Updating pl sql
Of course the simpler way would be to delete and insert as select, but in my case I needed a solution with just updates.The trick is that when you do select * from a pair of tables with duplicate column names, the 2nd one will get named _1. If you omit the WHERE clause, all records in the table will be updated! The WHERE clause specifies which record(s) that should be updated.In addition, my related problem was that only some of the columns were modified and many rows had no edits to these columns, so I wanted to leave those alone - basically restore a subset of columns from a backup of the entire table.If you want to just restore all rows, skip the where clause.This section is targeted as a good starting point for those who are new to PL/SQL.However, if you are very familiar with the language and also want to glance through these tutorials as a refresher, you may even find something useful that you haven’t seen before.
Before getting started, we highly recommend setting up Oracle database in your system to help you practice and learn PL/SQL effectively.
This website provides you with a comprehensive PL/SQL tutorial that helps you learn PL/SQL quickly and easily with a lot of fun.
PL/SQL stands for Procedural Language extensions to the Structured Query Language (SQL).
This events will alternates between BEFORE and AFTER row level triggers.
4) Finally the AFTER statement level trigger fires.