PL/SQL is appropriate or required for querying object tables in Oracle in certain situations, such as:
- When complex business logic is involved: If the querying of an object table involves complex business logic that cannot be expressed using standard SQL queries, PL/SQL may be required. PL/SQL allows developers to write complex algorithms and manipulate data in ways that would be difficult or impossible to do using SQL alone.
- When using user-defined types: If an object table contains user-defined types, PL/SQL may be required to manipulate the data. This is because SQL has limited support for user-defined types, and PL/SQL provides more flexibility and control over how the data is accessed and manipulated.
- When using advanced features: Oracle provides advanced features such as pipelined table functions, which enable developers to process data in a streaming fashion, and row-level security, which restricts access to specific rows in a table. These features often require the use of PL/SQL code to implement.
- When using dynamic SQL: If the query against an object table needs to be constructed dynamically at runtime, PL/SQL may be required. This is because SQL does not provide a way to dynamically generate queries, and PL/SQL must be used to generate the necessary SQL statements.
In summary, PL/SQL may be appropriate or required for querying object tables in Oracle when the querying involves complex business logic, user-defined types, advanced features, or dynamic SQL.
The central purpose of the Oracle PL/SQL language is to make it as easy and efficient as possible to query and change the contents of tables in a database. You must use the SQL language to access tables, and each time you do so, you use a cursor to execute your task.
Question:What is a cursor?
A cursor
- is a pointer to a private SQL area that stores information about the processing of a SELECT or
- (DML)data manipulation language statement (INSERT, UPDATE, DELETE, or MERGE).
Cursor management of DML statements is handled by Oracle Database,
but PL/SQL offers several ways to define and manipulate cursors to execute SELECT statements.