This article has multiple issues. Unsourced material may be pl sql documentation pdf and removed. SQL functionality with each successive release of
This article has multiple issues. Unsourced material may be pl sql documentation pdf and removed.
SQL functionality with each successive release of the Oracle Database. SQL units such as procedures, functions, packages, types, and triggers, which are stored in the database for reuse by applications that use any of the Oracle Database programmatic interfaces. SQL also resembles Pascal in several aspects. Such objects can also persist as column values in Oracle database tables. SQLite API by including a version of SQLite in Berkeley DB.
SQL code on Berkeley DB. One can use control statements like decision making, iterative control if only SQL is to be used. SQL is basically a procedural language, which provides functionality of decision making, iteration and many more features like other procedural programming languages. SQL source code that is compiled, developed and ultimately executed on the database.
SQL source program is the block, which groups together related declarations and statements. SQL block is defined by the keywords DECLARE, BEGIN, EXCEPTION, and END. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. The declaration section is optional and may be used to define and initialize constants and variables. The optional exception-handling part is used to handle run time errors.
Only the executable part is required. A block can have a label. The interactive tool or program runs the block once. SQL function is generally to compute and return a single value. User-defined functions supplement the built-in functions provided by Oracle Corporation. A function should only use the default IN type of parameter.
The only out value from the function should be the value it returns. Procedures resemble functions in that they are named program units that can be invoked repeatedly. Another difference is that the procedure can return multiple values whereas a function should only return a single value. The procedure begins with a mandatory heading part to hold the procedure name and optionally the procedure parameter list. Email address is too long.
The example above shows a standalone procedure – this type of procedure is created and stored in a database schema using the CREATE PROCEDURE statement. SQL package – this is called a Package Procedure. SQL anonymous block is called a nested procedure. Procedures can have three types of parameters: IN, OUT and IN OUT. An IN parameter is used as input only.
An IN parameter is passed by reference, though it can be changed by the inactive program. An OUT parameter is initially NULL. The program assigns the parameter a value and that value is returned to the calling program. An IN OUT parameter may or may not have an initial value.
That initial value may or may not be modified by the called program. SQL table and record TYPE statements, constants, cursors, etc. The use of packages promotes re-use of code. Packages are composed of the package specification and an optional package body.