PLSQL package

A package is a type that correlates all kinds of logic 、 Constant 、 Variable 、 Exception and subroutine combined pattern object . A package usually consists of two parts ： Package description and package body , But sometimes inclusions are not needed . Package specification ( Shorthand for spec) It's the API ; It declares the available types 、 Variable 、 Constant 、 abnormal 、 Cursors and subroutines , Inclusion body (Body) Partially and completely define cursors and subroutines , And implement the contents in the description .

As shown in the following example , We can consider the description part as an optional interface , And the inclusion is a " Black box ". We can debug it 、 Enhance or replace a package and change the interface differently ( Package specification ).

  We can SQL*Plus Use in CREATE PACKAGE Statement to create a package . The grammar is as follows ：

CREATE [ORREPLACE] PACKAGE package_name   [AUTHID { CURRENT_USER | DEFINER}]   { IS | AS}   [PRAGMASERIALLY_REUSABLE;]   [collection_type_definition ...]   [record_type_definition ...]   [subtype_definition ...]   [collection_declaration ...]   [constant_declaration ...]   [exception_declaration ...]   [object_declaration ...]   [record_declaration ...]   [variable_declaration ...]   [cursor_spec ...]   [function_spec ...]   [procedure_spec ...]   [call_spec ...]   [PRAGMARESTRICT_REFERENCES(assertions) ...] END [package_name]; [CREATE [ORREPLACE] PACKAGEBODY package_name { IS | AS}   [PRAGMASERIALLY_REUSABLE;]   [collection_type_definition ...]   [record_type_definition ...]   [subtype_definition ...]   [collection_declaration ...]   [constant_declaration ...]   [exception_declaration ...]   [object_declaration ...]   [record_declaration ...]   [variable_declaration ...]   [cursor_body ...]   [function_spec ...]   [procedure_spec ...]   [call_spec ...] [BEGIN   sequence_of_statements] END [package_name];]

The contents declared in the package description are public , Visible to the application . We must be in all other content ( In addition to the compilation instructions for naming a particular function ; Such compilation instructions must follow the function description ) Subroutines can be declared only after declaration .

The contents in the package have private , It implements the details defined in the description part , And invisible to the application . Follow closely The declaration part of the package body is an optional initialization part , It is used to initialize variables in the package .

AUTHID Statement determines whether all packaged subroutines are defined according to the permission of the definer ( Default ) Or the caller has permission to execute , Whether the schema object involved is resolved in the definer's schema or the caller's schema .

A call description allows us to Oracle Publish a in the data dictionary Java Method or external C function . Call the name of the handle program 、 Parameter types and return types map to their SQL copy (SQL counterpart) To release the program .

Package form ：
Package Described by the package （package Specification) And inclusion (package body) Two parts make up ; Package specification Partly equivalent to C In language .H file , The inclusion part is equivalent to C The language is aimed at .H Realized C file .

Package Commonly used SQL：
create or replace package—— Create a package
create or replace package body ——— Create enclaves
drop package———— Delete package
drop package body———— Delete inclusion

Package benefits ：
1、 modularization ： Generally, functions and processes with correlation are put into a Package in ;
2、 Easy to design ： You can write and compile the package description and package body respectively , Write and compile the package description first , In the preparation and description of the inclusion body ; This is beneficial In the division of labor and cooperation ;
3、 Information hiding ： The function description can appear in the package body , Only the functions and procedures that appear in the package description are the Package Of public ownership Functions and procedures , Can be called by functions in other packages , Otherwise, it is invisible to functions in other packages , Functions that do not appear in the package description section And processes are equivalent to private .
4、 Improved loading performance ： When Package When a function or procedure is called in , Whole Packege Is loaded into memory , It's time to do that Package When other functions in are called , Just read it directly from memory , Can reduce the number of disks IO, To improve performance . 
This feature also reminds We're not going to make Big Macs Package, Take whatever you need Functions are written in a Package in , This can lead to a serious waste of memory .
5、 heavy load ： One package The same name can be defined in 、 Functions or procedures with different parameters .

