File Name: difference between procedure and function in oracle 10g .zip
- Oracle Function
- Advanced SQL Functions in Oracle 10g - Earp
- Microsoft SQL Server vs. Oracle: The Same, But Different?
In reality, you would only put a procedure into a WITH clause if you planned to call the procedure from a function in the declaration section. Any attempt to use it results in compilation errors, as shown below. Create a regular function to use as a comparison.
A function is a subprogram that is used to return a single value. You must declare and define a function before invoking it. It can be declared and defined at a same time or can be declared first and defined later in the same block. You must have define some parametrs before creating a procedure or a function. These parameters are.
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This page intentionally left blank. Contents Preface. The Result Set. Repetition Character. When programmers use SQL in Oracle, they inevitably look for easier and new ways to handle queries. What is needed is a way to introduce SQL users to the new features of Oracle 10g concisely and systematically so that database programmers can take full advantage of the newer capabilities. This book hopes to meet this need by exploring some common new SQL features.
Each chapter includes numerous working examples, and Oracle users can run these examples as they read and work through the book. Also, many books on Oracle 10g present the language syntax alone with no in-depth explanation, analysis, or examples.
In this book, we present not only the syntax for new features and functions, but also a thorough clarification and breakdown of the different functions, along with examples of ways they can and should be used.
Audience and Coverage This book is meant to be used by Oracle professionals as well as students, but it is not a SQL primer. It is meant for those famil- iar with SQL programming since most of the topics present not only the syntax, queries, and answers, but also have an analytical programming perspective to them. This book will allow the Oracle user to use SQL in new and exciting ways.
This book contains nine chapters. It begins by reviewing some of the common SQL functions and techniques to help transition into the newer tools of Oracle 10g. Chapter 1 reviews common Oracle func- tions. Chapter 7 covers the new regular expressions and string functions. Chapter 8 discusses collections and object-oriented features of Oracle 10g.
Chapter 9 introduces by example the bridges between SQL and XML, one of the most important topics Ora- cle professionals are expected to know today. This book also has two appendices. Appendix A illustrates string functions with examples, and Appen- dix B gives examples of some important statistical functions available in Oracle 10g. The book can be considered a starting point for research using some of the advanced topics since the subjects are discussed at length with examples and sample outputs.
Query development is approached from a logical standpoint, and in many areas perfor- mance implications of the queries are also discussed. We would also like to express our gratitude to Dr. Wes Little on the same endeavor. Our sincere thanks also goes to Dr. Ed Rodgers for his con- tinuing support and encouragement throughout the years.
We also appreciate Dr. Leonard Ter Haar, chair of the computer science department, for his advice, guidance, and support, and encouraging us to complete this book. Last, but not least, we would like to thank our fellow faculty members Dr. Jim Bezdek and Dr. Norman Wilde for their continuous support and encouragement. Introduction With the advent of new features added to SQL in Ora- cle 10g, we thought that some collection of material related to the newer query mechanisms was in order.
We have also briefly reviewed some older tools that will help transition to the new material. We rely heavily on examples, as most SQL programmers can and do adapt examples to other problems quickly. More specifically, some knowledge of Oracle functions is desirable, although some common func- tions are reviewed in Chapter 1. Functions have been refined and expanded as Oracle versions have evolved, culminating with the latest in Oracle 10g — analytical functions, MODEL statements, and regular expres- sions.
Some knowledge of spreadsheets is helpful in digesting this material. The analytical functions and MODEL statements provide convenient ways to dis- play and use data in a manner similar to a spreadsheet.
We review some common reporting functions in Chapter 2. The way we develop queries in SQL is often by begin- ning with a simple command and then building upon it until the answer is found. There are different approaches to building queries in SQL as in any other language. One way is to build for a result using logical, intermediate steps.
A second way to build SQL queries is for performance. In a real-world environment with large tables, performance usually becomes an issue on often-run commands. Even in the development of que- ries, performance issues may arise. The way this material is approached is less from the performance perspective and more from the logical, developmental viewpoint. Once a result is obtained, if the query is to be rerun, it is most appropriate to tune the query for performance by examining the way it was done and perhaps look for alternatives, e.
To develop queries, we will often find a result set and then use that result set to move to the next part of the query. If the intermediate result is faulty, then we correct and refine before we move on.
Some might argue that we overuse aliases, but we believe that it makes a query more meaningful, easier to debug, and more available for change in the future. As well, in deference to precedence rules and defaults, when a programmer uses aliases, he is very clear about what the aliases meant when he wrote the query in the first place. For example, using a simple calculator, we commonly use the square root function to compute the square root of some number.
In this case, the square root key on the calculator calls the square root function and the number in the display is transformed into its square root value. For the sake of defining the scope of this discussion, we also consider the square root key on a calculator as a one-to-one function. By one-to-one we mean that if one positive number is furnished, then one square root results from pressing the square root key — a one-to- one transformation.
