A relational database is a database that conforms to the relational model....

A pseudocolumn behaves like a table column, but is not actually stored in the table.

ROWNUM is a pseudocolumn (not a real column) that is available in a query. ROWNUM will be assigned the numbers 1, 2, 3,

VALIDATE_CONVERSION determines whether `expr` can be converted to the specified data type.

The SELECT INTO is actually a standard SQL query where the SELECT INTO clause is used to place the returned data into predefined...

In PL/SQL method with count(*) is unsafe.

The `SET DEFINE` command changes the prefix character used to mark substitution variables.

The %TYPE attribute lets use the datatype of a field, record, nested table, database column, or variable in your own declarations, rather than hardcoding the type names.

As discussed earlier, there are two types of cursors: Implicit cursors and explicit cursors. In this section, we will focus on explicit cursors and their functionality...