Package Forward declaration feature in ：
stay Package body in , Calling another function in a function （ It's also here Package in ）, Otherwise A function must be defined first ;

If you have to call a function defined in the program code , You can set this function as a public function , Explain in the package description section ;
 

/*
--      Date of creation : 2022-07-19
--         author : ebowtang
--     Function description : plsql Practice of bag , The package is written around three related tables , Simulate a series of school queries , increase , Delete and other functions 
--         object :  Student information sheet , League tables , The curriculum 
--  Other matters needing attention :
--  1,  This script file completely contains all the test code , You can choose to execute in the specified section 
--  2,  The module details used in the script writing and testing process are preserved , For reference ,
--      For example, you will see separate get_namelist01 Process code , Actually, the corresponding one is in the package get_grade_namelist, I verify it first, and then put it into the package .
*/

-- Define package specifications , The package specification will be used for the interface part of the application , For external calls 
CREATE OR REPLACE PACKAGE stu_pkg as

   ---- The three cursor variables of Fame point to the collection of all grades in high school 
   cursor cur_students_one is select * from students where grade = ' First year of high school ';
   cursor cur_students_two is select * from students where grade = ' Senior high school grade two ';
   cursor cur_students_three is select * from students where grade = ' Third year of high school ';

   -- A variable is used to save a record of the cursor 
   v_stu students%rowtype;
   
   -- Limit the number of people displayed 
   max_show_number integer := 100;
   
   -- Define the process : New student registration 
   PROCEDURE signup(p_stu_id number ,p_stu_name char,p_gender varchar2,p_age number,
                 p_grade varchar2,p_class varchar2,p_email varchar2,p_sdate DATE);
                 
   -- Define the process : Expel a student                   
   PROCEDURE expel_student( p_stu_id NUMBER );
   
   -- Implementation process : Get the specified grade 、 Before the grade of the designated discipline 100 ranking （ All semesters ）
   procedure get_grade_scores(p_grade varchar2 , p_course_name char );
   
   -- Implementation process : Get the test score statistics of the specified semester （ average , Total score , The highest , Lowest score ）, And rank according to the total score 
   procedure get_statistics_scores(p_grade varchar2,p_batch char );
   
   -- Query the evaluation level of students' grades （ distinguish ABCDE, Do not publish the value to students ）
   procedure get_evaluate(p_stu_id number,p_batch varchar2);
   
   -- Implementation function ： Modify the scores of designated students 
   function change_score ( p_score int, p_stu_id number,
		p_course varchar2, p_batch varchar2 ) return int;
		
   -- Implementation process ： Get the list of grades 
   procedure get_grade_namelist(p_grade varchar2);
   
   -- Implementation function ： The total score of one of the specified students 
   FUNCTION get_totalscore(p_stuid scores.student_id%type) RETURN scores.score_value%type;

END stu_pkg;

-- Implementation package 
CREATE OR REPLACE PACKAGE BODY stu_pkg AS
   -- Realize the specific realization of employing employees 
   PROCEDURE signup(p_stu_id number ,p_stu_name char,p_gender varchar2,p_age number,
                 p_grade varchar2,p_class varchar2,p_email varchar2,p_sdate DATE) IS
   begin
   -- Implementation process : New students register 
      INSERT INTO students VALUES(p_stu_id ,p_stu_name,p_gender,p_age,
      			p_grade,p_class,p_email,p_sdate); 
   END;       
   
   -- Implementation process : Expel a student                   
   PROCEDURE expel_student(p_stu_id NUMBER ) IS
   BEGIN
   -- from emp Delete employee information in the table 
      DELETE FROM scores WHERE student_id=p_stu_id;
      DELETE FROM students WHERE student_id=p_stu_id;
   END;    
   
   -- Implementation process : Get the specified grade 、 Before the grade of the designated discipline 100 ranking （ All semesters ）
   procedure get_grade_scores(p_grade varchar2 , p_course_name char ) is
   begin
		select student_name,grade,course_name,score_value,scores.batch
		from  students,scores,courses
		where scores.student_id = students.student_id 
			and courses.course_name = p_course_name 
			and courses.course_id = scores.course_id
			and students.grade = p_grade
		order by score_value desc
		limit max_show_number;
   END; 
   
