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PLSQL Tips & Tricks for today

Tips
In Oracle, A primary key cannot contain a NULL value.
But try the below..

Create table t1
(
col1 varchar2(30) null,
col2 varchar2(40),
add constraint col1_pk PRIMARY KEY ( col1 )
);

--The above is created successfully

TRICK

To copy a large table , use Oracle hint APPEND with Insert statement as below.

Consider the table TABLE1 having huge set of records ( > 10M rows )..

Create table TABLE1_copy
as
Select *
from TABLE1
where 1=2;

Insert /*+append*/ into table1_copy
select * from table1;

commit;

Comments

Anonymous said…
looks like your misunderstood the Primary key concept. Your script enforces unique+not null constraint on the col1 primary key.
October 19, 2013 at 7:58 AM
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