PLS Error Codes

INTERSECT and MINUS set operators are not ANSI

The predicates IS NULL and IS NOT NULL are defined only for column specifications

The keyword DISTINCT must be present in a COUNT(DISTINCT sim_expr)

FOR UPDATE clause

Name length cannot exceed 3.

In a set_function_specification- if DISTINCT is present- the expression must be a column_specification

Aliases

The set clause in an UPDATE statement requires a column name of length 1

Use instead of != or ~=

Subquery on right-hand-side in set clause