Retrieving data.
WHAT YOU CAN DO
Filter, sort, limit, group and aggregate, without writing queries.
WHAT TO PREFER
Retrieving only the columns you need Retrieving only the rows you need
WHY
Loading whole tables into memory is a common cause of failure.
WHAT TO USE FOR LARGE RESULTS
Processing in chunks, rather than loading everything.
WHAT RETURNS WHAT
A single record, or nothing A collection, possibly empty
WHAT TO HANDLE
The case where nothing is found.
WHAT TO USE WHEN ABSENCE IS AN ERROR
The variant that fails, producing a not-found response automatically.
WHAT TO BE CAREFUL WITH
Queries inside loops Conditions built from input without validation
WHAT PARAMETERISATION HAPPENS AUTOMATICALLY
Values in standard query methods.
WHAT DOES NOT
Raw expressions, and dynamic column names.
WHAT TO DO ABOUT THOSE
Bind values explicitly, and validate column names against a permitted list.
WHAT TO INSPECT WHEN SOMETHING IS SLOW
The generated queries and their count.
