Results for “base”
Small, practical examples. Search by task or narrow things down below.
Count distinct values within a result
SQL: COUNT DISTINCT counts distinct non-null values.
SQL✓ Tested
Count distinct values within a result
SQL Server: COUNT DISTINCT counts distinct non-null values.
SQL Server✓ Tested
Count distinct values within a result
Postgres: COUNT DISTINCT counts distinct non-null values.
Postgres✓ Tested
Count distinct values within a result
SQLite: COUNT DISTINCT counts distinct non-null values.
SQLite✓ Tested
Count rows per category
Aggregate rows sharing the same category.
GROUP BY✓ Tested
Count rows satisfying separate conditions
SQL: SUM over CASE expressions calculates several conditional counts in one scan.
SQL✓ Tested
Count rows satisfying separate conditions
SQL Server: SUM over CASE expressions calculates several conditional counts in one scan.
SQL Server✓ Tested
Count rows satisfying separate conditions
Postgres: SUM over CASE expressions calculates several conditional counts in one scan.
Postgres✓ Tested
Count rows satisfying separate conditions
SQLite: SUM over CASE expressions calculates several conditional counts in one scan.
SQLite✓ Tested
Count the rows in a table
SQL: COUNT(*) includes every row, including rows with NULL columns.
SQL✓ Tested
Count the rows in a table
SQL Server: COUNT(*) includes every row, including rows with NULL columns.
SQL Server✓ Tested
Create a table and insert its first row
SQL: Define column types and a primary key, then insert one row using an explicit column list.
SQL✓ Tested