SQL · Theory

Login with Different User

Theory

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Login with Different User

Login with Different User is about MySQL accounts, not table rows. Users are 'name'@'host'. CREATE USER, GRANT, ALTER USER … IDENTIFIED BY, DROP USER.

SHOW GRANTS FOR CURRENT_USER; to see yourself. Don’t use root from the app. Lock/unlock is ACCOUNT LOCK.

Trap — user@localhost vs user@% as two different accounts.

On the example next to this theory: Login with Different User: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Exam tip

'user'@'host', GRANT, not root from the app.

Login with Different User — sample query

-- Login with Different User
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Short notes

DefMySQL user = 'user'@'host' + password + grants.
RuleLeast privilege. App is not root.
Traplocalhost vs % accounts.

-- Login with Different User CREATE TABLE demo ( id INTEGER PRIMARY KEY, label TEXT NOT NULL, qty INTEGER DEFAULT 0 ); INSERT INTO demo (id, label, qty) VALUES (1, 'alpha', 2), (2, 'beta', 5); SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Login with Different User

Login with Different User — sample query

Short notes

Questions

Login with Different User

Login with Different User — sample query

Short notes

Questions