Your path

Step 1
Where SQL enters the testing cycle~0.8 h · Orientation
Step 2 · by the author’s design, after “Where SQL enters the testing cycle”inside a rung the order is up to you
Reading a schema you did not design~1 h · Orientation
Staying safe on a shared test environment~1 h · Orientation
Optional: client data, PII and AI assistants~0.7 h · Optional
Step 3
A SELECT that answers exactly one question~0.9 h · Precise retrieval · by the author’s design, after “Reading a schema you did not design”
Step 4 · Precise retrieval
NULL and the logic that has three answers~1.1 h · by the author’s design, after “A SELECT that answers exactly one question”
Types, conversions and collation~1 h · by the author’s design, after any one of these: “Reading a schema you did not design”, “A SELECT that answers exactly one question”
Step 5
Dates, times and the last day of the month~1.1 h · Precise retrieval · by the author’s design, after any one of these: “A SELECT that answers exactly one question”, “Types, conversions and collation”
INNER and LEFT: which rows the join throws away~1 h · Across tables · by the author’s design, after any one of these: “A SELECT that answers exactly one question”, “NULL and the logic that has three answers”
Step 6
Orphans and links that point at nothing~1 h · Across tables · by the author’s design, after “INNER and LEFT: which rows the join throws away”
When a join multiplies your rows~1.1 h · Across tables · by the author’s design, after “INNER and LEFT: which rows the join throws away”
Set operations as reconciliation~1 h · Across tables · by the author’s design, after any one of these: “NULL and the logic that has three answers”, “INNER and LEFT: which rows the join throws away”
Optional: slow queries and blocked environments~0.8 h · Optional · by the author’s design, after any one of these: “Staying safe on a shared test environment”, “Dates, times and the last day of the month”
Step 7
GROUP BY and recomputing the report~1 h · Aggregation · by the author’s design, after any one of these: “A SELECT that answers exactly one question”, “When a join multiplies your rows”
Test data: setup and idempotent teardown~1.1 h · Data before and after the test · by the author’s design, after any one of these: “Staying safe on a shared test environment”, “Set operations as reconciliation”
Step 8
HAVING and finding duplicates~1 h · Aggregation · by the author’s design, after “GROUP BY and recomputing the report”
Subqueries and CTEs~1 h · Aggregation · by the author’s design, after any one of these: “When a join multiplies your rows”, “GROUP BY and recomputing the report”
Optional: why the schema looks like that~0.7 h · Optional · by the author’s design, after any one of these: “Reading a schema you did not design”, “GROUP BY and recomputing the report”
Step 9
Window functions for the tester~1.1 h · Aggregation · by the author’s design, after any one of these: “HAVING and finding duplicates”, “Subqueries and CTEs”
Optional: end-to-end migration reconciliation~1 h · Optional · by the author’s design, after 2 of these: “Orphans and links that point at nothing”, “Set operations as reconciliation”, “HAVING and finding duplicates”
Step 10
Verifying what the application actually wrote~1.1 h · Data before and after the test · by the author’s design, after any one of these: “Window functions for the tester”, “Test data: setup and idempotent teardown”
Step 11 · Data before and after the test · by the author’s design, after any one of these: “Test data: setup and idempotent teardown”, “Verifying what the application actually wrote”
Reading views, procedures and triggers~1 h
Turning a check into a deterministic assertion~1.1 h
Step 12
Optional: build ENGAGE locally and run the checks~1.5 h · Optional · by the author’s design, after any one of these: “Reading a schema you did not design”, “Turning a check into a deterministic assertion”
Examfinal · in the browser, without the assistantclosed · enrol on the course

0 of 24 units done · ~19.4 h without the optional units, ~24.1 h with them

Dates, times and the last day of the month

This unit is open to those enrolled

Enrolment is free — it is what lets the server remember your progress between sessions.