Author: admin
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Common Aggregate Functions
In Oracle, the most commonly used aggregate functions are SUM(), AVG(), COUNT(), MIN(), and MAX(). Each of these functions serves a distinct purpose and can be applied to different types of data. The SUM() function totals numeric values, while AVG() calculates the mean. The COUNT() function counts rows or non-null entries, making it versatile for…
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Definition of Aggregate Functions
Aggregate functions in Oracle Database are special functions that process a set of values and return a single summary value. They are crucial for data analysis, allowing users to derive meaningful insights from large datasets. By performing operations such as summation, averaging, and counting, these functions simplify complex data into understandable summaries. This is particularly…
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Object Oriented
In this chapter, we will discuss Object-Oriented PL/SQL. PL/SQL allows defining an object type, which helps in designing object-oriented database in Oracle. An object type allows you to create composite types. Using objects allow you to implement real world objects with specific structure of data and methods for operating it. Objects have attributes and methods.…
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DBMS Output
In this chapter, we will discuss the DBMS Output in PL/SQL. The DBMS_OUTPUT is a built-in package that enables you to display output, debugging information, and send messages from PL/SQL blocks, subprograms, packages, and triggers. We have already used this package throughout our tutorial. Let us look at a small code snippet that will display all the…
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Date & Time
In this chapter, we will discuss the Date and Time in PL/SQL. There are two classes of date and time related data types in PL/SQL − The Datetime data types are − The Interval data types are − Field Values for Datetime and Interval Data Types Both datetime and interval data types consist of fields. The values of these fields…
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Transactions
In this chapter, we will discuss the transactions in PL/SQL. A database transaction is an atomic unit of work that may consist of one or more related SQL statements. It is called atomic because the database modifications brought about by the SQL statements that constitute a transaction can collectively be either committed, i.e., made permanent to the…
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Collections
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…
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Packages
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…
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Triggers
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…
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Exceptions
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…