q') FROM DUAL;
Returns the following result.
ASCII('Q')
----------
81
Syntax
AVG([DISTINCT | ALL] n)
Purpose
Returns the average value of a column n.
Example 1
SELECT AVG(SAL) FROM EMP;
Returns the following result.
AVG(SAL) --------- 2073.21
Example 2
SELECT {FN AVG (SAL)} FROM EMP;
Returns the following result.
{FNAVG(SAL)}
------------
2073.21
Example 3
SELECT AVG (DISTINCT DEPTNO) FROM EMP;
Returns the following result.
AVG(DISTINCTDEPTNO)
-------------------
20
Example 4
SELECT AVG (ALL DEPTNO) FROM EMP;
Returns the following result.
AVG(ALLDEPTNO)
--------------
22.142
ODBC Function
{FN AVG ([DISTINCT | ALL] n)}
where n is the name of a numeric column.
Syntax
CASE
WHEN condition 1 THEN result 1 WHEN condition 2 THEN result 2 ... WHEN condition n THEN result n ELSE result x
END,
Purpose
Specifies a conditional value using arguments listed in Table 3-1.
Table 3-1 Arguments Used with the CASE Function
| Argument | Description |
|---|---|
|
|
Begins a condition clause. |
|
|
Specifies the condition. |
|
|
Begins a result clause. |
|
|
Specifies the result of the associated condition. |
|
|
An optional clause specifying the result of any value not described in a condition clause. |
|
|
Terminates the case statement. |
Usage Notes
The CASE function specifies conditions and results for a select or update statement. You can use the CASE function to search for data based on specific conditions or to update values based on a condition.
Example
SELECT CASE JOB
WHEN 'PRESIDENT' THEN 'The Honorable' WHEN 'MANAGER' THEN 'The Esteemed' ELSE 'The good'
END,
ENAME FROM EMP;
Returns the following result.
CASEJOBWHEN'PRESI ENAME ----------------- ---------- The Honorable KING The Esteemed BLAKE The Esteemed CLARK The Esteemed JONES The good MARTIN The good ALLEN The good TURNER The good JAMES The good WARD The good FORD The good SMITH The good SCOTT The good ADAMS The good MILLER 14 rows selected.
Syntax
SELECT CAST ( <source_operand > AS <data_type > ) FROM DUAL;
Purpose
Converts data from one type to another type using arguments listed in Table 3-2.
Table 3-2 Arguments Used with the CAST Function
| Argument | Description |
|---|---|
|
<source_operand> |
a value expression or |
|
<data_type> |
the type of target. |
Usage Notes
The table in Figure 3-1 displays the conversion results of source operands to datatypes.
Figure 3-1 Conversion Results of Source Operands and Datatypes
The conversion results of source operands to datatypes are defined in Table 3-3.
Table 3-3 Definitions of Conversion Results and Source Operands
| Result Definitions | Source Operands |
|---|---|
|
EN = exact number |
D = date |
|
C = fixed or variable length character |
TS = timestamp |
|
VC = variable length character |
DT = date-time |
|
T = time |
V = valid |
|
YM = year-month interval |
R = valid with restrictions |
|
AN = approximate numeric |
X = invalid |
|
FC = fixed length character |
If <source_operand> is an exact numeric and <data_type> is an interval, then the interval contains a single date-time field.
If <source_operand> is an interval and <data_type> is an exact numeric, then the interval contains a single date-time field.
If <source_operand> is a character string and <data_type> specifies a character string, then their character repertoire is the same.
If <data_type> is numeric and the result cannot be represented without losing leading significant digits, then the following exception is raised: data-exception, numeric value out of range.
Example 1
SELECT CAST('0' AS INTEGER) FROM DUAL;
Returns the following result.
CAST('0'ASINTEGER)
------------------
0
Example 2
SELECT CAST(0 AS REAL) FROM DUAL;
Returns the following result.
CAST(0ASREAL)
-------------
0
Example 3
SELECT CAST(1E0 AS NUMERIC(12, 2)) FROM DUAL;
Returns the following result.
CAST(1E0ASNUMERIC(12
--------------------
1
Example 4
SELECT CAST(CURRENT_TIMESTAMP AS VARCHAR(30)) FROM DUAL;
Returns the following result.
CAST(CURRENT_TIMESTAMPASVARCH ------------------------------ 1999-04-12 14:53:53
Syntax
CEIL (n)
Purpose
Returns smallest integer greater than or equal to n.
Example
SELECT CEIL(15.7) "Ceiling" FROM DUAL;
Returns the following result.
Ceiling
---------
16
Syntax
CHR (n)
Purpose
Returns the character with the binary equivalent to n in the database character set.
Example
SELECT CHR(68)||CHR(79)||CHR(71) "Dog" FROM DUAL;
Returns the following result.
Dog --- DOG
Syntax
CONCAT(char1, char2)
or
CHAR1 || CHAR2
Purpose
Returns char1 concatenated with char2, where char1 and char2 are string arguments. This function is equivalent to the concatenation operator (||).
Example
This example uses nesting to concatenate three character strings.
SELECT CONCAT( CONCAT(ename, ' is a '), job) "Job" FROM emp WHERE empno = 7900;
Returns the following result.
Job ------------------------- JAMES is a CLERK
ODBC Function
{FN CONCAT (char1, char2)}
Syntax
{ fn CONVERT(value_exp, data_type) }
Purpose
Converts a character string from one character set to another.
The value_exp argument is the value to be converted.
The data_type argument is the name of the character set to which char is converted.
Usage Notes
The common character sets are listed in Table 3-4.
