Explicit cursors, PL-SQL Programming

Assignment Help:

Explicit Cursors

The set of rows returned by the query can include zero, one, or multiple rows, depending on how many rows meet your search criteria. Whenever a query returns a multiple row, you can explicitly declare the cursor to process the rows. Furthermore, you can declare a cursor in the declarative part of any PL/SQL subprogram, block, or package.

You use 3 commands to control the cursor: OPEN, FETCH, & CLOSE. At First, you initialize the cursor with the OPEN statement that identifies the result set. Then, you use the FETCH statement to recover the first row. You can execute FETCH frequently until all rows have been retrieved. When the final row has been processed, you discharge the cursor with the CLOSE statement. You can process few queries in parallel by declaring and opening the multiple cursors.


Related Discussions:- Explicit cursors

Check constraints in sql, CHECK Constraints in SQL A CHECK constraint ...

CHECK Constraints in SQL A CHECK constraint is a table constraint defined using the key word CHECK, as already illustrated in several examples in this chapter. In particular,

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

Special cases of projection, Special cases of projection This section ...

Special cases of projection This section describes the identity projection, r {ALL BUT}, and the projection on no attributes, r { }, which yields TABLE_DUM when r is empty, ot

Union all - sql, UNION ALL - SQL Further varieties of UNION arise when...

UNION ALL - SQL Further varieties of UNION arise when we replace the key word DISTINCT by ALL in any of the foregoing examples, as in Example. ALL specifies that if row r appe

S, Question 1. Update stock levels when the order is cancelled At times, c...

Question 1. Update stock levels when the order is cancelled At times, customers make mistakes in submitting their orders and call to cancel the order. Brewbean’s wants to create a

Updating variables, Updating Variables For assignment, SQL uses the ke...

Updating Variables For assignment, SQL uses the key word SET, as in SET X = X + 1 (read as "set X equal to X+1") rather than X: = X + 1 as found in many computer languages.

Package body in pl/sql, Package Body: The package specification is imp...

Package Body: The package specification is implemented by the package body. That is, the package body has the definition of every cursor and the subprogram declared in the pac

For-loop -iterative control, FOR-LOOP While the number of iterations thr...

FOR-LOOP While the number of iterations through a WHILE loop is unknown till the loop completes, then the number of iterations through a FOR loop is known before the loop is ent

Synonyms- naming conventions, Synonyms You can create the synonyms to pr...

Synonyms You can create the synonyms to provide location transparency for the remote schema objects like tables, views, sequences, stand-alone subprograms, and packages. Though,

Providing results of queries, Providing Results of Queries Expressing ...

Providing Results of Queries Expressing queries in SQL is the (big) subject. Here I present just a simple example to give you the flavour of things to come in those chapters.

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