Oracle cursor for updating in oracle

Instead, consider a “next page” paradigm, in which the page has a preset maximum number of rows and the query that retrieves the next set of rows includes a WHERE clause that specifies that range of rows.BULK COLLECT with LIMIT when you don’t know the upper limit.If you try to add a 13th month to this list, Oracle Database will raise an exception: Code Listing 2: Defining a varray type and declaring a variable DECLARE TYPE at_most_twelve_t IS VARRAY (12) OF VARCHAR2 (100); l_months at_most_twelve_t := at_most_twelve_t (' January' , ' February' , ' March' , ' April' , ' May' , ' June' , ' July' , ' August' , ' September' , ' October' , ' November' , ' December' ); Varrays offer a very nice mechanism when you need to retrieve multiple rows of data efficiently and the number of rows should never exceed a certain limit.Suppose, for example, that I have a table (training_months) of the months in a year in which I am available to provide training on the PL/SQL language.This upper limit is specified when the varray type is declared; it can also be modified afterward, if you are using Oracle Database 10 Release 2 or higher.

oracle cursor for updating in oracle-83oracle cursor for updating in oracle-8

Code Listing 1: Encapsulating SELECT INTO in a function PACKAGE employees_qp IS FUNCTION last_name (id_in IN employees.employee_id%TYPE) RETURN employees.last_name%TYPE; END employees_qp; PROCEDURE process_employee (id_in IN employees.employee_id%TYPE) IS l_last_name employees.last_name%TYPE; BEGIN l_last_name := employees_qp.last_name (id_in); END process_employee; With this approach, you are much more likely to reuse that SELECT INTO rather than write it repeatedly in your code.This technique will “work,” but the program will consume a dangerously large amount of per-session memory. Instead, switch to an associative array or nested table and use the LIMIT clause with BULK COLLECT (as described in the next section).By the way, if you are writing back-end code that serves up data to a stateless user interface, as is often the case with browser-based applications, you would never retrieve so many rows at once.BULK COLLECT into a varray when you know the upper limit.A varray is a collection that has an upper limit on the number of elements that can be defined in the collection.

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