Lesson Agenda
•Single-row SQL functions
•Character functions
•Number functions
•Working with dates
•Date Functions
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Oracle Database 11g: SQL Fundamentals I 3 - 15
Number Functions
•ROUND: Rounds value to a specified decimal
•TRUNC: Truncates value to a specified decimal
•MOD: Returns remainder of division
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Result |
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ROUND(45.926, |
2) |
45.93 |
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TRUNC(45.926, |
2) |
45.92 |
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MOD(1600, |
300) |
100 |
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Copyright © 2009, Oracle. All rights reserved. |
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Number Functions |
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Number functions accept numeric input and return numeric va u s. This section describes some of the number functions.
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Function |
Purpose |
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ROUND(column|expression, n) |
Rounds the column, expression, or value to n decimal |
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places or, if n is omitted, no decimal places (If n is |
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negative, numbers to the left of decimal point are rounded.) |
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TRUNC(column|expression, ) |
Truncat s the column, expression, or value to n decimal |
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places or, if n is omitted, n defaults to zero |
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MOD(m,n) |
Returns the remainder of m divided by n |
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Note: This list contains only some of the |
available number functions. |
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For more information, see the section on Numeric Functions in Oracle Database SQL Language Reference 11g, Release 1 (11.1).
Oracle Database 11g: SQL Fundamentals I 3 - 16
Using the ROUND Function
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SELECT ROUND(45.923,2), ROUND(45.923,0),
ROUND(45.923,-1) 
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FROM DUAL;
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DUAL is a dummy table that you can use to view results |
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from functions and calculations. |
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Using the ROUND Function |
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The ROUND function rounds the column, expression, or value to n d cimal places. If the second |
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argument is 0 or is missing, the value is rounded to zero de imal places. If the second argument is 2, the value is rounded to two decimal places. Conversely, if the second argument is –2, the value is rounded to two decimal places to the left (rounded to the nearest unit of 100).
The function can also be used with date functions.OnlyYou will see examples later in this lesson.
ROUND &
DUMMY, and one row with the value X. The DUAL table is useful when you want to return a value
only once (for example, he value of a constant, pseudocolumn, or expression that is not derived from a table with user data). The DUAL table is generally used for completeness of the SELECT clause
Internalowned by the user and can be accessed by all users. It contains one column,
SYSUse
syntax, because both SELECT and FROM clauses are mandatory, and several calculations do not need Oracleto select from the actual tables.
Oracle Database 11g: SQL Fundamentals I 3 - 17
Using the TRUNC Function
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SELECT TRUNC(45.923,2), TRUNC(45.923),
TRUNC(45.923,-1) 
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FROM DUAL;
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Academy The TRUNC function truncates the column, expression,Oracleor value to n decimal places.
The TRUNC function works with arguments similar to those of the ROUND function. If the second
argument is 0 or is missing, the value is truncated to ze o decimal places. If the second argument is 2, the value is truncated to two decimal places. Conversely, if the second argument is –2, the value is
truncated to two decimal places to the left. If the second argument is –1, the value is truncated to one |
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decimal place to the left. |
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Like the ROUND function, the TRUNC function can beOnlyused with date functions. |
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Oracle Database 11g: SQL Fundamentals I 3 - 18