Table 3-4 Common Character Sets Used with the CONVERT Function
| Common Character Sets | |
|---|---|
|
US7ASCII |
WE8ISO8859P1 |
|
WE8DEC |
HP West European Laserjet 8-bit character set |
|
WE8HP |
DEC French 7-bit character set |
|
F7DEC |
IBM West European EBCDIC Code Page 500 |
|
WE8EBCDIC500 |
IBM PC Code Page 850 ISO 8859-1 West European 8-bit character set |
|
WE8PC850 |
ISO 8859-1 West European 8-bit character set |
Example
SELECT {fn CONVERT('Groß', 'US7ASCII') }
"Conversion" FROM DUAL;
Returns the following result.
conversi -------- Groß
Syntax
COUNT([* | [DISTINCT | ALL] expr})
Purpose
Returns the number of rows in the query.
Example 1
SELECT COUNT(*) "Total" FROM emp;
Returns the following result.
Total ---------- 14
Example 2
SELECT COUNT(job) "Count" FROM emp;
Returns the following result.
Count ---------- 14
Example 3
SELECT COUNT(DISTINCT job) "Jobs" FROM emp;
Returns the following result.
Jobs ---------- 5
Example 4
SELECT COUNT (ALL JOB) FROM EMP;
Returns the following result.
COUNT(ALLJOB) -------------
Syntax
{ fn CURDATE ( <value_expression > ) }
Purpose
Returns the current date.
Usage Notes
If you specify expr (expression), this function returns rows where expr is not null. You can count either all rows, or only distinct values of expr.
If you specify the asterisk (*), this function returns all rows, including duplicates and nulls.
Example 1
SELECT {fn CURDATE()} FROM DUAL;
Returns the following result.
{FNCURDATE
-----------
1999-04-12
Example 2
SELECT {fn WEEK({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNWEEK({FNCURDATE()})}
-----------------------
16
Syntax
CURRENT_DATE
Purpose
Returns the current date.
Example
SELECT CURRENT_DATE FROM DUAL;
Returns the following result.
CURRENT_DATE ------------ 1999-04-12
ODBC Function
{fn CURDATE()}
Syntax
CURRENT_TIME
Purpose
Returns the current time.
Example
SELECT CURRENT_TIME FROM DUAL;
Returns the following result.
CURRENT_T --------- 15:54:18
ODBC Function
{fn CURTIME()}
Syntax
CURRENT_TIMESTAMP
Purpose
Returns the current local date and local time as a timestamp value but only displays the current local date by default. You can view current local time information by using CURRENT_TIMESTAMP as a value of the TO_CHAR function and by including a time format. For more information, see Example 2.
Example 1
SELECT CURRENT_TIMESTAMP FROM DUAL;
Returns the following result.
CURRENT_TI --------- 1999-04-12
Example 2
SELECT TO_CHAR (CURRENT_TIMESTAMP, 'HH24:MM:SS, Day, Month, DD, YYYY')FROM DUAL;
Returns the following result.
TO_CHAR(CURRENT_TIMESTAMP ---------------------------------------- 18:04:05, Tuesday , April , 06, 1999
ODBC Function
{fn CURTIME()}
Syntax
{ fn CURTIME ( <value_expression > ) }
Purpose
Returns the current time.
Example 1
SELECT {fn CURTIME()} FROM DUAL;
Returns the following result.
{FNCURTIM
---------
11:09:59
Example 2
SELECT {fn HOUR({fn CURTIME()})} FROM DUAL;
Returns the following result.
{FNHOUR({FNCURTIME()})}
-----------------------
11
Syntax
{ fn DATABASE () }
Purpose
Specifies the name of the database. If you are using ODBC, the DATABASE function returns the name of the current default database file without the .ODB extension.
Usage Notes
A database name function returns the same value as that of SQLGetConnectOption() with the option SQL_CURRENT_QUALIFIER.
Example
The following example returns a result for users connected to the default database.
SELECT {fn DATABASE () } FROM DUAL;
Returns the following result.
{FNDATABASE()}
--------------
POLITE
Syntax
{ fn DAYNAME (date_expr) }
Purpose
Returns the day of the week as a string.
Example
SELECT {fn dayname({fn curdate()})} from dual;
Returns the current day of the week as a string.
Syntax
{ fn DAYOFMONTH ( <value_expression > ) }
Purpose
Returns the day of the month as an integer using arguments listed in Table 3-5.
Table 3-5 Argument Used with the DAYOFMONTH Function
| Argument | Description |
|---|---|
|
<value_expression> |
Date on which the day of the month is computed. The result is between 1 and 31, where 1 represents the first day of the month. |
Example 1
SELECT {fn DAYOFMONTH ({fn CURDATE()})} FROM DUAL;
Returns the following result:
{FNDAYOFMONTH({FNCURDATE()})
----------------------------
12
Example 2
SELECT {fn DAYOFMONTH('1997-07-16')} "DayOfMonth" FROM DUAL;
Returns the following result.
DayOfMonth
----------
16
Syntax
{ fn DAYOFWEEK ( <value_expression > ) }
Purpose
Returns the day of the week as an integer using arguments listed in Table 3-6.
Table 3-6 Argument Used with the DAYOFWEEK Function
| Argument | Description |
|---|---|
|
<value_expression> |
Date on which the day of the week is computed. The result is between 1 and 7, where 1 represents Sunday. |
Example 1
SELECT {fn DAYOFWEEK ({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNDAYOFWEEK({FNCURDATE()})}
----------------------------
2
Example 2
SELECT {fn DAYOFWEEK('1997-07-16')} "DayOfWeek" FROM DUAL;
Returns the following result.
DayOfWeek ------------------ 4
Syntax
{ fn DAYOFYEAR ( <value_expression > ) }
Purpose
Returns the day of the year as an integer using arguments listed in Table 3-7.
Table 3-7 Argument Used with the DAYOFYEAR Function
| Argument | Description |
|---|---|
|
<value_expression> |
A date on which the day of the year is computed. The result is between 1 and 366. |
Example 1
SELECT {fn DAYOFYEAR ({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNDAYOFYEAR({FNCURDATE()})}
----------------------------
102
Example 2
SELECT {fn DAYOFYEAR('1997-07-16')} "DAYOFYEAR" FROM DUAL;
Returns the following result.
