Data Types in SQL

Data Types :


Datetime Data Types :

• The TIMESTAMP data type is an extension of the DATE data type.
• It stores the year, month, and day of the DATE data type plus hour, minute, and second values as well as the fractional second value.
• You can optionally specify the time zone.

• TIMESTAMP[(fractional_seconds_precision)]
• TIMESTAMP[(fractional_seconds_precision)] WITH TIME ZONE
  

DEFAULT Option in SQL

DEFAULT Option :

• Specify a default value for a column during an insert.
• ... hire_date DATE DEFAULT CURRENT_DATE, ...
• Literal values, expressions, or SQL functions are legal values.
• Another column’s name or a pseudo column are illegal values.
• The default data type must match the column data type.
• CREATE TABLE hire_dates (id numeric(8), hire_date DATE DEFAULT CURRENT_DATE);

Create the table :

• CREATE TABLE dept_info (deptno numeric(2), dname varchar(14), loc varchar(13), create_date DATE DEFAULT CURRENT_DATE);
  

Confirm table creation :

• \d dept_info