Results for “Postgres”
Small, practical examples. Search by task or narrow things down below.
Report duplicate business values and their frequency
Postgres: Group by a candidate business key and retain only groups with multiple rows.
Postgres✓ Tested
Require a value with NOT NULL
Postgres: Declare required fields at the database boundary, not only in application validation.
Postgres✓ Tested
Require two filtering conditions
Postgres: Combine category and quantity conditions with AND.
Postgres✓ Tested
Return all rows tied for the maximum in a group
Postgres: An equality comparison with a grouped maximum retains ties rather than choosing one arbitrary row.
Postgres✓ 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
Run a first SELECT query
Postgres: Return a literal value without creating a table.
Postgres✓ Tested
Search for a literal LIKE wildcard
Postgres: Declare an escape character so a percent sign in the pattern is literal.
Postgres✓ Tested
Select the top row in each group with a tie-breaker
Postgres: Filter an outer query on ROW_NUMBER because window functions are not evaluated in WHERE.
Postgres✓ Tested
Select values in an inclusive range
Postgres: BETWEEN includes both endpoints of the range.
Postgres✓ Tested
Show a group total beside each detail row
Postgres: A partitioned aggregate preserves detail rows instead of collapsing them with GROUP BY.
Postgres✓ Tested
Sort preferred rows ahead of other rows
Postgres: A CASE ordering key expresses business priority before a stable secondary sort.
Postgres✓ Tested
Sort the highest quantities first
Postgres: Specify descending order and a stable tie breaker.
Postgres✓ Tested