DayOfYear --------- 197
Syntax
DECODE (expr, search, result [, search, result...] [,default])
Purpose
Search for an expression's values and then evaluate them in terms of a specified result.
Usage Notes
To evaluate an expression, Oracle Database Lite compares the expression to each search value one by one. If the expression is equal to a search, Oracle Database Lite returns the corresponding result. If no match is found, Oracle Database Lite returns default, or, if default is omitted, returns null. If the expression and search contain character data, Oracle Database Lite compares them using non-padded comparison semantics.
The search, result, and default values can be derived from expressions. Oracle Database Lite evaluates each search value only before comparing it to the expression, rather than evaluating all search values before comparing any of them with the expression. Consequently, Oracle Database Lite never evaluates a search if a previous search is equal to the expression.
Oracle Database Lite automatically converts the expression and each search value to the datatype of the first search value before making comparisons. Oracle Database Lite automatically converts the return value to the same datatype as the first result. If the first result has the datatype CHAR or if the first result is null, then Oracle Database Lite converts the return value to the datatype VARCHAR2.
In a DECODE expression, Oracle Database Lite considers two nulls to be equivalent. If the expression is null, Oracle Database Lite returns the result of the first search that is also null.
The maximum number of components in the DECODE expression, including the expression, searches, results, and default is 255.
Example 1
The following expression decodes the DEPTNO column in the DEPT table. If DEPTNO is 10, the expression evaluates to 'ACCOUNTING'; if DEPTNO is 20, it evaluates to 'RESEARCH'; and so on. If DEPTNO is not 10, 20, 30, or 40, the expression returns 'NONE'.
DECODE (deptno, 10, 'ACCOUNTING', 20, 'RESEARCH', 30, 'SALES', 40, 'OPERATIONS', 'NONE')
Example 2
The following example uses the DECODE clause in a SELECT statement.
SELECT DECODE (deptno, 10, 'ACCOUNTING', 20, 'RESEARCH', 30, 'SALES', 40, 'OPERATIONS', 'NONE') FROM DEPT;
Returns the following result.
DECODE(DEP ---------- ACCOUNTING RESEARCH SALES OPERATIONS
Syntax
EXTRACT (extract-field FROM extract source)
Purpose
Returns information from the i portion of the extract-source. The extract-source argument contains date-time or interval expressions. The extract-field argument contains one of the following keywords: YEAR, MONTH, DAY, HOUR, MINUTE, or SECOND.
The precision of the returned value is defined in implementation. The scale is 0 unless SECOND is specified. When SECOND is specified, the scale is not less than the fractional seconds precision of the extract-source field.
Example 1
SELECT EXTRACT (DAY FROM '06-15-1966') FROM DUAL;
Returns the following result.
EXTRACT(DAY
-----------
15
Example 2
SELECT EXTRACT (YEAR FROM {FN CURDATE()}) FROM DUAL;
Returns the following result.
EXTRACT(YEAR
------------
1999
Syntax
FLOOR (n)
Purpose
Returns largest integer equal to or less than n.
Example
SELECT FLOOR(15.7) "Floor" FROM DUAL;
Returns the following result.
Floor
---------
15
Syntax
GREATEST(expr [,expr] ...)
Purpose
Returns the greatest of the list of exprs (expressions). All exprs after the first are implicitly converted to the datatype of the first exprs before the comparison. Oracle Database Lite compares the exprs using non padded comparison semantics. Character comparison is based on the value of the character in the database character set. One character is greater than another if it has a higher value. If the value returned by this function is character data, its datatype is always VARCHAR2.
Example
SELECT GREATEST('HARRY','HARRIOT','HAROLD') "GREATEST" FROM DUAL;
Returns the following result.
GREATEST -------- HARRY
Syntax
HOUR (time_exp)
Purpose
Returns the hour as an integer value in the range of 0-23.
Example 1
SELECT {FN HOUR ('14:03:01')} FROM DUAL;
Returns the following result.
{FNHOUR('14:03:01')}
--------------------
14
Example 2
SELECT {fn HOUR({fn CURTIME()})} FROM DUAL;
Returns the following result.
{FNHOUR({FNCURTIME()})}
-----------------------
11
Syntax
INITCAP(char)
Purpose
Returns char, with the first letter of each word in uppercase, all other letters in lowercase. Words are delimited by white space or characters that are not alphanumeric.
Example
SELECT INITCAP('the soap') "Capitals" FROM DUAL;
Returns the following result.
Capitals -------- The Soap
Syntax
INSTR(char1, char2, [, n [, m ]])
Purpose
Searches the string argument char1, beginning with its nth character, for the mth occurrence of string argument char2, where m and n are numeric arguments. Returns the position in char1 of the first character of this occurrence.
Usage Notes
If n is negative, INSTR counts and searches backward from the end of char1. The value of m must be positive. The default values of both n and m are 1, meaning that INSTR begins searching at the first character of char1 for the first occurrence of char2. The return value is relative to the beginning of char1, regardless of the value of n, and is expressed in characters. If the search is unsuccessful (if char2 does not appear m times after the nth character of char1), the return value is 0. For additional information, see the syntax for the POSITION function.
Example
SELECT INSTR('CORPORATE FLOOR','OR',3,2) "Instring" FROM DUAL;
Returns the following result.
Instring
---------
14
Syntax
INSTRB(char1, char2, [, n [, m ]])
Purpose
Searches the string argument char1, beginning with its nth byte, for the mth occurrence of string argument char2, where m and n are numeric arguments. Returns the position in char1 of the first byte of this occurrence. The same as INSTR except that n and the function's return value are expressed in bytes rather than characters. For a single-byte database character set, INSTRB is equivalent to INSTR.
