New to Oracle but familiar with MySQL?
Read on…
1. “Show create table” in Oracle?
sql> desc table
sql> select dbms_metadata.get_ddl( ‘TABLE’, ‘TABLE_NAME’, ‘OWNER’ ) from dual
note that, use table name and owner are case sensitive.
2. primary key with auto-increment
Oracle does not support primary key with auto-increment property. you need to do it with a sequence and trigger
create table table_name
(
table_nameid number(11,0) PRIMARY KEY NOT NULL,
...
);
— create sequence for primary key
create sequence table_name_seq
start with 1
increment by 1
nomaxvalue
NOCACHE;
— create trigger for primary key
CREATE OR REPLACE TRIGGER table_name_trg
BEFORE INSERT ON DBTABLE_OWNER.table_name
FOR EACH ROW
begin
select table_name_seq.nextval into :new.table_nameid from dual;
end;
/
COMMIT;
replace above table_name and DBTABLE_OWNER with the correct values.
3. Oracle Date column does not display time part/?
You need to turn the LongDate flag on.
4. Show tables in Oracle?
> SELECT owner, table_name FROM all_tables
5. select first N rows.
> select * from table where rownum < 10
6. List database links
SELECT owner,
db_link,
username,
host
FROM dba_db_links
ORDER BY owner, db_link