SQL 3 : Create type

Question

hello,
in an example using the object-relational model
I created the following type:
create type professeur_t as object (
+     nump varchar2(5),+
+     nomp varchar2(20),+
+     nbg integer);+
+     /+
create type "professeurs_t" as table of professeur_t;
create type eleve_t as object (
+     nume integer,+
+     nome varchar2(25),+
+     nomc varchar2(5)+
+     );+
+     /+
create type "eleves_t" as table of eleve_t;
when I try to create another type with the following command
create type ecole1_t as object (
+     nomc varchar2(5),+
+     eleves eleves_t,+
+     professeurs professeurs_t );+
+     /+
I get the following error message:
Warning: Type created with compilation errors
checking with:
select type_name from user_types ;
indicates that the type has been created
but when I try to create a table on this type with this command :
create table ecole1 of "ECOLE1_T" (primary key (nomc))
+     nested table eleves_t store as elev,+
+     nested table professeurs_t store as prof;+
I get:
ERROR at line 1:
ORA-00902: invalid datatype
Please if you have an idea about what to do? help me ?
Thank you in advance

Answer 1

Hi,
If you enclose the name of a type (or a table, or a cloumn, or anything else) in double-quotes when you create it, then you generally have to enclose it in double quotes and spell it exactly the same way (case-sensitive) every time you use it.
Lose the double-quotes:
create OR REPLACE type eleves_t as table of eleve_t;
create OR REPLACE type professeurs_t as table of professeur_t;
/All identifiers in Oracle are case-sensitive. You may not realize that because all unquoted code (that is, everything not in suingle-quotes, like 'foo', or double-quotes, like "bar") is converted to upper case before it is compiled.
So when you said
create type eleve_t ...the type that was created was ELEVE_T, all uppercase, exactly as it appears in all_objects.
When you referenced it like this:
create type "eleves_t" as table of eleve_t;there was no error, because all the unquoted code got capitalized before compiling, so it's as if you had said
CREATE TYPE "eleves_t" AS TABLE OF ELEVE_T;Because it was quoted, "eleves_t" was not capitalized.