 Related Questions Answer posted by Scott on 2005-05-25 18:30:04: TRUNCATE is a DDL command and cannot be rolled back. All of the memory space is released back to the server. DELETE is a DML command and can be rolled Latest Answer : DELETE is a logged operation on a per row basis. This means that the deletion of each row gets logged and physically deleted. You can DELETE any row that will not violate a constraint, while leaving the foreign key or any other contraint in place. ... Latest Answer : A query nested within another SQL statement is called a subquery. ... Latest Answer : In correlated subqueries, the information from the outer select statement participates as a condition in the inner select statement.Eg : Select deptno, ename, sal from emp a where sal> (select avg(sal) from emp b where ... Answer posted by Scott on 2005-05-25 18:32:51: UNION - the values of the first query are returned with the values of the second query eliminating duplicates. MINUS - the values of the first query Latest Answer : UNION: Take the common record once( No Duplicate)UNION ALL : Takes Duplicates alsoMinus: Result of first query - result of second queryexamleselect * from emp where rownum Answered by Scott on 2005-05-12 10:18:34: Constraints are found under the USER_CONSTRAINTS table. Latest Answer : Correction to some answers aboveUser_Constraints is a view and not a table ... Answer posted by Scott on 2005-05-25 18:39:48: When you create a sequence with CYCLE option, you are saying that when the sequence reaches its MAXVALUE, it will start over at the MINVALUE. This is not Latest Answer : when a sequence is created with CYCLE option, this mean that when a sequence reaches its MAXVALUE, it will start over at the MINVALUE. The CYCLE option is not wise for the primary key column.And when a sequence is created with NOCYCLE option, this ... Display the records between two range I know the nvl function only allows the same data type(ie. number or char or date Nvl(comm, 0)), if commission is null then the text “Not Applicable” want to display, instead of blank space. How do I write the query Answer posted by Scott on 2005-05-25 18:41:26: From the SQL> prompt, type the following: select * from v$version; Latest Answer : Just type define on your sql prompt ..you will get required info.. ... Latest Answer : NVLselect empno, ename, mgr, nvl(to_char(mgr),'no manager') from emp; ... Answer posted by Scott on 2005-05-25 18:43:29: SELECT rownum, rowid FROM sometable Latest Answer : Besides these, the other pseudo columns are: user,uid ...
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