What are the differences between implicit and explicit cursors in PL/SQL, and when would you choose to use each one?

Differences between Implicit and Explicit Cursors in PL/SQL

Implicit and explicit cursors are two types of cursors used in PL/SQL to retrieve and process data from the database. Here are the key differences between them:

Implicit Cursors

Implicit cursors are automatically created by the Oracle database when a SQL statement is executed in PL/SQL. They are used for simple SQL statements like SELECT INTO, where only a single row is expected to be returned.

Explicit Cursors

Explicit cursors are declared by the developer in the PL/SQL code to explicitly control the retrieval and processing of multiple rows from the database. They are used for complex SQL statements that return multiple rows or when more control over the cursor is required.

When to use Implicit Cursors:

• When retrieving a single row from the database
• For simple SELECT INTO statements
• When minimal control over the cursor is needed

When to use Explicit Cursors:

• When retrieving multiple rows from the database
• For complex SQL statements with joins, calculations, or filtering
• When more control over the cursor is required, such as opening, fetching, and closing the cursor manually

Choosing between implicit and explicit cursors depends on the specific requirements of the task at hand. Implicit cursors are suitable for simple and straightforward queries, while explicit cursors offer more flexibility and control for handling complex data retrieval operations.