How many types of procedures are there in PL SQL?
PL/SQL has two types of subprograms called procedures and functions. Generally, you use a procedure to perform an action and a function to compute a value.
PL/SQL has three categories of control statements: conditional selection statements, loop statements and sequential control statements.
A procedure or function is a schema object that logically groups a set of SQL and other PL/SQL programming language statements together to perform a specific task. Procedures and functions are created in a user's schema and stored in a database for continued use.
As Figure 1-1 shows, a PL/SQL block has three parts: a declarative part, an executable part, and an exception-handling part. (In PL/SQL, a warning or error condition is called an exception.) Only the executable part is required. The order of the parts is logical.
The Stored Procedures stage supports three types of procedures: Transform procedures. Source procedures. Target procedures.
Types of Procedures
Event-handling procedures are Sub procedures that execute in response to an event raised by user action or by an occurrence in a program. Function Procedures return a value to the calling code. They can perform other actions before returning.
DQL – Data Query Language. DML – Data Manipulation Language. DCL – Data Control Language. TCL – Transaction Control Language.
- Data Definition Language (DDL) Statements.
- Data Manipulation Language (DML) Statements.
- Transaction Control Statements.
- Session Control Statements.
- System Control Statement.
- Embedded SQL Statements.
- Data Definition Language (DDL) Statements.
- Data Manipulation Language (DML) Statements.
- Transaction Control Statements.
- Session Control Statements.
- System Control Statement.
- Embedded SQL Statements.
- procedure-name specifies the name of the procedure.
- [OR REPLACE] option allows the modification of an existing procedure.
- The optional parameter list contains name, mode and types of the parameters. ...
- procedure-body contains the executable part.
What are examples of procedures?
Installing a car battery is a simple procedure. What is the procedure for applying for a loan? New employees are taught the proper safety procedures. We must follow proper court procedure.
The syntax to create a procedure in Oracle is: CREATE [OR REPLACE] PROCEDURE procedure_name [ (parameter [,parameter]) ] IS [declaration_section] BEGIN executable_section [EXCEPTION exception_section] END [procedure_name]; When you create a procedure or function, you may define parameters.
There are three types of blocks that make up a PL/SQL program: Anonymous blocks: These are the unnamed PL/SQL blocks that are embedded within an application or are issued interactively. Procedures: These are the named PL/SQL blocks.
The basic program unit in PL/SQL is the block. A PL/SQL block is defined by the keywords DECLARE , BEGIN , EXCEPTION , and END . These keywords partition the block into a declarative part, an executable part, and an exception-handling part. Only the executable part is required.
A procedure has two parts: the specification and the body. The specification (spec for short) begins with the keyword PROCEDURE and ends with the procedure name or a parameter list. Parameter declarations are optional.
According to the model, procedures always consist of one or more of the following components: goals, prerequisites, actions and reactions, and unwanted states. ...
The MySQL Stored procedure parameter has three modes: IN, OUT, and INOUT. When we declare an IN type parameter, the application must pass an argument to the stored procedure. It is a default mode. The OUT type parameter, the stored procedure returns a final output generated by SQL Statements.
SQL procedures have the following major components: parameters, local variable declarations, and procedure body. Parameters are values that are passed into, or out of, a procedure.
Major surgery normally involves opening the body, allowing the surgeon access to the area where the work needs to be completed. It involves major trauma to the tissues, a high risk of infection, and an extended recovery period. Most major surgeries will leave a large scar.
A stored procedure is a prepared SQL code that you can save, so the code can be reused over and over again. So if you have an SQL query that you write over and over again, save it as a stored procedure, and then just call it to execute it.
How many methods are there in SQL?
Methods: Using PL/SQL.
In MySQL there are three main data types: string, numeric, and date and time.
There are two types of SQL functions, aggregate functions, and scalar(non-aggregate) functions. Aggregate functions operate on many records and produce a summary, works with GROUP BY whereas non-aggregate functions operate on each record independently.
