Tag archive
Commands grouped around the same concept, pattern, or recurring problem.
Audit a table for `NULL` values by counting how many rows have no value in each column of interest.
Group rows by the candidate key and keep only values that appear more than once.
Find child rows whose foreign key value does not match any row in the parent table.
Use a `WHERE` predicate to list rows that already break a business or constraint rule.
Schema and metadata choices tend to survive longer than any one statement, which is why naming and structure deserve more care than a temporary query draft.