Datatypes:
------------------------------------------------------------------------------------------------------------------1. Built-In Data Type:
Data type represents the type of data into a column based on data type, oracle engine allocates required memory for each value and the column.
A. String datatypes:
CHAR(size): to store fixed length char value.
by default size is 1 char and Max size is 2000 char.
VARCHAR2(size): to store variable length char values & no minimum size, in this case, we must specify size.
Max size is 4000 char(upto 11g)
Max size is 32000 char(from 12c)
NCHAR(size): to store fixed length unicode character
NCHAR2(size): to store variable length unicode character.
LONG: it is similar to varchar2 datatype but max size is 2GB.
2. Numerical Data Type:
TO store Number type Data.
Number(precesion): it will store numeric values without decimal point. precesion represent Max no of digit in the value.
Max value of precesion is 38 digits.
Number(precesion, scale): to store values with decimal point, scale represents max no of digits after decimal point.
EX: emp number(5)
prod_price(7,2)
3. Date Data Type:
Date: To store date type data.
Oracle system defined date format as
DD-MON-YY
DD- Date Digits
MON- First three char of month
YY - last 2 digits of year
Current_TimeStamp: to store date value, along with time format.
DD-MON-YY HH:MM:SS AM/PM
4. Binary Data Types:
Binary data type means unstructured data like images, digital signatures, thumb impressions, audio & video files.
RAW(size): max size 2000 bytes.
LONGRAW(size): max size 2GB.
5. LOB Data Types: (Large Objects)
to store large objects having more size then 2GB & max size is 4 GB.
CLOB: char LOB
BLOB: binary LOB
NCLOB: multi character LOB
6. ROWID: maintain physical address of each record.
7. Bfile: It is a pointer to a Binary File.
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--> Type Casting in JAVA
--> Data Type in JAVA
