The FOR UPDATE clause in the SELECT statement can only be specified in the top level; subqueries cannot have this clause.Another Example of WHERE CURRENT OF Go through all Maths students and set all GPA’s under 4.0 to 4.0!
You can manipulate Oracle data flexibly and safely because PL/SQL fully supports all SQL data manipulation statements (except ), transaction control statements, functions, pseudocolumns, and operators.
It’s rare, in fact, that the data with which you are working is just a single value, so records and other composite datatypes are likely to figure prominently in your PL/SQL programs.
This article explores how you declare records, populate them with rows from a table, and even insert or change an entire row in a table by using a record.
It’s important to know when not to use cursor FOR loops.
My mentor told me that when querying data I should always use a cursor FOR loop, even for a single row lookup. It’s great to learn from others, and it’s especially wonderful when the lesson you learn is simple and easy to remember.
Tables are made up of rows of data, each consisting of one or more columns, so it stands to reason that Oracle Database would make it as easy as possible to work with those rows of data inside a PL/SQL program.