Example
SELECT INSTRB('CORPORATE FLOOR','OR',5,2) "Instring in bytes" FROM DUAL;
Returns the following result.
Instring in bytes
-----------------
14
Syntax
INTERVAL (datetime values)
Purpose
Subtracts one datetime from another and generates the result. When you add or subtract one interval from another, the result is always another interval. You can multiply or divide an interval by a numeric constant.
Example 1
SELECT CURRENT_DATE - INTERVAL '8' MONTH FROM DUAL;
Returns the following result.
CURRENT_DATE-INTERVAL --------------------- 1998-08-09
Example 2
SELECT TO_CHAR (INTERVAL '6' DAY * 3) FROM DUAL;
Returns the following result.
TO_CHAR(INTERVAL'6'DAY*3) ------------------------- 18
Syntax
LAST_DAY(d)
Purpose
Returns a date that represents the last day of the month in which date d occurs.
Usage Notes
You can use this function to determine how many days are left in the current month.
Example 1
SELECT LAST_DAY (SYSDATE) FROM DUAL;
Returns the following result.
LAST_DAY ---------- 1999-04-30
Example 2
SELECT SYSDATE, LAST_DAY(SYSDATE) "Last", LAST_DAY(SYSDATE) - SYSDATE "Days Left" FROM DUAL;
Returns the following result.
{FNNOW()} Last Days Left
---------- ---------- ---------
1999-04-12 1999-04-30 18
Syntax
LEAST(expr [,expr] ...)
Purpose
Returns the least of the list of exprs (expressions). All exprs after the first are implicitly converted to the datatype of the first exprs before the comparison. Oracle Database Lite compares the exprs using non-padded comparison semantics. Character comparison is based on the value of the character in the database character set. One character is less than another if it has a lower value. If the value returned by this function is character data, its datatype is always VARCHAR2.
Example
SELECT LEAST('HARRY','HARRIOT','HAROLD') "LEAST" FROM DUAL;
Returns the following result.
LEAST ------- HAROLD
Syntax
LENGTH (char) {fn LENGTH(char)} BIT_LENGTH (char) CHAR_LENGTH (char) OCTET_LENGTH (char)
LENGTH returns the number of characters in char. BIT_LENGTH, CHAR_LENGTH, and OCTET_LENGTH return the length of char in bits, characters, or octets, respectively.
Purpose
Returns the length in characters of the string argument char. If char has the datatype CHAR, the length includes all trailing blanks. If char is null, it returns null.
Usage Notes
BIT_LENGTH, CHAR_LENGTH, and OCTET_LENGTH are SQL-92 functions. CHAR_LENGTH is the same as LENGTH, and OCTET_LENGTH is the same as LENGTHB.
Example
SELECT LENGTH('CANDIDE') "Length in characters" FROM DUAL;
Returns the following result.
Length in characters
--------------------
7
Syntax
LENGTHB(char) {fn LENGTHB(char)}
Purpose
Returns the length in bytes of the string argument char. If char is null, it returns null. For a single-byte database character set, LENGTHB is equivalent to LENGTH.
Example
SELECT LENGTHB('CANDIDE') "Length in bytes" FROM DUAL;
Returns the following result.
Length in bytes
---------------
7
Syntax
LOCATE (string_exp1, string_exp2[,start])
Purpose
Returns the starting position of the first occurrence of string_exp1 within the first character position of string_exp2. You can use the start value to specify a search location other than the first character position of string_exp2.
Example 1
The following example selects the starting position of the character 'R' in the string expression 'TURNER' for every row of the EMP table.
SELECT {FN LOCATE ('R', 'TURNER')} FROM EMP ENAME;
Returns the following result.
{FNLOCATE('R'
-------------
3
3
3
3
3
3
3
3
3
3
3
3
3
3
14 rows selected.
Example 2
The following example selects the starting position of the character 'R' in the string expression 'TURNER' and starts its search at the fourth character in 'TURNER'. The example displays the results found for every occurrence of 'TURNER' in every row of the EMP table.
SELECT {FN LOCATE ('R', 'TURNER',4)} FROM EMP ENAME;
Returns the following result.
{FNLOCATE('R'
-------------
6
6
6
6
6
6
6
6
6
6
6
6
6
6
14 rows selected.
Syntax
LOWER(char)
Purpose
Returns a string argument char, with all its letters in lowercase. The return value has the same datatype as char, either CHAR or VARCHAR2.
Example
SELECT LOWER('LOWER') FROM DUAL;
Returns the following result.
LOWER ----- lower
ODBC Function
{fn LCASE (char)}
Syntax
LPAD(char1,n [,char2])
Purpose
Returns char1, left-padded to length n with the sequence of characters in char2; char2 defaults to a single blank. If char1 is longer than n, this function returns the portion of char1 that fits in n.
The argument n is the total length of the return value as it is displayed on your terminal screen. In most character sets, this is also the number of characters in the return value. However, in some multi-byte character sets, the display length of a character string can differ from the number of characters in the string.
Example
SELECT LPAD('Page1',15,'*.') "LPAD example" FROM DUAL;
Returns the following result.
LPAD example ----------------- *.*.*.*.*.Page1
Syntax
LTRIM(char [, set])
Purpose
Returns the string argument char, with its left-most characters removed up to the first character which is not in the string argument set, which defaults to (a single space).
Example
SELECT LTRIM ('xyxXxyLAST WORD','xy') "LTRIM example" FROM DUAL;
Returns the following result.
LTRIM example --------------- XxyLAST WORD
ODBC Function
{fn LTRIM (char) } (trims leading blanks)
Syntax
MAX([DISTINCT | ALL] expr)
Purpose
Returns the maximum value of an expression specified by the argument expr.
Example
SELECT MAX(SAL) FROM EMP;
Returns the following result.
