How I can create a table with oracle but with small characters, when I create a table with small characters it converts auto to capital characters.
Folding (non-quoted) table names to upper case is required by the ANSI SQL standard.
You can create tables (and columns) with lowercase names using a quoted identifier (again this follows the SQL standard):
CREATE TABLE "foo"
(
"id" integer,
"SomeColumn" varchar(100)
);
I would however strongly advise you, to not do that.
Once you have your tables created that way, you have to always use double quotes because any non-quoted name will (following the rules for SQL identifiers) again be folded to upper-case and thus won't match the name as it is stored in the system catalogs.
Therefor the following statement will not work:
SELECT id, somecolumn FROM foo;
You have to use a quoted identifier:
SELECT "id", "SomeColumn" FROM "foo";
For more details on (quoted) identifiers, please read the chapter Database Object Naming Rules in the manual.
Enclose table name in quotation marks ("
). Also create your table like this
create table "t" ( a number, b varchar2(10) );
Now your table name is t
in lowercase. You have to use quotation marks always, when you access your table. For example
select * from "t";
You can use same construct for other objects (columns, indexes, ...).
Anyway, SQL is case insensitive, you need a good reason to use case dependent object names.