Anonymous PL/SQL block checked exception - plsql

Question

I'm trying to catch an exception within my anonymous PL/SQL block
DECLARE
...
BEGIN
FOR herstell_row IN (
...
)
LOOP
...
DECLARE
table_does_not_exists exception;
pragma exception_init( table_does_not_exists, -942 );
BEGIN
INSERT INTO SMART_MONITORING_MACHINE_NAV_B (
MACHINE,
NAVIGATION_LEVEL_ID
)
SELECT
old_binding.MACHINE,
pv_id
FROM
SMART_MACHINE_NAV_BINDING old_binding
WHERE
old_binding.NAVIGATION_LEVEL_ID = herstell_row.HENAME1;
EXCEPTION
WHEN table_does_not_exists THEN null;
END;
END LOOP;
END;
I know the table SMART_MACHINE_NAV_BINDING doesn't exist in my case, so I need the nested anonymous block to ignore its code. But I always get this error:
Error report -
ORA-06550: line 41, column 14:
PL/SQL: ORA-00942: table or view does not exist
ORA-06550: line 33, column 10:
PL/SQL: SQL Statement ignored

Answer 1

You can't compile code with non-existent table, but you can try to execute it using EXECUTE EMMEDIATE:
DECLARE
...
BEGIN
FOR herstell_row IN (
...
)
LOOP
...
DECLARE
table_does_not_exists exception;
pragma exception_init( table_does_not_exists, -942 );
BEGIN
execute immediate
'INSERT INTO SMART_MONITORING_MACHINE_NAV_B (
MACHINE,
NAVIGATION_LEVEL_ID
)
SELECT
old_binding.MACHINE,
pv_id
FROM
SMART_MACHINE_NAV_BINDING old_binding
WHERE
old_binding.NAVIGATION_LEVEL_ID = :P' using herstell_row.HENAME1;
EXCEPTION
WHEN table_does_not_exists THEN null;
END;
END LOOP;
END;
Also you don't need exceptions here, you can check existence of a table using system view:
declare
table_created number;
begin
select count(*)
into table_created
from all_tables
where table_name = ...
and owner = ...;
if table_created > 0 then
execute immediate 'insert into ...';
end if;
end;
More information about EXECUTE IMMEDIATE statement: http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/executeimmediate_statement.htm#LNPLS01317

Answer 2

Oracle does not know this error table_does_not_exists it is user defined, so you should handle in when others then, for eg.
Exception
When Others then
null;
-- or at this time you can raise your error table_does_not_exists
raise table_does_not_exists;
-- and handle it in another parent block
end;
Exception
when table_does_not_exists then
null;
end;