Results for “SQL Server”
Small, practical examples. Search by task or narrow things down below.
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
Convert Unix time to a timestamp
Interpret a seconds-since-epoch value as UTC.
unixepoch✓ Tested
Copy selected rows into another table
Postgres: INSERT SELECT performs a set-based copy with an explicit destination column list.
Postgres✓ Tested
Count distinct values within a result
Postgres: COUNT DISTINCT counts distinct non-null values.
Postgres✓ Tested
Count rows per category
Aggregate rows sharing the same category.
GROUP BY✓ Tested
Count rows satisfying separate conditions
Postgres: SUM over CASE expressions calculates several conditional counts in one scan.
Postgres✓ Tested
Count the rows in a table
Postgres: COUNT(*) includes every row, including rows with NULL columns.
Postgres✓ Tested