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There can be any number of parameters in plsql programming envoirement
Each parameters has a mode and a type. The possible modes are IN (read-only), OUT (write-only), and INOUT (read and write).
There can be any number of parameters in plsql programming envoirement
Each parameters has a mode and a type. The possible modes are IN (read-only), OUT (write-only), and INOUT (read and write).
IN, OUT and INOUT Modes
Values are passed to a procedure in three modes; IN, OUT and INOUT. The mode
which a variable is passed defines how the variables can be used inside the
procedure.
IN Mode (Read Only)
Default By operation
IN mode can be read and used by the procedure/function but can not be changed and it cannot be assigned a value(except Default) in an operation. Variables passed using IN mode can be considered as a constant. It is recommended for maintainability reasons to always define the variable passing
mode when you define the variable.
OUT Mode(write-Only)
A variable passed in OUT mode is used to pass information back from the
procedure to the calling program. It is a write-only variable and has no value
until the block assigns it a value. Internally, an OUT variable is created and
not initialized when the procedure is called. When the procedure ends, the
variable value (upon ending) is copied to the variable passed in the call. As
such, a variable passed in OUT mode can not be assigned a default value nor can
it be read inside the procedure. Because the variable value is copied back to
the passed variable when the procedure terminates, the calling code can not pass
an OUT variable a literal value. If the procedure raises an exception that is
not caught, it will result in the OUT variable not being copied when the
procedure terminates.
INOUT, for example, means that the parameter will receive a value and return
another
INOUT Mode
A variable passed in INOUT mode has characteristics of both the IN and the OUT
mode. The variable value is passed in and can be read by the procedure. The
procedure can also change the value and it will be copied back to the passed
variable when the procedure completes. Like a variable passed in OUT mode, an
INOUT variable can not have a default value and can not be passed as a literal.
If the procedure terminates abnormally (as in an exception) the INOUT variable
will not be copied back to the variable passed in.
Consider The Following 2 Example and Analyse the the cause of error...Read the above to understand why error incase you need more help POST ON FORUM OF GO4ORACLE.COM FOR ADMIN OR WEBMASTER TO REPLY
create or replace procedure demo1
(a in number := 10,
b in number := 20)
as
begin
n_1 := n_2 + 30;
end;
/
create or replace procedure demo2
(a in number := 10,
b in number := 20
c out number :=30)
as
begin
null;
end;
/
Note : Never Use Contrained parameter declaration while declaring any paramenter in a
plsql programs which are being invoked.For example, CHAR(10) and
VARCHAR(20) are illegal; CHAR or VARCHAR should be used instead.The actual
length of a parameter depends on the corresponding argument that is passed in
when the procedure is invoked.
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manvar.khan
dubey
