SQL · Theory

SPACE()()

Theory

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SPACE()()

SPACE()() (str) sits in a viva board. Dev’s job is a SPACE str dry-run. Write that first.

SPACE()() (str) on the board: one SPACE str step Dev can write from memory. Then say what a SPACE str dry-run looks like after.

Without SPACE()() (str), a viva board gets messy and a SPACE str dry-run is hard to trust.

Use SPACE()() (str) when a SPACE str dry-run must stay clear. If a simpler SQL step works, use that instead.

SPACE()() (str) miss — skipping the failure case for SPACE str. Fix it before you talk about advanced SQL.

Place SPACE()() (str) next to nearby SQL work — one SPACE str step Dev can write from memory is the link.

One breath for SPACE()() (str), then a SPACE str dry-run, then skipping the failure case for SPACE str. Sit down.

Exam tip

Board: a SPACE str dry-run. Dry-run SPACE()() (str). Name the trap: skipping the failure case for SPACE str.

SPACE()() — sample query

-- SPACE()()
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;

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

Short notes

DefSPACE()() (str) — Dev uses it for a SPACE str dry-run in a viva board.
RuleSPACE()() (str) → one SPACE str step Dev can write from memory.
RememberSPACE()() (str) + an index (a viva board).
UseSPACE()() (str) in a viva board (a SPACE str dry-run).
TrapSPACE()() (str) — skipping the failure case for SPACE str.
ExSPACE()() (str) → a SPACE str dry-run.

-- SPACE()() 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;

SPACE()()

SPACE()() — sample query

Short notes

Questions

SPACE()()

SPACE()() — sample query

Short notes

Questions