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Show Trigger

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Theory

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Show Trigger

Meera only reaches for Show Trigger when Meera walking through Show Trigger has to stay correct in a campus project.

Keep Show Trigger small. Meera should finish Meera walking through Show Trigger in a few lines, not a 40-line dump.

Show Trigger exists so Meera can keep Meera walking through Show Trigger correct in a campus project.

Use Show Trigger when Meera walking through Show Trigger must stay clear. If a simpler SQL step works, use that instead.

Don’t do this with Show Trigger — only reciting the name of Show Trigger. Interviewers spot it in ten seconds.

After Show Trigger, Meera should still remember only reciting the name of Show Trigger.

One breath for Show Trigger, then Meera walking through Show Trigger, then only reciting the name of Show Trigger. Sit down.

Exam tip

For Show Trigger: definition + a campus project + one failure.

Show Trigger — sample query

-- Show 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;

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

Short notes

DefShow Trigger — Meera uses it for Meera walking through Show Trigger in a campus project.
RuleShow Trigger → one Show Trigger step Meera can write from memory.
RememberShow Trigger + InnoDB (a campus project).
UseShow Trigger in a campus project (Meera walking through Show Trigger).
TrapShow Trigger — only reciting the name of Show Trigger.
ExShow Trigger → Meera walking through Show Trigger.

-- Show 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;

Show Trigger

Show Trigger — sample query

Short notes

Questions

Show Trigger

Show Trigger — sample query

Short notes

Questions