oracle sql built-in functions chapter 5 in lab reference
TRANSCRIPT
Oracle SQL Oracle SQL
Built-in FunctionsBuilt-in Functions
Chapter 5 in Lab Reference
Column Alias Names
Example:Example:
Select name AS Employee
From employee;
Built-in Functions 2
EMPLOYEE-------------------------------
Jamil N.Samir Amani F.Zaki Jihan H.Walid Ramy S.Nabil Joyce A.Eman Ahmad V.Jabbar James B.Baher
7 rows selected.
Column Alias Names
When you want to include spaces or special characters in alias names, then enclose the alias name in double quotation marks.
Example:Example:
Select name || ' has an id of ' || ssn "Important information"
From employee;
Built-in Functions 3
IMPORTANT INFORMATION---------------------------------------------------------------------------------
Jamil N.Samir has an id of 123456789Amani F.Zaki has an id of 999887777Jihan H.Walid has an id of 987654321Ahmad V.Jabbar has an id of 987987987James B.Baher has an id of 888665555
7 rows selected.
Table Alias Names
Example:Example:
Select T.item_id, T.item_desc
From item T;
Built-in Functions 4
ITEM_ID ITEM_DESC --------------------------------------------------------- LA-101 Box, Small
NY-102 Bottle, Large
Number FunctionsROUND
The ROUND function rounds the value you want to modify.
Example:Example:
Select product_name, product_price, ROUND(product_price,0) From product;
Built-in Functions 5
PRODUCT_NAME PRODUCT_PRICE ROUND(PRODUCT_PRICE,0)----------------------------------------------------------------------------------------------------------------------------------------------
Roco Pencil 3.95 4
FABER Pen 5 5
Roco Pad 2.2 2
Number FunctionsTRUNC
The TRUNC function truncates precision from a number.
Example:Example:
Select product_name, product_price, TRUNC(product_price,0) From product;
Built-in Functions 6
PRODUCT_NAME PRODUCT_PRICE TRUNC(PRODUCT_PRICE,0)--------------------------------------------------------------------------------------------------------------------------------------------
Roco Pencil 3.95 3
FABER Pen 5 5
Roco Pad 2.2 2
Number FunctionsMOD
mod(m,n)
Example:Example:
Select mod(salary,3)
From employee
where ssn=123456789;
Built-in Functions 7
MOD(SALARY,3)-------------------------------------
0
Number FunctionsPOWER
power(m,n)
number m raised to the power of n.
Example:Example:
Select power(salary,2)
From employee
where ssn=123456789;
Built-in Functions 8
POWER(SALARY,2)-------------------------------------------
900000000
Number FunctionsSIGN & SQRT
sign(n) if n=0 returns 0 if n>0 returns 1 if n<0 returns -1
sqrt(n) returns square root of n.
Example:Example:
Select sqrt(salary)
From employee
where ssn=123456789;
Built-in Functions 9
SQRT(SALARY)--------------------------------------
173.20508
Text FunctionsUPPER, LOWER & INITCAP
These three functions change the case of the text you give them.
Example:Example:
Select UPPER(product_name)
From product;
Example:Example:
Select LOWER(product_name)
From product;
Built-in Functions 10
UPPER(PRODUCT_NAME) --------------------------------------------------------
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FABER PEN ROCO PAD
LOWER(PRODUCT_NAME) --------------------------------------------------------
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Example:Example:
Select INITCAP(product_name)
From product;
Built-in Functions 11
Text FunctionsUPPER, LOWER & INITCAP
INITCAP(PRODUCT_NAME)----------------------------------------------------------
Roco Pencil
Faber Pen Roco Pad
To determine the lengths of the data stored in a database column.
Example:Example:
Select product_name, LENGTH(product_name) AS Name_Length
From Product
where LENGTH(product_name)>8;
Built-in Functions 12
Text FunctionsLENGTH
PRODUCT_NAME NAME_LENGTH ---------------------------------------------------------------------------------
FABER Pen 9
Roco Pencil 11
Text FunctionsSUBSTR
To separate multiple bits of data into discrete segments.
Example:Example:
Select SUBSTR(item_id,1,2) Location, SUBSTR(item_id,4,3) Number, Item_desc
From item;
Built-in Functions 13
LOCATION NUMBER ITEM_DESC---------------------------------------------------------------------------------------------
LA 101 Box, Small NY 102 Bottle, Large
Text FunctionsINSTR
Useful when you have substrings vary in length. This mean not only is the length of the first substring is unknown, but the starting position of the second substring can also vary.
Example:Example:
Select item_desc, INSTR(item_desc, ’,’ , 1)
From item;
Built-in Functions 14
ITEM_DESC INSTR(ITEM_DESC, ’,’ , 1)
--------------------------------------------------------------------------------------------
Box, Small 4 Bottle, Large 7
Text FunctionsREPLACE
Replace(char, str1, str2)
Every occurrence of str1 in char is replaced by str2.
Example:Example:
Select Replace(name,'Jamil','Sara')
From employee;
Built-in Functions 15
REPLACE(NAME,'JAMIL','SARA')-------------------------------------------------------------------
Sara N.Samir Amani F.Zaki Jihan H.Walid Ramy S.Nabil Joyce A.Eman Ahmad V.Jabbar James B.Baher
7 rows selected.
Text Functions Concatenation operator ||
To concatenate column names with other column names or with literal characters.
Example:Example:
Select name || ‘ has an id of ‘ || ssn
From employee;
Built-in Functions 16
NAME||’HAS AN ID OF'||SSN------------------------------------------------------------------------------
Jamil N.Samir has an id of 123456789 Amani F.Zaki has an id of 999887777 Jihan H.Walid has an id of 987654321 Ramy S.Nabil has an id of 666884444 Joyce A.Eman has an id of 453453453 Ahmad V.Jabbar has an id of 987987987 James B.Baher has an id of 888665555
7 rows selected.
Date Functions
FunctionDescriptionSyntax
SysdateGet current system date and time.
INSERT INTO employee VALUES(…………, trunc(sysdate),……….);
Add_months(d, n)Adds n months to date d.
ADD_MONTHS(starting_date, number_of_months)
Months_between(f, s)Difference in months between date f and date s.
MONTHS_BETWEEN(later_date, earlier_date)
Built-in Functions 17
Data Conversion Functions
Built-in Functions 18
FunctionDescription
To_char(input_value, format_code)Converts any data type to character data type.
To_number(input_value, format_code) Converts a valid set of numeric character data to number data type.
To_date(input_value, format_code)Converts character data of the proper format to date data type.
Null values
Some columns may contain Null values.
You can use the NVL function to display actual values instead of null values in a query result.
NVL(column|expression, replacement_value)
Replacement_value must be of the same data type of the column (if not use data conversion functions).
Built-in Functions 19
Null values
Example:Example:
Select name, NVL(SUPERSSN, ‘333445555‘)
From employee;
Built-in Functions 20
NAME NVL(SUPERSSN, ‘333445555’)-------------------------------------------------------------------------------------------------
Jamil N.Samir 333445555 Amani F.Zaki 987654321 Jihan H.Walid 888665555 Ramy S.Nabil 333445555 Joyce A.Eman 333445555 Ahmad V.Jabbar 987654321 James B.Baher 333445555
7 rows selected.