MAX(SAL) --------- 5000
Syntax
MIN([DISTINCT | ALL] expr)
Purpose
Returns the minimum value of an expression specified by the argument expr.
Example
SELECT MIN(SAL), MAX(SAL) FROM EMP;
Returns the following result.
MIN(SAL)
---------
800
Syntax
MINUTE (time_exp)
Purpose
Returns the minute as an integer value in the range of 0-59.
Example 1
SELECT {FN MINUTE ('14:03:01')} FROM DUAL;
Returns the following result.
{FNMINUTE('14:03:01')}
----------------------
3
Example 2
SELECT {fn MINUTE({fn CURTIME()})} FROM DUAL;
Returns the following result.
{FNMINUTE({FNCURTIME()})}
-------------------------
23
Syntax
MOD (m,n)
Purpose
Returns the remainder of m divided by n. Returns m if n is 0.
Example
SELECT MOD (26,11) "ABLOMOV" FROM DUAL;
Returns the following result.
ABLOMOV
---------
4
Syntax
MONTH (date_exp)
Purpose
Returns the month as an integer value in the range of 1-12.
Example 1
SELECT {FN MONTH ('06-15-1966')} FROM DUAL;
Returns the following result.
{FNMONTH('06-15-1966')}
-----------------------
6
Example 2
SELECT {fn MONTH({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNMONTH({FNCURDATE()})}
------------------------
4
Syntax
{ fn MONTHNAME (date_exp) }
Purpose
Returns the name of the month as a string.
Example
select {fn monthname({fn curdate()})} from dual;
Returns the current month of the year as a string.
Syntax
MONTHS_BETWEEN(d1, d2 )
Purpose
Returns number of months between dates d1 and d2. If d1 is later than d2, result is positive; if earlier, negative. If d1 and d2 are either the same days of the month or both last days of months, the result is always an integer. Otherwise, Oracle Database Lite calculates the fractional portion of the result based on a 31-day month and considers the difference in time components of d1 and d2.
Example
SELECT MONTHS_BETWEEN(
TO_DATE('02-02-1995','MM-DD-YYYY'),
TO_DATE('01-01-1995','MM-DD-YYYY') ) "Months"
FROM DUAL;
Returns the following result.
Months --------- 1.0322581
Syntax
NEXT_DAY(d, char)
Purpose
Returns the date of the first weekday named by char that is later than the date d. The argument char must be a day of the week in your session's date language. The return value has the same hours, minutes, and seconds component as the argument d.
Example
SELECT NEXT_DAY('15-MAR-92','TUESDAY') "NEXT DAY" FROM DUAL;
Returns the following result.
NEXT DAY ---------- 1992-03-17
Syntax
NOW
Purpose
Returns the current local date and local time as a timestamp value but only displays the current local date by default. You can view current local time information by using NOW as a value of the TO_CHAR function and by including a time format. For more information, see Example 2.
Example 1
SELECT {FN NOW()} FROM DUAL;
Returns the following result.
{FNNOW()}
----------
1999-04-07
Example 2
SELECT TO_CHAR ({fn NOW ('YYYY, Month, DD, HH24:MM:SS')}) FROM DUAL;
Returns the following result.
TO_CHAR({FNNOW('YYYY
----------------------------------------
1999-04-07 12:55:31
Syntax
NVL(expr1, expr2)
Purpose
If expr1 is null, returns expr2; if expr1 is not null, returns expr1. The arguments expr1 and expr2 must be of the same datatype.
Example 1
SELECT ename, NVL(TO_CHAR(COMM),'NOT APPLICABLE') "COMMISSION" FROM emp WHERE deptno = 30;
Returns the following result.
ENAME COMMISSION ---------- ---------------- BLAKE NOT APPLICABLE MARTIN 1400.00 ALLEN 300.00 TURNER .00 JAMES NOT APPLICABLE WARD 500.00 6 rows selected.
Example 2
SELECT {fn IFNULL(Emp.Ename, 'Unknown')},
NVL (Emp.comm, 0) FROM EMP;
Returns the following result.
{FNIFNULL( 'UNKNOWN')}
---------- -----------
KING 0
BLAKE 0
CLARK 0
JONES 0
MARTIN 1400
ALLEN 300
TURNER 0
JAMES 0
WARD 500
FORD 0
SMITH 0
SCOTT 0
ADAMS 0
MILLER 0
14 rows selected.
Example 3
SELECT sal+NVL(comm, 0) FROM EMP;
Returns the following result.
SAL+NVL(COMM
------------
5000
2850
2450
2975
2650
1900
1500
950
1750
3000
800
3000
1100
1300
14 rows selected.
ODBC Function
{fn IFNULL (expr1, expr2)}
Syntax
POSITION ( <substring_value_expression> IN <value_expression> )
The arguments for the POSITION function are listed in Table 3-8.
Table 3-8 Arguments Used with the POSITION Function
| Argument | Description |
|---|---|
|
<value_expression> |
a source string to search in. |
|
<substring_value_expression> |
a sub-string to search for. |
|
<start_len_cnt> |
the starting position for the search |
Purpose
Returns the starting position of the first occurrence of a sub-string in a string.
Usage Notes
If the length of <substring_value_expression> is 0, the result is null. If <substring_value_expression> occurs in <value_expression>, the result is the position of the first character of <substring_value_expression>. Otherwise, the result is 0. If <start_len_cnt> is omitted, the function starts the search from position 1. For additional information, see the INSTR and INSTRB functions.
Example
SELECT POSITION ('CAT' IN 'CATCH') FROM DUAL;
Returns the following result.
POSITION('CAT'IN'CATCH')
------------------------
1
ODBC Function
{fn LOCATE ( <substring_value_expression> ,
<value_expression>[, <start_len_cnt> ] ) }
Syntax
{ fn QUARTER ( <value_expression> ) }
The arguments for the QUARTER function are listed in Table 3-9.
