SQL
Overview
Databases
Tasks
Drop database:
DROP database db_name;
Alter tables:
ALTER TABLE table_name
ADD COLUMN new_column_name data_type;
ALTER TABLE table_name
RENAME old_column_name TO new_column_name;
Create:
INSERT INTO "users" (last_name, first_name)
VALUES ('Alice', ''), ('Bob', '');
Read:
SELECT *
FROM users
WHERE id = 1;
Update:
UPDATE users
SET telegram_name = 'idealhack'
WHERE telegram_id = 34804908;
Delete:
DELETE FROM torrents
WHERE id = 166;
IN operator:
DELETE FROM torrents WHERE id NOT IN ( SELECT torrent_id FROM user_torrents );
JOIN operator:
SELECT a.name, b.id, b.name
FROM db_a.tb_a as a JOIN db_b.tb_b as b
WHERE a.name = "test" AND a.b_id = b.id;