Valli questions

Valli answers

• Joining sums of different periods from the same data set
• How to Select a substring in Oracle SQL
• ORA-00909: invalid number of arguments
• Sql conditional insert (insert value if not null or insert null)
• How to delete a lot of records from SQL database fast?
• Logic to check if exact ids are present in a group in SQL Server
• How to count different values into different rows in SQL efficiently?