Results for “SQL”
Small, practical examples. Search by task or narrow things down below.
Check whether text is valid JSON
Reject malformed input before processing it.
json_valid✓ Tested
Collect ordered values into an array
Build a sorted array from query rows.
array_agg✓ Tested
Combine matching rows with INNER JOIN
Read product names with their matching stock values.
INNER JOIN✓ Tested
Combine results while retaining duplicates
Postgres: UNION ALL does not spend work removing equal rows.
Postgres✓ Tested
Combine results without duplicates
Merge compatible result sets with UNION.
UNION✓ Tested
Combine text values with a separator
Postgres: Use the concatenation operator supported by the selected SQL dialect.
Postgres✓ Tested
Commit multiple related changes together
Postgres: The first transaction prepares the fixtures. The second commits both updates as one unit.
Postgres✓ Tested
Compare a row with its own group average
Postgres: A correlated aggregate computes a different comparison value for each group.
Postgres✓ Tested
Compare a row with the previous row
Read a preceding value with LAG.
LAG✓ Tested
Compare with a calculated value
Find products above the average price.
subquery✓ Tested
Compute a generated column
Store inputs and derive a value from them.
generated column✓ Tested
Compute an integer weighted average
Postgres: Multiply before summing and guard a zero total weight with NULLIF.
Postgres✓ Tested