Results for “persistent data”
Small, practical examples. Search by task or narrow things down below.
Return all rows tied for the maximum in a group
SQLite: An equality comparison with a grouped maximum retains ties rather than choosing one arbitrary row.
SQLite✓ Tested
Return an inserted row
Read generated data directly from INSERT.
RETURNING✓ Tested
Return zero for a sum over no rows
SQL: SUM produces NULL for an empty input; COALESCE supplies the desired reporting default.
SQL✓ Tested
Return zero for a sum over no rows
SQL Server: SUM produces NULL for an empty input; COALESCE supplies the desired reporting default.
SQL Server✓ Tested
Return zero for a sum over no rows
Postgres: SUM produces NULL for an empty input; COALESCE supplies the desired reporting default.
Postgres✓ Tested
Return zero for a sum over no rows
SQLite: SUM produces NULL for an empty input; COALESCE supplies the desired reporting default.
SQLite✓ Tested
Roll back a trial update
Group a change in a transaction and undo it.
transaction✓ Tested
Round a timestamp down to its month
Group dates by a calendar boundary.
date_trunc✓ Tested
Run a first SELECT query
SQL: Return a literal value without creating a table.
SQL✓ Tested
Run a first SELECT query
SQL Server: Return a literal value without creating a table.
SQL Server✓ Tested
Safely read a caught error
Check the error type before accessing its message.
unknown✓ Tested
Save and reload an image archive
Docker / Compose: save preserves image metadata and tags for later loading.
Docker / Compose✓ Tested