Results for “Postgres”
Small, practical examples. Search by task or narrow things down below.
Accept either of two conditions
Postgres: Use OR to keep matching names or out-of-stock rows.
Postgres✓ Tested
Add an optional field to an existing table
Postgres: A nullable column permits existing rows to remain valid while data is filled later.
Postgres✓ Tested
Add values across several rows
Postgres: Use SUM to calculate a total quantity.
Postgres✓ Tested
Apply a default when an insert omits a column
Postgres: A default supplies an omitted value; an explicit NULL still follows the column’s nullability rules.
Postgres✓ Tested
Attach an overall count to every row
Postgres: An uncorrelated scalar subquery supplies the same aggregate to each output row.
Postgres✓ Tested
Block deletion of a referenced parent
Postgres: The default foreign-key action prevents deletion while a child still refers to the parent.
Postgres✓ Tested
Build a query from several named stages
Postgres: Separate row selection from aggregation using two common table expressions.
Postgres✓ Tested
Calculate a cumulative integer percentage
Postgres: Divide a running window sum by the complete total using a unique ordering key.
Postgres✓ Tested
Calculate a total for each group
Postgres: Group nonmissing categories and calculate separate totals.
Postgres✓ Tested
Calculate a value with SELECT
Postgres: Evaluate a small arithmetic expression on the database server.
Postgres✓ Tested
Calculate each group’s integer percentage of the total
Postgres: Multiply before division and protect against a zero denominator.
Postgres✓ Tested
Calculate each group’s numeric spread
Postgres: Subtract MIN from MAX to report the difference between extremes.
Postgres✓ Tested