1. Four types of joins: left, right, inner, and outer.
- CONSTRAINT clause.
- FOR UPDATE clause.
- FROM clause.
- GROUP BY clause.
- HAVING clause.
- ORDER BY clause.
- The result offset and fetch first clauses.
- USING clause.
...
Relational database query language
- MySQL.
- Oracle SQL.
- NuoDB.
The scope of SQL includes data query, data manipulation (insert, update, and delete), data definition (schema creation and modification), and data access control.
- Purpose and scope. States what the procedure accomplishes and the extent of its application.
- Preliminary requirements. Identifies any items such as documents, personnel, special tools, approvals, field preparations needed to perform the procedure.
- Warnings. ...
- Steps.
- Step 1: Align to business process. ...
- Step 2: Define the scope of the procedure. ...
- Step 3: Gather process information. ...
- Step 4: Create a standard structure for procedures. ...
- Step 5: Document the procedure, Review and Approve. ...
- Step 6: Communicate and provide training.
A procedure is a subprogram that performs a specific action. You specify the name of the procedure, its parameters, its local variables, and the BEGIN-END block that contains its code and handles any exceptions. A function is a subprogram that computes and returns a value.
Why are procedures used?
Procedures can be used throughout a program, making them simpler and quicker to code. Using procedures has an added benefit. If something needs to be changed in a procedure, it only needs to be changed once, within the procedure code. This change will then appear wherever the procedure is used in the program.
Procedures are action oriented. They outline steps to take, and the order in which they need to be taken. They're often instructional, and they may be used in training and orientation.
- Keep a Clear User Viewpoint. You should always be thinking about your end user when you write an SOP. ...
- Format Clearly. As well as being careful with language, process documentation should always use intuitive formatting. ...
- Keep Scope in Mind. ...
- Observe Roles and Impacts. ...
- Seek Authority and Approval.
A function would return the returning value/control to the code or calling function. A procedure, on the other hand, would return the control, but would not return any value to the calling function or the code. We cannot use the DML statements in a function, (functions such as Update, Delete, and Insert).
PL/SQL Source Files
One file has the default file extension . pks, and contains the package specification code.
PL/SQL is Oracle's version of SQL. Both are ANSI SQL compliant, but contain additional capabilities that are not in the standard. A Stored Procedure is a prepared SQL statement that is stored on the database server, and can be reused by calling it.
The block structure is divided into three different blocks which are declaration block, execution block and exception handling block. It is compulsory to specify the execution block.
In PL/SQL contexts, this statement can be compiled and executed by the data server. The anonymous block statement, which does not persist in the database, can consist of up to three sections: an optional declaration section, a mandatory executable section, and an optional exception section.
PL/SQL provides many predefined datatypes. For instance, you can choose from integer, floating point, character, Boolean, date, collection, reference, and large object (LOB) types. PL/SQL also lets you define your own subtypes.
| PL/SQL data type | SQL data type | Description |
|---|---|---|
| INT | INT | Signed four-byte integer numeric data |
| INTEGER | INTEGER | Signed four-byte integer numeric data |
| LONG | CLOB (32760) | Character large object data |
| LONG RAW | BLOB (32760) | Binary large object data |
What is type in PL SQL?
The %TYPE attribute, used in PL/SQL variable and parameter declarations, is supported by the data server. Use of this attribute ensures that type compatibility between table columns and PL/SQL variables is maintained.
Introduction to PL/SQL data types
PL/SQL has two kinds of data types: scalar and composite. The scalar types are types that store single values such as number, Boolean, character, and datetime whereas the composite types are types that store multiple values, for example, record and collection.
A cursor is a named control structure used by an application program to point to and select a row of data from a result set. Instead of executing a query all at once, you can use a cursor to read and process the query result set one row at a time.
An identifier is a name for a PL/SQL object, including any of the following: Constant or variable. Exception. Cursor. Program name: procedure, function, package, object type, trigger, etc.
