DataType

Data type is used to specify the type of data that will be stored in a particular memory location.

Types of Data Type

1. CHAR

2. VARCHAR/ VARCHAR2

3. NUMBER

4. DATE

5. LARGE OBJECT

   1. CHARACTER LARGE OBJECT

   2. BINARY LARGE OBJECT

CHAR

1. CHAR datatype can accept ‘A - Z’, ‘a - z’, ‘0 - 9’, ‘special characters’ as well as ‘ Alphanumerics’.

2. Characters must always be enclosed within single quotes

   Syntax: CHAR (SIZE)

3. Whenever we use CHAR datatype we must mention it’s size.

SIZE

1. It is used to specify number of characters it can store

2. The maximum no. of characters it can store is 2000 characters.

3. CHAR datatype follows fixed length memory allocation.

VARCHAR

1. VARCHAR datatype can accept ‘A - Z’, ‘a - z’, ‘0 - 9’, ‘special characters’ as well as ‘ Alphanumerics’.

2. Characters must always be enclosed within single quotes

   Syntax: VARCHAR (SIZE)

3. Whenever we use VARCHAR datatype we must mention it’s size.

SIZE

1. It is used to specify number of characters it can store

2. The maximum no. of characters it can store is 2000 characters.

3. CHAR datatype follows variable length memory allocation.

VARCHAR2

1. It is an updated version of VARCHAR2 datatype

2. It can store up to 4000 characters

Syntax: VARCHAR (SIZE)

DATE

1. It is used to store the date in a particular format.

2. It use ORACLE specified format

   1. ‘DD-MON-YYYY’

   2. ‘DD-MON-YY’

Syntax: DATE

3. e.g. ‘28-AUG-2024’, ‘28-AUG-24’

NUMBER

1. It is used to store the numeric value

   Syntax: NUMBER(PRECISION, [SCALE])

2. PRECISION:

   It is used to specify the number of digits to store the integer values

3. SCALE:

   It is used to specify the number of digits to store decimal values within the precision

   The default value of scale is 0

   SCALE is optional

LARGE OBJECT

1. CHARACTER LARGE OBJECT:

   It is used to store characters upto 4GB of size

2. BINARY LARGE OBJECT:

   It is used to store binary values of images, documents, etc, upto $GB of size.