Can I Create a Temporary Table from a SELECT Statement Without Explicit Column Definitions?

Temporary Tables without Explicit Column Declaration

Query:

Can a temporary (session-only) table be created solely from a SELECT statement, without relying on a separate CREATE TABLE statement and tedious column type specification?

Explanation:

Temporary tables are often useful for storing intermediate data during database operations. Creating them using a CREATE TABLE command requires manually specifying each column and its data type, which can be time-consuming.

Answer:

Yes, it is possible to create a temporary table directly from a SELECT statement using the following syntax:

CREATE TEMPORARY TABLE IF NOT EXISTS table2 AS (SELECT * FROM table1)

This command accomplishes the following:

• Temporary Table Creation: The CREATE TEMPORARY TABLE clause creates a temporary table named table2.
• Automatic Column Definition: The SELECT * statement selects all columns from the table1 table and automatiquement defines the columns and data types in the newly created temporary table, table2.
• Session-Only Visibility: As specified by the TEMPORARY keyword, the table will be visible only during the current session.
• Implicit Drop on Session Close: Upon the conclusion of the session, the temporary table will be automatically dropped, eliminating the need for explicit deletion.

This method saves time by avoiding the need to write separate CREATE TABLE and column definition statements, while still providing the benefits of temporary table usage.

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