Results for “base”
Small, practical examples. Search by task or narrow things down below.
Keep parent rows while filtering joined children
SQLite: Put a child filter in ON when unmatched parents must remain in the result.
SQLite✓ Tested
Keep rows matching a condition
SQL: Use WHERE to select rows with a particular category.
SQL✓ Tested
Keep rows matching a condition
SQL Server: Use WHERE to select rows with a particular category.
SQL Server✓ Tested
Keep unmatched rows with LEFT JOIN
Show every product even when stock is missing.
LEFT JOIN✓ Tested
Label rows with CASE
Derive a readable label from a condition.
CASE✓ Tested
List distinct values
Remove duplicate category values from a result.
DISTINCT✓ Tested
List unordered pairs without duplicate reversals
SQL: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
SQL✓ Tested
List unordered pairs without duplicate reversals
SQL Server: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
SQL Server✓ Tested
List unordered pairs without duplicate reversals
Postgres: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
Postgres✓ Tested
List unordered pairs without duplicate reversals
SQLite: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
SQLite✓ Tested
Make a pair of columns unique together
SQL: A composite primary key permits repeated individual values while forbidding a duplicate combination.
SQL✓ Tested
Make a pair of columns unique together
SQL Server: A composite primary key permits repeated individual values while forbidding a duplicate combination.
SQL Server✓ Tested