非エンジニア向けSQLの基礎 ref: https://qiita.com/mrdShinse/items/447d1d5ad319b0f944da

file0.sql

SELECT companies.* FROM companies;

file1.sql

SELECT
  c.name,
  c.created_at
FROM companies AS c;

file2.sql

SELECT *
FROM users AS u
WHERE u.company_id = 2
  AND u.email IS NULL;

file3.sql

SELECT u.name,
       u.created_at
FROM users AS u
WHERE u.company_id IN (1, 2)
  AND u.created_at > '2017-12-08 11:11:45'

file4.sql

SELECT *
FROM users AS u
WHERE u.name LIKE '田中%'