MySQL and MariaDB, which is a fork of MySQL are relational database management systems that share a common command syntax. For both, you can see available databases with the command
show
databases
.
MariaDB [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | ann | | crystal | | grover | | horticulture | | justiceleague | | maker | | mars | | moon | | orwell | +--------------------+ 10 rows in set (0.09 sec) MariaDB [(none)]>
You can see the tables within a particular database by selecing the database
with use dbname
, where dbname is the name of the
database, and then using show tables;
.
MariaDB [(none)]> use crystal Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [crystal]> show tables; +---------------------------+ | Tables_in_crystaltokyo | +---------------------------+ | smf_admin_info_files | | smf_approval_queue | | smf_attachments | | smf_ban_groups | | smf_ban_items | | smf_board_permissions | | smf_boards | | smf_buddies | | smf_calendar | | smf_calendar_holidays | | smf_categories | | smf_collapsed_categories | | smf_custom_fields | | smf_gallery_cat | | smf_gallery_comment | | smf_gallery_pic | | smf_gallery_report | | smf_group_moderators | | smf_hcb_reminders | | smf_links | | smf_links_bans | | smf_links_categories | | smf_links_comments | | smf_log_actions | | smf_log_activity | | smf_log_banned | | smf_log_boards | | smf_log_comments | | smf_log_digest | | smf_log_errors | | smf_log_floodcontrol | | smf_log_group_requests | | smf_log_httpBL | | smf_log_karma | | smf_log_mark_read | | smf_log_member_notices | | smf_log_notify | | smf_log_online | | smf_log_packages | | smf_log_polls | | smf_log_reported | | smf_log_reported_comments | | smf_log_scheduled_tasks | | smf_log_search_messages | | smf_log_search_results | | smf_log_search_subjects | | smf_log_search_topics | | smf_log_spider_hits | | smf_log_spider_stats | | smf_log_subscribed | | smf_log_topics | | smf_mail_queue | | smf_membergroups | | smf_members | | smf_message_icons | | smf_messages | | smf_moderators | | smf_openid_assoc | | smf_package_servers | | smf_permission_profiles | | smf_permissions | | smf_personal_messages | | smf_picture_comments | | smf_pm_recipients | | smf_pm_rules | | smf_poll_choices | | smf_polls | | smf_profile_albums | | smf_profile_comments | | smf_profile_pictures | | smf_scheduled_tasks | | smf_sessions | | smf_settings | | smf_smileys | | smf_spiders | | smf_subscriptions | | smf_tags | | smf_tags_log | | smf_themes | | smf_topics | +---------------------------+ 80 rows in set (0.00 sec) MariaDB [crystal]>
You can view details on the columns in a particular table by using
DESCRIBE tablename
where tablename
is the
name of the table.
MariaDB [crystal]> DESCRIBE smf_smileys; +--------------+----------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +--------------+----------------------+------+-----+---------+----------------+ | id_smiley | smallint(5) unsigned | NO | PRI | NULL | auto_increment | | code | varchar(30) | NO | | | | | filename | varchar(48) | NO | | | | | description | varchar(80) | NO | | | | | smiley_row | tinyint(4) unsigned | NO | | 0 | | | smiley_order | smallint(5) unsigned | NO | | 0 | | | hidden | tinyint(4) unsigned | NO | | 0 | | +--------------+----------------------+------+-----+---------+----------------+ 7 rows in set (0.05 sec) MariaDB [crystaltokyo]>
You can also use EXPLAIN tablename
, since EXPLAIN
and DESCRIBE
are synonyms, but the DESCRIBE keyword is
more often used to view information about a table's structure, whereas EXPLAIN
is more often used to obtain a query execution plan, i.e., an explanation of
how MySQL would execute a query.
References: