Tag archive
Commands grouped around the same concept, pattern, or recurring problem.
Remove matching rows with `DELETE`, then query the remaining table contents.
Remove rows from one table when a matching row exists in another table using a subquery.
Remove rows from one table based on matching rows in another table.
Use `BEGIN`, `COMMIT`, and `ROLLBACK` to execute multiple statements as an atomic unit.
Add new data to a table, then verify the inserted row with a deterministic query.
Add several rows in one statement using a multi-value `INSERT`.
Atomically insert a row if it does not exist or update it if it does, using the database's native conflict-resolution syntax.
Insert rows without raising an error when a unique constraint is violated, using each engine's conflict-ignore syntax.
Populate a table by selecting rows from another table using `INSERT INTO ... SELECT`.
Mark a named checkpoint inside an open transaction so you can roll back to that point without aborting the whole transaction.
Use `MERGE` to insert new rows, update matching ones, and delete rows that should be removed — all in a single statement against a source table.
Set a column to different values depending on other column values in the same row by using `CASE WHEN` inside a `SET` clause.
Modify existing rows with `UPDATE`, then verify the changed data with a stable query.
Use a subquery in the `WHERE` clause of an `UPDATE` to restrict which rows are modified based on data from another table.
Use a join inside an `UPDATE` statement to copy or derive values from a related table.