Practice filters
The library starts with write-query practice and keeps direct links to the standard checker workspace.
Practice Library
Today plan
10 items3 review5 current2 transfer
The plan keeps the default balance near 50-60% current work, 25-35% review, and 10-20% transfer or stretch.
- due reviewRA-A01 - Write a two-column projection with exact aliases on an unfamiliar table
Due review keeps spacing transparent.
- due reviewRA-A02 - State source grain and requested result grain before writing SQL
Due review keeps spacing transparent.
- due reviewRA-A03 - Repair an unknown identifier using schema metadata rather than trial-and-error guessing
Due review keeps spacing transparent.
- current newM00-A01 - Guided run - execute a supplied query and identify status, row count, and columns
Current work advances the selected goal while keeping prerequisites visible.
- current newM01-A01 - Schema reasoning - match three tiny tables to row-grain statements
Current work advances the selected goal while keeping prerequisites visible.
- current newM02-A01 - Prediction - identify the complete column shape produced by SELECT star
Current work advances the selected goal while keeping prerequisites visible.
- current newM03-A01 - Prediction - choose the exact result header order for a three-column projection
Current work advances the selected goal while keeping prerequisites visible.
- current newM04-A01 - Prediction - calculate a simple expression for one visible row before running it
Current work advances the selected goal while keeping prerequisites visible.
- transfer debug stretchM00-A04 - First independent check - write a one-column query from a blank editor
Transfer, debugging, or stretch work checks flexible use of prior skills.
- transfer debug stretchM01-A04 - Relationship preview - identify the child foreign key and parent key
Transfer, debugging, or stretch work checks flexible use of prior skills.
Session can be adjusted before starting.
M00-A03 - Controlled edit - change one requested literal and explain changed rows
one row per Austin customer after the controlled literal edit
M00-A04 - First independent check - write a one-column query from a blank editor
one row per product name
M01-A03 - Uniqueness prediction - verify whether a candidate column identifies rows
one uniqueness decision for the candidate column
M01-A06 - Transfer checkpoint - identify grain, primary key, foreign key, and output grain
one checkpoint row describing the transfer schema grain and keys
M02-A03 - Edit - replace star with one named column and compare result shape
one customer_name value per customer row
M02-A04 - Write - retrieve one requested column from a second table
one status value per order row
M02-A06 - Scratch checkpoint - write a complete SELECT/FROM query from an exact output contract
one order_id value per order row
M03-A04 - Alias - rename a technical source column to a report-friendly output name
one aliased order number per order row
M03-A06 - Contract checkpoint - produce three columns with exact aliases and order on a transfer table
one commerce customer row with three exact report aliases
M04-A03 - Edit - add a discount calculation with explicit parentheses
one discounted price per product row
M04-A04 - Text expression - build a readable label from two known columns
one readable label per product row
M04-A06 - Scratch checkpoint - return two derived columns with exact aliases and numeric behavior
one row per order item with two derived numeric columns
M05-A02 - Write - filter an exact text value with correct literal syntax
one row per completed order
M05-A03 - Edit - change an exclusive threshold to an inclusive one
one row per product at or above the price boundary
M05-A04 - Date boundary - return rows before a specified date
one row per product with a restock date before the boundary
M05-A06 - Boundary checkpoint - implement a two-sided range with edge-case hidden rows
one row per product inside the half-open restock window
M06-A03 - Write - accept either of two alternatives with OR
one row per order whose status matches either alternative
M06-A05 - Negation - express a business exclusion without double-negation confusion
one row per order not excluded by the business rule
M06-A06 - Transfer checkpoint - satisfy grouped alternatives plus a required condition
one transfer customer row satisfying a required condition plus grouped alternatives
M07-A02 - Write - filter membership in three enumerated values
one row per product whose category is in the requested list
M07-A04 - Write - implement an inclusive numeric band
one product row inside the inclusive stock-count band
M07-A06 - Boundary checkpoint - pass lower, upper, and just-outside range rows
one product row inside the inclusive price boundary checkpoint
M08-A02 - Write - find a substring with percent wildcards on both sides
one customer row whose name contains the requested substring
M08-A03 - Single-character task - use underscore for exactly one character
one product row matching the exact one-character pattern