Answer is called the range of the function. Oftentimes in computer situations, there is also an upper limit on the domain and range, but theoretically, there is no upper limit in algebra. The lower limit on the domain is zero as the square root of negative num- bers is undefined unless one ventures into the area of complex numbers, which is beyond the scope of this discussion. Almost any programming language uses functions similar to those found on calculators.
In fact, most pro- gramming languages go far beyond the calculator functions. In this chapter, we selectively illustrate several functions in each of these categories. We start by discussing simple SQL functions.
To illustrate the above square root function, suppose that a table named Measurement contained a series of numeric measured values like this: Subject Value First Common Numerical Manipulation Functions These are functions that are commonly used in numeri- cal manipulations. Examples of common numerical manipulation functions include: ABS — Returns the absolute value of a number or value. SQRT — Returns the square root of a number or value. SIGN — Returns 1 if the argument is positive; —1 if the argument is negative; and 0 if the argument is negative.
SIGN tells us whether the value is positive, negative, or zero. All of the common numerical functions take one argu- ment except MOD, which requires two. Functions can be nested; we can have a function operate on the value produced by another function. Examples of near value functions include: CEIL — Returns the ceiling value next highest integer above a number. Next we present illustrations and a discussion on the use of these near value functions. The near value func- tions will round off a value in different ways.
TRUNC simply removes decimal values. CEIL returns the next highest integer value regardless of the fraction. FLOOR returns the integer below the number, again regardless of whether positive or negative.
The second argument defaults to 0 as previously illustrated. Null Value Function This function is used if there are null values. The null value function is: NVL — Returns a substitute some other value if a value is null.
Advanced SQL Functions in Oracle 10g - Earp
Although there are many similarities between the two platforms, there are also a number of key differences. In this blog, I will be taking a look at several in particular, in the areas of their command language, how they handle transaction control and their organization of database objects. The main difference between the two languages is how they handle variables, stored procedures , and built-in functions. For the purposes of this article, a transaction can be defined as a group of operations or tasks that should be treated as a single unit. For instance, a collection of SQL queries modifying records that all must be updated at the same time, where for instance a failure to update any single records among the set should result in none of the records being updated.
This chapter describes some of the procedural capabilities of Oracle Database for application development, including:. It provides several features that make developing powerful database applications very convenient. An anonymous block consists of an optional declarative part, an executable part, and one or more optional exception handlers. This allows your application to prevent the server from issuing an error that could cause the client application to end. You can also define your own exceptions, declare them in the declaration part of a block, and define them in the exception part of the block. An example follows:.
Microsoft SQL Server vs. Oracle: The Same, But Different?
Oracle Database XE offers the capability to store programs in the database. This functionality enables commonly required code to be written and tested once and then accessed by any application that requires the code. Database-resident program units also ensure that the same processing is applied to the data when the code is invoked, making the development of applications easier and providing consistency between developers. The actions include creating, compiling, creating synonyms for, granting privileges on, and showing dependencies for these source types.
The call spec tells Oracle Database which Java method to invoke when a call is made. It also tells the database what type conversions to make for the arguments and return value. Stored procedures offer advantages in the areas of development, integrity, security, performance, and memory allocation. Oracle Database Application Developer's Guide - Fundamentals for more information on stored procedures, including how to call stored procedures and for information about registering external procedures.
В его ноздрях торчала английская булавка.
CREATE function in Oracle
Так и есть, примерно через каждые двадцать строк появляется произвольный набор четырех знаков. Сьюзан пробежала все их глазами. PFEE SESN RETM - Альфа-группы из четырех знаков, - задумчиво проговорила Сьюзан. - И частью программы они явно не являются. - Да бросьте вы это, - проворчал Джабба. - Хватаетесь за соломинку.
Ничего подобного ему никогда не приходилось видеть. На каждой руке всего по три пальца, скрюченных, искривленных. Но Беккера интересовало отнюдь не это уродство.
Он получил кольцо. До смерти напуганный, Двухцветный замотал головой: - Нет. - Viste el anillo. Ты видел кольцо. Двухцветный замер.
В АНБ он получил кличку Джабба и приобрел репутацию полубога. Он бродил по коридорам шифровалки, тушил бесконечные виртуальные пожары и проклинал слабоумие нерадивых невежд. Чатрукьян знал: как только Джабба узнает, что Стратмор обошел фильтры, разразится скандал. Какая разница? - подумал. - Я должен выполнять свои обязанности.
Он… это кольцо… он совал его нам в лицо, тыкал своими изуродованными пальцами. Он все протягивал к нам руку - чтобы мы взяли кольцо. Я не хотела брать, но мой спутник в конце концов его. А потом этот парень умер.