Table 3-9 Arguments Used with the QUARTER Function
| Argument | Description |
|---|---|
|
<value_expression> |
A date on which the quarter is computed. The result is between 1 and 4, where 1 represents January 1 through March 31. |
Purpose
Returns the quarter of a date as an integer.
Example
SELECT {fn QUARTER ({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNQUARTER({FNCURDATE()})}
--------------------------
2
Syntax
REPLACE(char, search_string [, replacement_string])
Purpose
Returns char with every occurrence of search_string replaced with replacement_string, where char, search_string, and replacement_string are string arguments.
Usage Notes
If replacement_string is omitted or null, all occurrences of search_string are removed. If search_string is null, then char is returned. This function provides a super-set of the functionality provided by the TRANSLATE function. TRANSLATE provides single character, one to one, and substitution functions. REPLACE enables you to substitute one string for another as well as to remove character strings.
Example
SELECT REPLACE('JACK and JUE','J','BL') "Changes" FROM DUAL;
Returns the following result.
Changes --------------- BLACK and BLUE
Syntax
ROUND(d [,fmt])
The format models to be used with the ROUND (and TRUNC) date function, and the units to which it rounds dates are listed in Table 3-10. The default model, DD, returns the date rounded to the day with a time of midnight.
Table 3-10 The Format Models with the ROUND Date Function
| Formal Model | Rounding Unit |
|---|---|
|
|
Century |
|
|
Year (rounds up on July 1) |
|
|
ISO Year |
|
|
Quarter (rounds up in the sixteenth day of the second month of the quarter) |
|
|
Month (rounds up on the sixteenth day) |
|
|
Same day of the week as the first day of the year |
|
|
Same day of the week as the first day of the ISO year |
|
|
Same day of the week as the first day of the month |
|
|
Day |
|
|
Starting day of the week. |
|
|
Hour |
|
|
Minute |
Purpose
Returns d rounded to the unit specified by the format model fmt. If you omit fmt, d is rounded to the nearest day.
Example
SELECT ROUND(TO_DATE('27-OCT-92'),'YEAR')
"FIRST OF THE YEAR" FROM DUAL;
Returns the following result.
FIRST OF --------- 1993-01-0
Syntax
ROUND(n [,m ])
Purpose
Returns n rounded to m places to the right of the decimal point; if m is omitted, to 0 places. m can be negative to round off digits left of the decimal point. m must be an integer.
Example 1
SELECT ROUND (54.339, 2) FROM DUAL;
Returns the following result.
ROUND(54.339 ------------ 54.34
Syntax
RPAD(char1,n [,char2 ])
Purpose
Returns char1, right-padded to length n with char2 replicated as many times as necessary; char2 defaults to a single blank. If char1 is longer than n, this function returns the portion of char1 that fits in n.
The argument n is the total length of the return value as it is displayed on your terminal screen. In most character sets, this is also the number of characters in the return value. However, in some multi-byte character sets, the display length of a character string can differ from the number of characters in the string.
Example
SELECT RPAD('ename',12,'ab') "RPAD example"
FROM emp
WHERE ename = 'TURNER';
Returns the following result.
RPAD example ------------- enameabababa
Syntax
RTRIM(char [,set])
Purpose
Returns the string argument char, with its right-most characters removed following the last character which is not in the string argument set. This defaults to ' ' (a single space).
Example 1
SELECT RTRIM ('TURNERyxXxy', 'xy') "RTRIM example" FROM DUAL;
Returns the following result.
RTRIM examp ----------- TURNERyxX
Example 2
SELECT {fn RTRIM ('TURNERyxXxy', 'xy')} FROM DUAL;
Returns the following result.
{{FNRTRIM('T
-----------
TURNERyxX
ODBC Function
{fn RTRIM (char)} (trims leading blanks)
Syntax
SECOND (time_exp)
Purpose
Returns the second as an integer value in the range of 0-59.
Example 1
SELECT {FN SECOND ('14:03:01')} FROM DUAL;
Returns the following result.
{FNSECOND('14:03:01')}
----------------------
1
Example 2
SELECT {fn SECOND({fn CURTIME()})} FROM DUAL;
Returns the following result.
{FNSECOND({FNCURTIME()})}
-------------------------
59
Syntax
STDDEV([DISTINCT|ALL] x)
Purpose
Returns the standard deviation of x, a number. Oracle Database Lite calculates the standard deviation as the square root of the variance defined for the VARIANCE group function.
Example
SELECT STDDEV(sal) "Deviation" FROM emp;
Returns the following result.
Deviation --------- 1182.5032
Syntax
SUBSTR(char, m [, n ])
Purpose
Returns a portion of the string argument char, beginning with the character at position m and n characters long.
Usage Notes
If m is positive, SUBSTR counts from the beginning of char to find the first character. If m is negative, SUBSTR counts backwards from the end of char. The value m cannot be 0. If n is omitted, SUBSTR returns all characters to the end of char. The value n cannot be less than 1.
Example
SELECT SUBSTR('ABCDEFG',3,4) "Subs" FROM DUAL;
Returns the following result.
Subs ---- CDEF
Syntax
SUBSTRB(char, m [,n])
Purpose
Returns a portion of the string argument char, beginning with the byte at position m and n bytes long. The same as SUBSTR, except that the arguments m and n specify bytes rather than characters. For a single-byte database character set, SUBSTRB is equivalent to SUBSTR.
Example
SELECT SUBSTRB('ABCDEFG',5,4) "Substring with bytes" FROM DUAL;
Returns the following result.
Substring with bytes -------------------- EFG
Syntax
SUM([DISTINCT | ALL] n)
Purpose
Returns the sum of values of n.
Example
SELECT deptno, SUM(sal) TotalSalary FROM emp GROUP BY deptno;
Returns the following result.
