PostgreSQL Insert Record: Insert rows from one table to another table

6. Write a SQL statement insert rows from the country_new table to countries table.

Here are the rows for country_new table. Assume that, the countries table is empty.

 country_id | country_name | region_id
------------+--------------+-----------
 C1         | India        |      1002
 C2         | USA          |
 C3         | UK           |
 C4         | India        |      1001
 C5         | USA          |      1007
 C6         | UK           |      1003
(6 rows)

Sample Solution:

Code:

-- This SQL statement inserts data into the 'countries' table by selecting all rows from the 'country_new' table.

INSERT INTO countries
SELECT * FROM country_new;

Explanation:

• The INSERT INTO ... SELECT statement allows inserting data into a table by selecting rows from another table or query result.
• In this case, countries is the destination table where the data will be inserted.
• SELECT * FROM country_new retrieves all columns and rows from the 'country_new' table.
• This statement effectively copies all data from the 'country_new' table and inserts it into the 'countries' table.

Here is the command to see the list of inserting rows :

postgres=# SELECT * FROM countries;


 country_id | country_name | region_id
------------+--------------+-----------
 C1         | India        |      1002
 C2         | USA          |
 C3         | UK           |
 C4         | India        |      1001
 C5         | USA          |      1007
 C6         | UK           |      1003
(6 rows)

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