Sql union

Problem

You’d like to display data from given columns (of a similar data type) from two tables in SQL.

Example

There are two tables in our database: and .

The table contains data in the following columns: , , , and .

id	first_name	last_name	age
1	Tom	Miller	22
2	John	Smith	26
3	Lisa	Williams	30
4	Charles	Davis	21
5	James	Moore	22

The table contains data in the following columns: , , , and .

id	first_name	last_name	age
1	Milan	Smith	45
2	Charles	Davis	21
3	Mark	Backer	19

In one result set, let’s display the first name, last name, and age for all people in the database, both employees and customers.

Solution 1

We’ll use to combine data from columns in two tables.

Here’s the query you’d write:

SELECT first_name, last_name, age FROM employee UNION ALL SELECT first_name, last_name, age FROM customer;

Here’s the result:

first_name	last_name	age
Tom	Miller	22
John	Smith	26
Lisa	Williams	30
Charles	Davis	21
James	Moore	28
Milan	Smith	45
Charles	Davis	21
Mark	Ba multiple select statements in sql stored procedure join multiple select statements in sql