Oracle plsql by example benjamin rosenzweig, elena silvestrova rakhimov. We will show you how to create a plsql procedure and how to call it. Certain return types boolean, for example prevent a function from being called as part of a select. Ill use the word stored procedures more frequently than routines because its what weve used in the past, and what people expect us to use. The major difference between plsql function or procedure, function return always value where as procedure may or may not return value. Oracle plsql create function statement is used to create user defined function. Oracle stored procedure with examples dba republic. In plsql expressions, the function identifier acts like a. Procedure and functions in plsql linkedin slideshare. External procedures, triggers, and userdefined function. A procedure is a module performing one or more actions, it does not need to return any values.
The first parameter is number you want to list, the second parameter is the start value and the last parameter is the end value. It challenges you to learn oracle plsql by using it rather than by simply reading about it. This oracle tutorial explains how to create and drop procedures in oracleplsql with syntax and examples. In sql server, a procedure is a stored program that you can pass parameters into. On the sql commands page, enter the plsql code for the plsql procedure or function. Its also known as stored function or user function. The only difference is that function always returns a value. Plsql procedure allows you to encapsulate complex business logic and reuse it in both database layer and application layer.
A procedure is a group of plsql statements that you can call by name. A stored procedure or in simple a proc is a named plsql block which performs one or more specific task. Functions operators data types select query table joins stored procedures system stored procedures triggers views cursors backup restore transactions set statements constraints subquery statements variables. A procedure can be thought of as a function or a method. For that reason the oracle database also extends thecapabilities of the standard sql language with a uniqueprogramming language known as plsql. You can create your own stored procedures in sql server transactsql. The header consists of the name of the procedure and the parameters or variables passed to the procedure.
In my previous articles i have explained about sql interview questions with answers for different mnc companies. When you create a function or procedure, you have to define inoutinout parameters parameters. You can speed up plsql procedures by compiling them into native code residing in shared libraries. Plsql is a blockstructured language that enables developers to combine the power of sql with procedural statements. This tutorial will give you great understanding on plsql to proceed with. Best and worst practices an oracle white paper september 2008. All the sql server stored procedures are precompiled, and their execution plan is cached. Stored procedure interview questions pl sql stored.
Plsql allows the programmer to control the context area through the cursor. A block that has a name is called a stored procedure. Procedures functions execute as a plsql statement invoked. The sql server stored procedures saves a collection of one or group of statements stored in the sql server. However, it can return a successfailure status to the procedure that called it. A stored procedure is a set of sql statements that can be executed on the database. Select statement may return many records select empid, name, salary from employee where salary 120,000. These types of parameters are used to send values to stored procedures. You can use this technique with both the supplied oracle database plsql packages, and procedures you write yourself. Like a plsql function, a plsql procedure is a named block that does a specific task.
This chapter is going to cover important aspects of a plsql procedure and we will cover plsql function in next chapter. The only plsql code block keyword that is followed by a semicolon is the end keyword. The plsql stored procedure or simply a procedure is a plsql block which performs one or more specific tasks. This is similar to a procedure in other programming languages. User defined functions can be used as a part of an sql expression. The following are example of constrained variable definitions. A stored procedure is also a named plsql block the accepts some input in the form of parameters and performs some task and many or many not returns a value procedures are. Stored procedure is a database objects that stores the plsql code inside a. The call specification sometimes called call spec specifies a java method or a thirdgeneration language routine so that it can be called from sql and plsql. A procedure is a subprogram that performs a specific action.
Remember that this is not meant to bea fully fledged plsql development courseand, as such, we wont get into all the nitty grittyof programming with the plsql in the oracle databaseand instead focus on two basic examplesthat can get you started and. In plsql, we can pass parameters to procedures and functions in three ways. Plsql procedures create using create procedure statement. Procedures and functions are the subprograms which can be created and saved in the database as database objects. Procedure procedure parameter in plsql methods for passing parameters functions difference between function and procedure contents 2. Instructor now its time to see two examplesof creating a procedureand a function in the oracle database. The most tricky interview questions in pl sql are those with stored procedure interview questions. Thiss what a cursor want to execute a select statement get one record at a time. Plsql is one of three key programming languages embedded in the oracle database, along with sql itself and java. It is just like procedures in other programming languages.
A stored procedure allows for code that is run many times to be saved on the database and run at a later time, making it easier for yourself and other developers in the future. When you create a procedure or function, you may define parameters. Prior to joining ddr, he was a senior analyst in the languages division of oracle worldwide technical support, focusing on all of oracles language tools. Oracle creates context area for processing an sql statement which contains all information about the statement. For information on the syntax of the procedure declaration, see procedure declaration for each parameter, you specify.
Learning plsql procedure with examples is the best way to learn stored procedure. This causes the code block statements to be executed. Technically speaking, a plsql procedure is a named block stored as a schema object in the oracle database. Plsqls general syntax is based on that of ada and pascal programming language. A cursor holds the rows returned by the sql statement. Plsql code blocks are followed by a slash in the first position of the following line. Parts of a plsql subprogram each plsql subprogram has a name, and may have a parameter list. The header contains the name of the procedure and the parameters or variables passed to the procedure.
Just as you can in other languages, you can create your own procedures in oracle. Here is the list of some simple plsql programs examples. These types of parameters are used to get values from stored procedures. International technical support organization sql procedures, triggers, and functions on ibm db2 for i april 2016 sg24832600. The set of rows the cursor holds is referred as active set. He is also the bestselling author of oracle8i advanced plsql programming, oracle8 plsql programming, and oracle9i plsql. Or using conditional logic, or even using advanced typesand defining variables. Practical solutions connor mcdonald, with chaim katz, christopher beck, joel r. We have started this section for those beginner to intermediate who are familiar with sql and oracle. International technical support organization external procedures, triggers, and userdefined functions on ibm db2 for i april 2016 sg24650303. Granting privileges on an invokers rights subprogram. The procedures are translated into c code, then compiled with your usual c compiler and linked into the oracle database process. Procedures, functions and triggers slides anonymous plsql programs.
For example, oracle allows you to write stored procedures and triggers in java, etc. A stored procedure in plsql is nothing but a series of declarative sql statements which can be stored in the database catalogue. A procedure is a group of plsql statements that can be called by name. Database objects that can be referenced by other programs and can be used by other database users. Oracle database plsql users guide and reference oracle docs.