What is Pragma in PL SQL?

What is pragma exception in PL SQL?

The pragma EXCEPTION_INIT associates an exception name with an Oracle error number. You can intercept any ORA- error and write a specific handler for it instead of using the OTHERS handler. … You can use EXCEPTION_INIT in the declarative part of any PL/SQL block, subprogram, or package.

What is pragma autonomous transaction in PL SQL?

The AUTONOMOUS_TRANSACTION pragma changes the way a subprogram works within a transaction. A subprogram marked with this pragma can do SQL operations and commit or roll back those operations, without committing or rolling back the data in the main transaction. … Pragmas are processed at compile time, not at run time.

What is pragma in pragma?

Types of pragma directives in C

Instruction Description
OPTIMIZE To turn the optimization feature on or off
LOCALITY To name a coded subspace
OPT_LEVEL To set the level of optimization
HP_SHLIB_VERSION To create a version of a shared library routine

Why we are using pragma?

#pragma warn Directive: This directive is used to hide the warning messages which are displayed during compilation. This may be useful for us when we have a large program and we want to solve all the errors before looking on warnings then by using it we can focus on errors by hiding all warnings.

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How do you handle exceptions in PL SQL?

PL/SQL allows you to define your own exceptions according to the need of your program. A user-defined exception must be declared and then raised explicitly, using either a RAISE statement or the procedure DBMS_STANDARD. RAISE_APPLICATION_ERROR.

Where exceptions are used in PL SQL?

An error occurs during the program execution is called Exception in PL/SQL. PL/SQL facilitates programmers to catch such conditions using exception block in the program and an appropriate action is taken against the error condition. There are two type of exceptions: System-defined Exceptions.

Can we commit inside a trigger?

Any change that a trigger does is committed with the transaction that fired the trigger. So yes, the change done inside the trigger will be committed “automatically”. You can’t commit inside a trigger anyway.

What is transaction in PL SQL?

A transaction is a sequence of one or more SQL statements that Oracle Database treats as a unit: either all of the statements are performed, or none of them are. A transaction implicitly begins with any operation that obtains a TX lock: When a statement that modifies data is issued (e.g., insert, update, delete, merge)

Can we use autonomous transaction in function?

Using PRAGMA AUTONOMOUS_TRANSACTION in a Function

Because we included it in our function definition, everything in the body of the function happens in this separate transaction. Therefore, you can commit or rollback within the function, and it will not affect the calling transaction.

What is pragma Serially_reusable and why is it used?

The pragma SERIALLY_REUSABLE indicates that the package state is needed only for the duration of one call to the server (for example, a PL/SQL anonymous block, an OCI call to the database or a stored procedure call through a database link).

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What is pragma in database?

The PRAGMA statement is an SQL extension specific to SQLite and used to modify the operation of the SQLite library or to query the SQLite library for internal (non-table) data. … The pragma command is specific to SQLite and is not compatible with any other SQL database engine.

What is the meaning of pragma?

A pragma is a compiler directive that allows you to provide additional information to the compiler. This information can change compilation details that are not otherwise under your control. For example, the pack pragma affects the layout of data within a structure. Compiler pragmas are also called directives.

Where is pragma used?

The preprocessor directive #pragma is used to provide the additional information to the compiler in C/C++ language. This is used by the compiler to provide some special features.

How does pragma work?

#pragma is for compiler directives that are machine-specific or operating-system-specific, i.e. it tells the compiler to do something, set some option, take some action, override some default, etc. that may or may not apply to all machines and operating systems.

Should I use pragma once or Ifndef?

The fact of the matter is, #ifndef is standardized with standard behavior whereas #pragma once is not, and #ifndef also handles weird filesystem and search path corner cases whereas #pragma once can get very confused by certain things, leading to incorrect behavior which the programmer has no control over.