DEPTNO TOTALSALARY
--------- -----------
10 8750
20 10875
30 9400
Syntax
SYSDATE
Purpose
Returns the current date and time. Requires no arguments.
Usage Notes
You cannot use this function in the condition of the Oracle Database Lite DATA type column. You can only use the time in a TIME column, and both date and time in a TIMESTAMP column.
Example
SELECT TO_CHAR(SYSDATE, 'MM-DD-YYYY HH24:MI:SS') NOW FROM DUAL;
Returns the following result.
NOW ------------------- 04-12-1999 19:13:48
Syntax
{fn TIMESTAMPADD (<interval>, <value_exp1 >, <value_exp2 >)}
<value_exp1 > + <value_exp2 >
The arguments for the TIMESTAMPADD function are listed in Table 3-11.
Table 3-11 Arguments Used with the TIMESTAMPADD Function
| Argument | Description |
|---|---|
|
<interval> |
Specifies the unit of the second operand, <value_exp1>. The following keywords are valid values for intervals.
|
|
<value_exp1> |
an integer |
|
<value_exp2> |
a timestamp |
|
<value_expression> |
an operand |
Purpose
Adds a date and time value to the current timestamp.
Example
The following example adds one day to the current timestamp for 1999-04-13.
SELECT {fn TIMESTAMPADD (SQL_TSI_DAY, 1, {fn NOW()})} FROM DUAL;
Returns the following result.
{FNTIMESTA
----------
1999-04-14
Syntax
{fn TIMESTAMPDIFF (<interval>, <value_exp1 >, <value_exp2 >)}
<value_expression > - <value_expression >
The arguments for the TIMESTAMPDIFF function are listed in Table 3-12.
Table 3-12 Arguments Used with the TIMESTAMPDIFF Function
| Argument | Description |
|---|---|
|
<interval> |
specifies the unit of the second operand, <value_exp1>. The following keywords are valid values for intervals:
|
|
<value_exp1> |
an integer |
|
<value_exp2> |
a timestamp |
|
<value_expression> |
an operand |
Purpose
Calculates the difference between two timestamp values using a specified interval.
Example 1
SELECT {fn TIMESTAMPDIFF (SQL_TSI_DAY, {fn CURDATE()}, '1998-12-09')} FROM DUAL;
Returns the following result.
{FNTIMESTAMPDIFF(SQL_TSI_DAY
----------------------------
-125
Example 2
SELECT ENAME, {fn TIMESTAMPDIFF (SQL_TSI_YEAR, {fn CURDATE()},HIREDATE)} FROM EMP;
Returns the following result.
ENAME {FNTIMESTAMPDIFF(SQL_TSI_YEA
---------- ----------------------------
KING -17
BLAKE -17
CLARK -17
JONES -18
MARTIN -17
ALLEN -18
TURNER -17
JAMES -17
WARD -18
FORD -17
SMITH -18
SCOTT -16
ADAMS -16
MILLER -17
14 rows selected.
Syntax for Dates
TO_CHAR(d [, fmt])
Syntax for Numbers
TO_CHAR(n [, fmt])
Purpose
Converts a date or number to a value of the VARCHAR2 datatype, using the optional format fmt using arguments listed in Table 3-13.
Table 3-13 Arguments Used with the TO_CHAR Function
| Argument | Description |
|---|---|
|
d |
date column or |
|
fmt |
format model. The format model is fully described in the Oracle Database SQL Reference. |
|
n |
number column or literal |
Usage Notes
If you omit fmt, the argument d or n is converted to a VARCHAR2 value. For dates, the argument d is returned in the default date format. For numbers, the argument n is converted to a value exactly long enough to hold its significant digits.
Date literals must be preceded by the DATE keyword when used as arguments to TO_CHAR.
You can specify a default date format for all databases on your computer by setting the NLS_DATE_FORMAT parameter in the POLITE.INI file. See Appendix E, "POLITE.INI Parameters" in the Oracle Database Lite Administration and Deployment Guide for more information on setting the NLS_DATE_FORMAT parameter in the POLITE.INI file.
Example
SELECT TO_CHAR (SYSDATE, 'Day, Month, DD, YYYY')"TO_CHAR example" FROM DUAL;
Returns the following result.
TO_CHAR example -------------------------------- Saturday , May , 22, 1999
Syntax
TO_DATE(char [, fmt ])
Purpose
Converts the character string argument char to a value of the DATE datatype. The fmt argument is a date format specifying the format of char.
Example
SELECT TO_DATE('January 26, 1996, 12:38 A.M.', 'Month dd YYYY HH:MI A.M.') FROM DUAL;
Returns the following result.
TO_CHAR(TO_DATE('JANUARY26
----------------------------------------
1996-01-26 12:38:00
Syntax
TO_NUMBER(char [, fmt ])
Purpose
Converts the string argument char that contains a number in the format specified by the optional format model fmt, to a return value of the NUMBER datatype.
Usage Notes
For information about date and number formats, see Formats.
Do not use the TO_DATE function with a DATE value for the char argument.
The returned DATE value can have a different century value than the original char, depending on fmt or the default date format.
Dates in the Oracle format (such as 06-JUN-85 and 6-JUN-1985), the SQL-92 format (such as 1989-02-28), or the format specified by the NLS_DATE_FORMAT parameter are converted automatically when inserted into a date column.
You can specify a default date format for all databases on your computer by setting the NLS_DATE_FORMAT parameter in the POLITE.INI file. See the Appendix E, "POLITE.INI Parameters" in the Oracle Database Lite Administration and Deployment Guide for more information on setting the NLS_DATE_FORMAT parameter in the POLITE.INI file.
Example
The following example updates the salary of an employee named Blake according to the value specified in the TO_NUMBER function. In this example, you first view Blake's salary. Then, update Blake's salary and view it again.
