Question

In an SQL query, which SQL keyword is used to specify the column names to be used in a join?

1) FROM
2) HAVING
3) JOIN
4) SELECT
5) WHERE

Answer 1

The keyword used to specify column names for use in an SQL join is SELECT. It determines which columns to return, while the JOIN keyword along with ON specifies the columns to join on.

Step-by-step explanation:

In an SQL query, the keyword used to specify the column names to be used in a join is SELECT. The SELECT keyword is used at the beginning of an SQL statement to determine which columns should be returned in the results. The actual join operation is performed using the JOIN keyword in conjunction with ON, where the specific columns on which the tables should be joined are specified.

For example, if we are joining two tables, TableA and TableB, on a common column 'id', the SQL query would look something like this:

SELECT TableA.*, TableB.*
FROM TableA
JOIN TableB
ON TableA.id = TableB.id;

This query returns all columns from both tables where the 'id' matches. It's worth noting that specifying column names using SELECT is independent of the tables being joined; you can also use aliases and functions on the columns within the SELECT statement.