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In this chapter, we will discuss the Collections in PL/SQL. A collection is an ordered group of elements having the same data type. Each element is identified by a unique subscript that represents its position in the collection. PL/SQL provides three collection types − Oracle documentation provides the following characteristics for each type of collections…

In this chapter, we will discuss the Packages in PL/SQL. Packages are schema objects that groups logically related PL/SQL types, variables, and subprograms. A package will have two mandatory parts − Package Specification The specification is the interface to the package. It just DECLARES the types, variables, constants, exceptions, cursors, and subprograms that can be referenced from…

In this chapter, we will discuss Triggers in PL/SQL. Triggers are stored programs, which are automatically executed or fired when some events occur. Triggers are, in fact, written to be executed in response to any of the following events − Triggers can be defined on the table, view, schema, or database with which the event…

In this chapter, we will discuss Exceptions in PL/SQL. An exception is an error condition during a program execution. PL/SQL supports programmers to catch such conditions using EXCEPTION block in the program and an appropriate action is taken against the error condition. There are two types of exceptions − Syntax for Exception Handling The general syntax for…

In this chapter, we will discuss the cursors in PL/SQL. Oracle creates a memory area, known as the context area, for processing an SQL statement, which contains all the information needed for processing the statement; for example, the number of rows processed, etc. A cursor is a pointer to this context area. PL/SQL controls the context area…

In this chapter, we will discuss the functions in PL/SQL. A function is same as a procedure except that it returns a value. Therefore, all the discussions of the previous chapter are true for functions too. Creating a Function A standalone function is created using the CREATE FUNCTION statement. The simplified syntax for the CREATE OR REPLACE PROCEDURE statement…

In this chapter, we will discuss Procedures in PL/SQL. A subprogram is a program unit/module that performs a particular task. These subprograms are combined to form larger programs. This is basically called the ‘Modular design’. A subprogram can be invoked by another subprogram or program which is called the calling program. A subprogram can be created − At…

In this chapter, we will discuss arrays in PL/SQL. The PL/SQL programming language provides a data structure called the VARRAY, which can store a fixed-size sequential collection of elements of the same type. A varray is used to store an ordered collection of data, however it is often better to think of an array as a…

The string in PL/SQL is actually a sequence of characters with an optional size specification. The characters could be numeric, letters, blank, special characters or a combination of all. PL/SQL offers three kinds of strings − PL/SQL strings could be either variables or literals. A string literal is enclosed within quotation marks. For example, To…

In this chapter, we will discuss Loops in PL/SQL. There may be a situation when you need to execute a block of code several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on. Programming languages provide various control structures…