 Related Questions 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 What are the pre-requisites to modify datatype of a column and to add a column with NOT NULL constraint 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 Latest Answer : NVLselect empno, ename, mgr, nvl(to_char(mgr),'no manager') from emp; ... Join is a query which retrieves related columns or rows from multiple tables.Self Join - Joining the table with itself.Equi Join - Joining two tables by equating two common columns.Non-Equi Join Latest Answer : In Full Outer Join we get both matched and unmatched data from both the tables whereas Cartesian join is a join in which each row of one table is cross multiplied with each row of the second table ... Sub query is a query whose return values are used in filtering conditions of the main query. Latest Answer : Hi Guys,A subquery is a SELECT statement that is embedded in a clause of another SQL statement, Called the parent statement.The subquery (inner query) returns a value that is used by the parent statement. Using a nested subquery is equivalent to performing ... Correlated sub query is a sub query which has reference to the main query. Latest Answer : Hi Guys,The Oracle Server performs a correlated subquery when the subquery references a column from a table reffered to in the parent statement. A correlated subquery is evaluated once for each row processed by the parent statement. The parent statement ... INTERSECT returns all distinct rows selected by both queries.MINUS - returns all distinct rows selected by the first query but not by the second.UNION - returns all distinct rows selected by either Latest Answer : union: distinct result set of two queries.union all : result set of two or more queries including duplicatesminus: result set of first query "-" resultset of second queryintersect : common result set of both query; ...
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