How to insert values in table from another table

Points To Remember

• We can use subqueries in databases like Mysql and avoid multiple queries.
• Syntax - INSERT INTO table1 SELECT * FROM table2;
• We do not write VALUES in the query. 

Example : Insert Values from one table to another.

Suppose we have two table person and person_old with columns

• id int primary key
• name varchar
• age number
• contact varchar
• description text

And we want to copy all the details of the table person_old to table person. Then we must write our query as. This will insert all the rows of the person_old table to the new table person.

insert into person select * from person_old;

Also if we want to add only a few columns of the table person_old to the table person.Suppose we want to add only name, age and contact to the table person from table person_old where age is less than 25, then we can query as follows.

insert into person(name,age,contact) select name,age,contact from person_old  where age < 25;