SELECT * FROM EMP WHERE ENAME = 'BLAKE';
Returns the following result.
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
--------- ---------- --------- --------- --------- --------- --------- ---------
7698 BLAKE MANAGER 7839 1981-05-0 2850 30
UPDATE EMP SET SAL = SAL + TO_NUMBER('100.52','9,999.99') WHERE ENAME = 'BLAKE';
Returns the following result.
1 row updated. SELECT * FROM EMP WHERE ENAME = 'BLAKE';
Returns the following result.
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
--------- ---------- --------- --------- --------- --------- --------- ---------
7698 BLAKE MANAGER 7839 1981-05-0 2950.52 30
Syntax
TRANSLATE(char, from, to)
Purpose
Returns char with all occurrences of each character in from replaced by its corresponding character in to, where char, from, and to are string arguments.
Usage Notes
Characters in char that are not in from are not replaced.
The argument from can contain more characters than to. In this case, the extra characters at the end of from have no corresponding characters in to. If these extra characters appear in char, they are removed from the return value.
You cannot use an empty string for to to remove from the return value all characters in from. TRANSLATE interprets the empty string as null, and if this function has a null argument, it returns null.
Example
SELECT TRANSLATE('2KRW229', '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ',
'9999999999XXXXXXXXXXXXXXXXXXXXXXXXXX') "Licence" FROM DUAL;
Returns the following result.
Licence ------- 9XXX999
Syntax
TRIM( [[<trim_spec >] char ] FROM ] string )
If <trim_spec> is omitted, then BOTH is implied. If char is omitted, then a space character is implied as listed in Table 3-14.
Table 3-14 Arguments Used with the TRIM Function
| Argument | Description |
|---|---|
|
<trim_spec> |
a specification: |
|
char |
a single character |
|
string |
the target string to be trimmed |
Purpose
Removes leading and/or trailing blanks (or other characters) from a string.
Example
SELECT TRIM ('OLD' FROM 'OLDMAN') FROM DUAL;
Returns the following result.
TRIM('
------
MAN
Syntax with Numeric Arguments
TRUNC(n [, m])
Syntax with Date Arguments
TRUNC(d [, fmt])
Purpose with Numeric Arguments
Returns n truncated to m decimal places, where m and n are numeric arguments. If m is omitted, truncates to 0 places. If m is negative, truncates (makes zero) m digits to the left of the decimal point.
Purpose with Date Arguments
Returns the date d with its time portion truncated to the time unit specified by the format model fmt. If you omit fmt, then d is truncated to the nearest day.
Usage Notes
The format models to be used with the TRUNC (and ROUND) date function, and the units to which it rounds dates are listed in Table 3-15. The default model, DD, returns the date rounded to the day with a time of midnight.
Table 3-15 Arguments Used with the TRUNC Function
| Format Model | Rounding Unit |
|---|---|
|
|
Century |
|
|
Year (rounds up on July 1) |
|
|
ISO Year |
|
|
Quarter (rounds up in the sixteenth day of the second month of the quarter) |
|
|
Month (rounds up on the sixteenth day) |
|
|
Same day of the week as the first day of the year |
|
|
Same day of the week as the first day of the ISO year |
|
|
Same day of the week as the first day of the month |
|
|
Day |
|
|
Starting day of the week |
|
|
Hour |
|
|
Minute |
Example 1
SELECT TRUNC(TO_DATE('27-OCT-92', 'DD-MON-YY'), 'YEAR') "First Of The Year"
FROM DUAL;
Returns the following result.
First Of T ---------- 1992-01-01
Example 2
SELECT TRUNC(15.79,1) "Truncate" FROM DUAL;
Returns the following result.
Truncate
---------
15.7
Example 3
SELECT TRUNC(15.79,-1) "Truncate" FROM DUAL;
Returns the following result.
Truncate
---------
10
Syntax
UPPER(char)
Purpose
Returns the string argument char with all its letters converted to uppercase. The return value has the same datatype as char.
Example
SELECT UPPER('Carol') FROM DUAL;
Returns the following result.
UPPER ----- CAROL
ODBC Function
{fn UCASE (char)}
Syntax
USER
Purpose
Returns the current schema name as a character string.
Example 1
SELECT USER "User" FROM DUAL;
Returns the following result.
User -------- SYSTEM
Example 2
SELECT {fn USER()} FROM DUAL;
Returns the following result.
{FNUSER()}
------------------------------
SYSTEM
ODBC Function
{ fn USER()}
Syntax
VARIANCE([DISTINCT|ALL] x)
Purpose
Returns variance of x, a number. Oracle Lite calculates the variance of x using this formula.
xi is one of the elements of x.
n is the number of elements in the set x. If n is 1, the variance is defined to be 0.
Example
SELECT VARIANCE(sal) "Variance" FROM emp;
Returns the following result.
Variance --------- 1398313.9
Syntax
{ fn WEEK ( <value_expression> ) }
Purpose
Returns the week of the year as an integer using arguments listed in Table 3-16.
Table 3-16 Arguments Used with the WEEK Function
| Argument | Description |
|---|---|
|
<value_expression> |
A date on which the week is computed. The result is between 1 and 53. |
Example 1
SELECT {fn WEEK({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNWEEK({FNCURDATE()})}
-----------------------
16
Example2
SELECT {fn week('1999-06-15')} FROM DUAL;
Returns the following.
EK('1999-06-15')}
-----------------
25
Syntax
YEAR (date_exp)
Purpose
Returns the YEAR as an integer.
Example 1
SELECT {FN YEAR ('06-15-1966')} FROM DUAL;
Returns the following result.
{FNYEAR('06-15-1966')}
----------------------
1966
Example 2
SELECT {fn YEAR({fn CURDATE()})} FROM DUAL;
Returns the following result.
{FNYEAR({FNCURDATE()})}
-----------------------
1999
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