Results for “GROUP BY”
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 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 whitespace-separated words
Linux Commands: Use wc -w with standard input to omit the filename column.
Linux Commands✓ Tested
Detect invalid UTF-8 data
Detect invalid UTF-8 data in a complete Rust program using the standard library.
Rust✓ Tested
Distinguish row count from non-null value count
SQL: COUNT(*) includes every row while COUNT(column) skips NULL values.
SQL✓ Tested
Distinguish row count from non-null value count
SQL Server: COUNT(*) includes every row while COUNT(column) skips NULL values.
SQL Server✓ Tested