CONTROL STATEMENTS

PL/SQL provides several control statements that allow you to implement conditional and iterative logic within your code.
Here are some of the commonly used control statements in PL/SQL:
IF Statement :
The ‘IF’ statement is used for conditional execution of code.
Syntax : 
    IF condition THEN
    -- Code to execute if the condition is true
    ELSE
    -- Code to execute if the condition is false
    END IF;
Example: 
    declare
    a number := 50;
    b number := 25;
    begin
    if (a>b) then
    dbms_output.put_line('A is greater');
    else
    dbms_output.put_line('B is greater');
    end if;
    end;
    /

    A is greater
    
    PL/SQL procedure successfully completed.
CASE Statement :
The CASE statement is used for selecting one of several alternatives.
Syntax : 
    CASE
    WHEN condition1 THEN
    -- Code for condition1
    WHEN condition2 THEN
        -- Code for condition2
    -- ...
    ELSE
        -- Code to execute if none of the conditions are true
    END CASE;
Example: 
    declare
    state char(2):='&state';
    begin
    case state
    when 'TN' then
    dbms_output.put_line('Welcome to'||'Tamil Nadu');
    when 'MP' then
    dbms_output.put_line('Welcome to'||'Madhya Pradesh');
    when 'KL' then
    dbms_output.put_line('Welcome to'||'Kerala');
    else
    dbms_output.put_line('Contacts customer care');
    end case;
    end;
    /

    Enter value for state: TN 
    old 2: state char(2):='&state'; 
    new 2: state char(2):='TN'; 
    Welcome to Tamil Nadu 

    PL/SQL procedure successfully completed.
Nested if..elsif..end if cont… 
    declare
    p_center varchar2(20):='¢er';
    p_place varchar2(20):='&place';
    P_name varchar2(20):='&name';
    begin
    if p_center='TESDB' then
    if p_place='MOGAPAIR' then
    dbms_output.put_line('Welcome to TESDB Mogapair! ‘||P_name);
    elsif p_place='VELACHERY' then
    dbms_output.put_line('Welcome to TESDB Velachery! ‘||P_name);
    else
    dbms_output.put_line('Welcome to TESDB '||p_name||'!');
    end if;
    else
    dbms_output.put_line('Sorry! '|| p_name||‘ Login Denied');
    end if;
    end;
    /

    Enter value for center: TESDB
    old 2: p_center varchar2(20):='¢er';
    new 2: p_center varchar2(20):='TESDB';
    Enter value for place: VELACHERY
    old 3: p_place varchar2(20):='&place';
    new 3: p_place varchar2(20):='VELACHERY';
    Enter value for name: Sakthi
    old 4: P_name varchar2(20):='&name';
    new 4: P_name varchar2(20):='Sakthi';
    Welcome to TESDB Ambatture! Sakthi


(PL/SQL - Looping Structures)