Cause: An invalid expression such as X
IN (SELECT A,B …) was used. When a [NOT]IN clause is used with a subquery,
it does not test for set membership. The number of expressions in the [NOT]IN
clause and the subquery select list must match. So, in the example above, the
subquery must specify at most one column.
Action: Change the subquery to select
only one column.

Relared Errors:
PLS-00320: the
declaration of the type of this expression is incomplete or
malformed
PLS-00321:
expression `string` is inappropriate as the left hand side of an
assignmen
PLS-00322:
declaration of a constant `string` must contain an initialization
assignme
PLS-00323:
subprogram or cursor `string` is declared in a package specification
and m
PLS-00324:
cursor attribute may not be applied to non-cursor
`string`
PLS-00325:
non-integral numeric literal string is inappropriate in this
context
PLS-00326: IN
clause must contain same number of expressions as subquery
PLS-00327:
string is not in SQL scope here
PLS-00328: A
subprogram body must be defined for the forward declaration of
string.
PLS-00329:
schema-level type has illegal reference to string