Column type: – A column type specifies type of data item. Column type is also known as data type. There are number of data types used in SQL for creating table structure with help of DDL. The datatype, specification of data type and description are as follows.

Data Type



Character Char(size) Character type data size is specified in number.
Varchar(size) Same as above.
Varchar2(size) Same as above and is recommended.
Date Date Used for specifying
Long Long Use for specifying long text up to 2 GB
Number Number Use to specify numeric data for single digit.
Number(size) Number with digit equal to specified size.
Number(size,dec) Same as above but dec indicates number of decimal size.
Decimal Same as number for single digit.
Float Same as number with two decimal point.
Integer Same as number but without decimal digit.
Smallint Same as integer.
Row Row(size) Row binary dat.
Long raw Long raw Raw large binary data.
Clob Clob Large binary and character data.
File Bfile File data.