SQL · Theory

Today

← All stacks

Theory

310/439

Today

Today sits in a viva board. Dev’s job is Today on Dev's board. Write that first.

Today on the board — one Today step Dev can write from memory. Then say what Today on Dev's board looks like after.

Without Today, a viva board gets messy and Today on Dev's board is hard to trust.

Use Today when Today on Dev's board must stay clear. If a simpler SQL step works, use that instead.

Today miss — copy-pasting Today without a dry-run. Fix it before you talk about advanced SQL.

Place Today next to nearby SQL work — one Today step Dev can write from memory is the link.

Close Today with — “If I skip it, Today on Dev's board goes wrong like this: copy-pasting Today without a dry-run.”

Exam tip

Say Today in one breath, then one Today step Dev can write from memory, then copy-pasting Today without a dry-run.

Today — sample query

-- Today
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;

Today: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefToday — Dev uses it for Today on Dev's board in a viva board.
RuleToday → one Today step Dev can write from memory.
RememberToday + InnoDB (a viva board).
UseToday in a viva board (Today on Dev's board).
TrapToday — copy-pasting Today without a dry-run.
ExToday → Today on Dev's board.

-- Today 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;

Today

Today — sample query

Short notes

Questions

Today

Today — sample query

Short notes

Questions