SQL · Theory

localtimestamp()

Theory

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localtimestamp()

localtimestamp() is simple if you keep it on paper. Meera uses it for Meera walking through localtimestamp in lab hour.

localtimestamp() on the board: one localtimestamp step Meera can write from memory. Then say what Meera walking through localtimestamp looks like after.

Skip localtimestamp() and skipping the failure case for localtimestamp shows up in lab hour.

Meera ships localtimestamp() in lab hour. That is the use case worth saying.

If Meera walking through localtimestamp breaks under localtimestamp(), check skipping the failure case for localtimestamp first.

After localtimestamp(), Meera should still remember skipping the failure case for localtimestamp.

Close localtimestamp() with: “If I skip it, Meera walking through localtimestamp goes wrong like this: skipping the failure case for localtimestamp.”

Exam tip

For localtimestamp(): definition + lab hour + one failure.

localtimestamp() — sample query

-- localtimestamp()
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;

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

Short notes

Deflocaltimestamp() — Meera uses it for Meera walking through localtimestamp in lab hour.
Rulelocaltimestamp() → one localtimestamp step Meera can write from memory.
Rememberlocaltimestamp() + the query planner (lab hour).
Uselocaltimestamp() in lab hour (Meera walking through localtimestamp).
Traplocaltimestamp() — skipping the failure case for localtimestamp.
Exlocaltimestamp() → Meera walking through localtimestamp.

-- localtimestamp() 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;

localtimestamp()

localtimestamp() — sample query

Short notes

Questions

localtimestamp()

localtimestamp() — sample query

Short notes

Questions