Fahmi questions

Fahmi answers

• Rows with multiple corresponding values in the same table
• Select timestamp for one date and for a period time on the same field in one query
• Return null if value does not exist
• First 5 rows summed per ref per type, all others equal 1, grouped by a team ID
• LEFT OUTER JOIN with WHERE clause on 2nd table, not effecting 1st table
• Min() and Max() based on partition in sql server
• PostgreSQL removing duplicates without id or unique_key [duplicate]
• SUM value group by columns but do not 'aggregate' possible?
• Select users having required roles only
• How to merge multiple rows into one row with filtering rules in SQL Server