← the tasting course

SQL

The soy sauce: sooner or later, everything gets dipped in it.

rice· fundamentals

the base everything rests on9 plates

What is SQL, actually?Databases, tables and your very first question, explained with a sushi restaurant.→

SELECT and WHERE: ordering from the menuHow to ask for exactly the columns and rows you want, nothing more.→

GROUP BY: counting what the kitchen soldAggregates squash rows into answers; GROUP BY decides how many answers you get.→

JOINs, explained at the counterWhat INNER and LEFT JOIN actually keep, shown with two tiny tables.→

ORDER BY and LIMIT: the bestseller listHow to rank your rows and keep only the top of the list.→

NULL: the empty plateWhat null really means, why = NULL never matches, and how IS NULL and COALESCE handle the plates that come back empty.→

INSERT, UPDATE, DELETE: writing in the notebookYour first writes: adding, changing and removing rows without wrecking the table.→

CREATE TABLE: designing the menuColumns, types and defaults: why the shape of a table decides how easy every later query will be.→

Keys: how tables hold handsPrimary keys, foreign keys, and the threads that let one table point at another.→

maki· advanced

rolling the pieces togetherin the kitchen

// in the kitchen

omakase· expert

chef level, no menu neededin the kitchen

// in the kitchen