Rownum - sql pseudocolumns, PL-SQL Programming

Assignment Help:

ROWNUM

The ROWNUM returns a number representing the order in which a row was selected from the table. The first row selected has a ROWNUM of 1; the second row has a ROWNUM of 2, and so on. If the SELECT statement involves an ORDER BY clause, then the ROWNUMs are assigned to the retrieved rows before the sort is complete.

You can use the ROWNUM in an UPDATE statement to assign exclusive values to each row in a table. You can also use ROWNUM in the WHERE clause of a SELECT statement to the limit the number of rows retrieved, as shown:

DECLARE

CURSOR c1 IS SELECT empno, sal FROM emp

WHERE sal > 2000 AND ROWNUM < 10; -- returns 10 rows

The value of ROWNUM increase only whenever a row is retrieved, so the only significant use of ROWNUM in a WHERE clause is

... WHERE ROWNUM < constant;


Related Discussions:- Rownum - sql pseudocolumns

Example of unwrap operator - sql, Example of UNWRAP Operator - SQL Exa...

Example of UNWRAP Operator - SQL Example here shows how unwrapping can be done in longhand in SQL. Example: Unwrapping in SQL Letting CONTACT_INFO_WRAPPED denote the res

Joining in sql, Joining in SQL Joining IS_CALLED and IS_ENROLLED_ON in...

Joining in SQL Joining IS_CALLED and IS_ENROLLED_ON in SQL SELECT * FROM IS_CALLED NATURAL JOIN IS_ENROLLED_ON This is an example of an SQL table expression. I have been

Procedures - syntax, Procedures The procedure is a subprogram which can...

Procedures The procedure is a subprogram which can take parameters and be invoked. Normally, you can use a procedure to perform an action. The procedure has 2 sections: the spe

Using inner join, Using INNER JOIN INNER JOIN is used to retrieve the ...

Using INNER JOIN INNER JOIN is used to retrieve the data from all tables listed based on a condition of equality listed after keyword ON. If the condition is not meet, rows ar

PROCEDURE, Create a procedure named DDPROJ_SP that retrieves project inform...

Create a procedure named DDPROJ_SP that retrieves project information for a specific project based on a project ID. The procedure should have two parameters: one to accept a projec

Delimiters, Delimiters A delimiter is a simple or compound symbol whi...

Delimiters A delimiter is a simple or compound symbol which has a special meaning to PL/SQL. For example, you use delimiters to symbolize an arithmetic operation like additio

Write a pl-sql program using the implicit cursor, Question: a) Given th...

Question: a) Given the following relation: Location(loc_id, bldg_code, room, capacity) The underlined field is a primary key. (i) Write a PL/SQL program using the impl

Cursor variables, Cursor Variables Similar to a cursor, cursor variable...

Cursor Variables Similar to a cursor, cursor variable points to the current row in the result set of a multi-row query. But, dissimilar a cursor, a cursor variable can be opene

Collections in pl sql, Collections:   The collection is an ordered gr...

Collections:   The collection is an ordered group of elements, all of similar type (for illustration, the grades for a class of students). Each element has an exclusive subsc

Other monadic - sql, Other monadic - SQL In 2VL there are just 4 (2 2 ...

Other monadic - SQL In 2VL there are just 4 (2 2 ) monadic operators, of which negation is really the only "useful" one. When a third truth value is introduced we have 27 (3 3

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd