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Replace

Replace is a SQL idea you prove with a Replace dry-run, not with a slogan.

For Replace, the query planner is in play. Don’t blame it until you have traced a Replace dry-run.

Replace exists so Dev can keep a Replace dry-run correct in a campus project.

Replace shows up in a campus project. Name a Replace dry-run, not “a real-world scenario”.

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

Replace is not a lonely heading. Dev ties it to a Replace dry-run.

Close Replace with — “If I skip it, a Replace dry-run goes wrong like this: only reciting the name of Replace.”

Exam tip

For Replace: definition + a campus project + one failure.

Replace — sample query

-- Replace
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;

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

Short notes

DefReplace — Dev uses it for a Replace dry-run in a campus project.
RuleReplace → one Replace step Dev can write from memory.
RememberReplace + the query planner (a campus project).
UseReplace in a campus project (a Replace dry-run).
TrapReplace — only reciting the name of Replace.
ExReplace → a Replace dry-run.

-- Replace 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;

Replace

Replace — sample query

Short notes

Questions

Replace

Replace — sample query

Short notes

Questions