MySQL error: "NUMBER" is not valid at this position, expecting: BIT, BOOL, BOOLEAN, DATE, TIME, ENUM

INSERT INTO `groups` (column_name) VALUES (column_value)

If debut>=fin then 
     set resultat = -2; 
     -- don't put "end if" here
else 
     -- do something else
end if;

If debut>=fin then 
     set resultat = -2; 
     -- don't put "end if" here
elseif fin>=debut then
     -- do something else
else
     -- do yet something else
end if;

if debut >= fin then
    -- do something
else if fin >= debut then        -- you start a new "if" here!
                                 -- notice the space between else and if
    -- do the else
     end if                      -- end the second if
end if                           -- end the first if

FROM
(
    s_samples
    WHERE sample_id = 'S0001'
) as t1

FROM (SELECT s.*
      FROM s_samples s
      WHERE s.sample_id = 'S0001'
     ) t1

CREATE [AGGREGATE] FUNCTION function_name RETURNS {STRING|INTEGER|REAL|DECIMAL}
    SONAME shared_library_name

DELIMITER //

DROP PROCEDURE IF EXISTS myProcedure //

CREATE PROCEDURE 
  myProcedure( dept_name char(20) )
BEGIN  
    select ID, name, dept_name, salary
    from instructor 
    where instructor.dept_name=dept_name;
   ;  
END 
//

DELIMITER ;

call myProcedure( 'CSE' )