T-SQL what does "<tablename> is not accessible in this context" mean? (SQL Code: 1001042)

Question

Using Sybase IQ 12.5,

When I try to insert the result of a stored proc into a table like this:

INSERT mytable (column1, column2, column3)
SELECT column1, column2, column3
FROM (myproc('AAA'))

I get the following:

ASA Error -1001042: Table, 'mytable', is not accessible in this context. 

The Sybase website has no further explanation

Answer 1

Problem was caused by my target table having a check constraint.

Here's an example to recreate the problem:

create table mytable (column1 int, 
    column2 int, 
    column3 int CHECK (column3 in (1,2,3)));

create procedure myproc( parm varchar(10))
  result ( column1 int, column2 int, column3 int)
  begin
     select 1,2,3;
 end;
INSERT mytable (column1, column2, column3)
  SELECT column1, column2, column3
  FROM (myproc('AAA'));