SQL · Theory

DROP Trigger

Theory

86/439

DROP Trigger

DROP Trigger is simple if you keep it on paper. Priya uses it for Priya walking through DROP Trigger in a campus project.

Do DROP Trigger once by hand. one DROP Trigger step Priya can write from memory. Change one input. Say the new result out loud.

Without DROP Trigger, a campus project gets messy and Priya walking through DROP Trigger is hard to trust.

DROP Trigger shows up in a campus project. Name Priya walking through DROP Trigger, not “a real-world scenario”.

DROP Trigger trap — only reciting the name of DROP Trigger. Priya loses marks for that every viva.

After DROP Trigger, Priya should still remember only reciting the name of DROP Trigger.

Viva for DROP Trigger: what it is → one DROP Trigger step Priya can write from memory → the mistake (only reciting the name of DROP Trigger).

Exam tip

Say DROP Trigger in one breath, then one DROP Trigger step Priya can write from memory, then only reciting the name of DROP Trigger.

DROP Trigger — sample query

-- DROP Trigger
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;

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

Short notes

DefDROP Trigger — Priya uses it for Priya walking through DROP Trigger in a campus project.
RuleDROP Trigger → one DROP Trigger step Priya can write from memory.
RememberDROP Trigger + an index (a campus project).
UseDROP Trigger in a campus project (Priya walking through DROP Trigger).
TrapDROP Trigger — only reciting the name of DROP Trigger.
ExDROP Trigger → Priya walking through DROP Trigger.

-- DROP Trigger 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;

DROP Trigger

DROP Trigger — sample query

Short notes

Questions

DROP Trigger

DROP Trigger — sample query

Short notes

Questions