MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
USE db_name
The USE
statement tells MySQL to use the
db_name
db_name
database as the default
(current) database for subsequent statements. The database remains
the default until the end of the session or another
USE
statement is issued:
USE db1;
SELECT COUNT(*) FROM mytable; # selects from db1.mytable
USE db2;
SELECT COUNT(*) FROM mytable; # selects from db2.mytable
The database name must be specified on a single line. Newlines in database names are not supported.
Making a particular database the default by means of the
USE
statement does not preclude
accessing tables in other databases. The following example
accesses the author
table from the
db1
database and the editor
table from the db2
database:
USE db1;
SELECT author_name,editor_name FROM author,db2.editor
WHERE author.editor_id = db2.editor.editor_id;