This document discusses stored procedures and functions in Oracle. It defines the key differences between procedures and functions. Procedures perform operations but do not return values, while functions return a value that can be used in computations. The document also provides the syntax for creating procedures and functions using PL/SQL and describes how to pass parameters to them.

1. PROCEDURE : Stored Procedures and Anonymous(External) Procedures
FUNCTION vs PROCEDURE : Function returns a value and the program uses the
returned value for computation while Procedure
doesn't return anything, it performs an operation.
- Procedures are always created even if errors are there but with an error
message.
- SHOW ERRORS command is used to see the errors.
- Source code of procedures and functions can be seen by using the command
"USER_SOURCE"
- select text from user_source where name='procedure_name or function_name'
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COMMANDS :
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1. CREATE PROCEDURE : To create a procedure
2. EXECUTE : To call a procedure with its name
3. OR REPLACE : Replaces the procedure if one exists with the same name
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CREATING A STORED PROCEDURE :
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CREATE OR REPLACE PROCEDURE procedure_name (parameters)
IS | AS
BEGIN
insert into table_name(parameters);
commits;
END;
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CREATING A STORED FUNCTION :
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CREATE OR REPLACE FUNCTION function_name (parameters)
RETURN datatype
IS | AS
BEGIN
executable statements;
RETURN value;
END;
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RECOMPILING :
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Oracle automatically compiles the invalid procedures and functions before
execution.
- To explicitly recompile the invalid procedures ot functions : ALTER PROCEDURE
procedure_name COMPILE;
- To see the status(valid/invalid) of a procedure : select status from
user_objects where object_name='procedure_name';
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PARAMETERS : Two types - FORMAL and ACTUAL
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FORMAL - parameters declared in defining the procedure
ACTUAL - parameters passed while calling the procedure
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PARAMTERS MODE : Three types - IN, OUT and IN OUT

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