Beggining SQL Question Package Question

Question

After creating this bit of code for c_Pi
SQL> create or replace package MATH_CONSTANTS is
c_Pi constant number := 3.14159265; end MATH_CONSTANTS;
Create an unnamed block of code which prompts the user for a single numeric parameter, v_radius. This module should calculate the area of a circle using a radius equal to the inputted value along with c_Pi from the MATH_CONSTANTS package and subsequently display this information in a meaningful manner to the user.
Essentially how would I be able to take the user input and put it in a manner meaningful to the user (i.e. show it in a DBMS_OUTPUT.PUT_LINE(V_radius))
Also
For this following code, will it work and if not how should it be changed around?
Create or Replace Package OCTOBER12LAB As
procedure CONVERT(convID IN NUMBER, Measure IN NUMBER); end OCTOBER12LAB;
Create or Replace Package Body OCTOBER12LAB As
Procedure convert(convID IN NUMBER, Measure IN NUMBER) Is
V_Output Varchar2(50);
Begin
If convID = 1 Then
V_Output := FeetToYards(Measure);
elsIf convID = 2 Then
V_Output := YardsToFeet(Measure);
End If;
DBMS_OUTPUT.PUT_LINE(V_Output);
End convert;
Function FeetToYards(Measure IN NUMBER) return varchar2 Is
V_Total NUMBER(30,10); V_Output Varchar2(50);
Begin V_Total := Measure/3; V_Output := Measure || ' Feet equals ' || V_Total || ' Yards'; Return V_Output; End FeetToYards;
Function YardsToFeet(Measure IN NUMBER) return varchar2 Is
V_Total NUMBER(30,10); V_Output Varchar2(50);
Begin V_Total := Measure * 3; V_Output := Measure || ' Yard(s) equals ' || V_Total || ' Feet'; Return V_Output; End YardsToFeet;
End OCTOBER12LAB;
Begin
OCTOBER12LAB.convert(1,3);
OCTOBER12LAB.convert(2,2);
OCTOBER12LAB.convert(1,5); End;
Thanks in advance for your help.

Answer 1

Hi
Welcome to the forum!
966784 wrote:
After creating this bit of code for c_Pi
SQL> create or replace package MATH_CONSTANTS is
c_Pi constant number := 3.14159265; end MATH_CONSTANTS;
Create an unnamed block of code which prompts the user for a single numeric parameter, v_radius. This module should calculate the area of a circle using a radius equal to the inputted value along with c_Pi from the MATH_CONSTANTS package and subsequently display this information in a meaningful manner to the user.
Essentially how would I be able to take the user input and put it in a manner meaningful to the user (i.e. show it in a DBMS_OUTPUT.PUT_LINE(V_radius))If this is a homework assignment, ask your teacher for clarification of what this means.
PL/SQL has no mechanism for promting the user and getting keyboard input. You'll have to do that through your front end. If you're using SQL*Plus, you can use the SQL*Plus ACCEPT command to prompt the user, get input and store it in a substitution variable.
Also
For this following code, will it work Try it and see.
and if not how should it be changed around?
Create or Replace Package OCTOBER12LAB As
procedure CONVERT(convID IN NUMBER, Measure IN NUMBER); end OCTOBER12LAB;
Create or Replace Package Body OCTOBER12LAB As
Procedure convert(convID IN NUMBER, Measure IN NUMBER) Is
V_Output Varchar2(50);
Begin
If convID = 1 Then
V_Output := FeetToYards(Measure);
elsIf convID = 2 Then
V_Output := YardsToFeet(Measure);
End If;
DBMS_OUTPUT.PUT_LINE(V_Output);
End convert;
Function FeetToYards(Measure IN NUMBER) return varchar2 Is
V_Total NUMBER(30,10); V_Output Varchar2(50);
Begin V_Total := Measure/3; V_Output := Measure || ' Feet equals ' || V_Total || ' Yards'; Return V_Output; End FeetToYards;
Function YardsToFeet(Measure IN NUMBER) return varchar2 Is
V_Total NUMBER(30,10); V_Output Varchar2(50);
Begin V_Total := Measure * 3; V_Output := Measure || ' Yard(s) equals ' || V_Total || ' Feet'; Return V_Output; End YardsToFeet;
End OCTOBER12LAB;Never write, let alone post, unfomatted code.
Which do you think is easier to read and understand? The package spec you posted above, or the version below? Which do you think will result in fewer bugs? If there are bugs, which do you think will be help you find them better? Which do you think will encourage people on this form to read and understand your questions?
Create or Replace Package Body OCTOBER12LAB As
Procedure convert ( convID     IN   NUMBER
              , Measure    IN   NUMBER
Is
    V_Output Varchar2(50);
Begin
    If convID = 1 Then
        V_Output := FeetToYards (Measure);
    elsIf convID = 2 Then
        V_Output := YardsToFeet (Measure);
    End If;
    DBMS_OUTPUT.PUT_LINE(V_Output);
End convert;
Function FeetToYards ( Measure   IN    NUMBER)
return       varchar2
Is
    V_Total     NUMBER (30, 10);
    V_Output     Varchar2 (50);
Begin
    V_Total := Measure / 3;
    V_Output := Measure || ' Feet equals '
                        || V_Total
               || ' Yards';
    Return V_Output;
End FeetToYar;
Function YardsToFeet ( Measure    IN    NUMBER)
return       varchar2
Is
    V_Total     NUMBER (30, 10);
    V_Output     Varchar2 (50);
Begin
    V_Total := Measure * 3;
    V_Output := Measure || ' Yard(s) equals '
                        || V_Total
               || ' Feet';
    Return V_Output;
End YardsFeet;
End OCTOBER12LAB;The difference between what you posted and what I posted is merely whitespace; I didn't change your code at all except for adding spaces and newlines.
Indent your code to show the extent of structural statements, like BEGIN and IF, and also to make long expressions (such as the multi-part || operations) easier to read and debug.
Noramlly, all functions are included in the package spec. If you didn't want users calling a function directly (say, for security reasons) then you include the function in the package body only. Is there any reason not to include these functions in the package spec?
When using dbms_output, remember to SET SERVEROUTPUT ON.
Begin
OCTOBER12LAB.convert(1,3);
OCTOBER12LAB.convert(2,2);
OCTOBER12LAB.convert(1,5); End;
Thanks in advance for your help.Edited by: Frank Kulash on Oct 21, 2012 6:54 PM