   -- Implementation process : Get the test score statistics of the specified semester （ average , Total score , The highest , Lowest score ）, And rank according to the total score 
   procedure get_statistics_scores(p_grade varchar2,p_batch char ) is
   BEGIN
		select *
		from students,(
			select student_id as  Student ID,round(avg(score_value),1) as   average ,sum(score_value) as  Total score ,max(score_value) as  The highest ,min(score_value) as  Lowest score   
			from scores  
			group  by student_id,batch
			having  batch=p_batch
		)
		where grade = p_grade and students.student_id =  Student ID
		order by  Total score  desc ;
   END;
   
   -- Implementation process ： Query the evaluation level of students' grades （ distinguish ABCDE, Do not publish the value to students ）（ Fixed access to Mathematics ）
   procedure get_evaluate(p_stu_id number,p_batch varchar2) as 
		l_course_id varchar2;
		l_score number;
		l_grade varchar2;
		tempscore number := 0;
		l_course_name varchar2 := ' mathematics ';
   begin
		select course_id  into l_course_id
		from courses 
		where course_name= ' mathematics ' and category = ' Liberal arts ';
		
		select score_value into l_score 
		from scores
		where student_id =p_stu_id and course_id = l_course_id and batch=p_batch;
			
		if l_course_name = ' English ' or l_course_name = ' mathematics ' or l_course_name = ' Chinese language and literature ' then
			tempscore =l_score/150;
		else 
		    tempscore =l_score/100;
		end if;
		-- Different score segments are rated differently 
		CASE TRUE
	    WHEN tempscore < 1.0 and tempscore > 0.9  
	    	THEN l_grade ='A';
	    WHEN tempscore < 0.9 and tempscore > 0.8  
	    	THEN l_grade ='B';
	    WHEN tempscore < 0.8 and tempscore > 0.7  
	    	THEN l_grade ='C';
	    WHEN tempscore < 0.7 and tempscore > 0.6 
	    	THEN l_grade ='D';
	    ELSE l_grade ='E';
	  	END CASE;
	  	RAISE NOTICE 'your Score grade is:% %',l_score, l_grade;
	 END;
	 
	 -- Implementation function ： Revise student scores 
	 function change_score ( p_score int, p_stu_id number,
		p_course varchar2, p_batch varchar2 ) return int as 
	 begin
		if p_score > 150 or p_score < 0 then 
			return 0;
		end if;
		update scores set score_value=p_score 
		where student_id =p_stu_id and course_id =p_course and batch=p_batch;
		return 1;
	 end;
	 
	 -- Implementation process ： Get the list of grades 
	 procedure get_grade_namelist(p_grade varchar2) as 
	 begin
	  -- Open cursor 
	   if p_grade = ' First year of high school ' then
		   open cur_students_one;
		   -- Do it once fetch into  Let the cursor point to the first data 
		   fetch cur_students_one into v_stu;
		   --while loop , Conditions are cyclic conditions 
		   while cur_students_one%found loop
			  -- Print student information 
			  --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
			  RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
			  --fetch into Point the cursor to the next data 
			  fetch cur_students_one into v_stu;
		   end loop;
		   --dbms_output.put_line(cur_students_one%rowcount||'');
		   RAISE NOTICE 'Number of students is:%',cur_students_one%rowcount;
		   -- Close cursor 
			   close cur_students_one;
			   
		  elsif p_grade = ' Senior high school grade two ' then 
		  open cur_students_two;
		   -- Do it once fetch into  Let the cursor point to the first data 
		   fetch cur_students_two into v_stu;
		   --while loop , Conditions are cyclic conditions 
		   while cur_students_two%found loop
			  -- Print student information 
			  --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
			  RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
			  --fetch into Point the cursor to the next data 
			  fetch cur_students_two into v_stu;
		   end loop;
		   --dbms_output.put_line(cur_students_two%rowcount||'');
		   RAISE NOTICE 'Number of students is:%',cur_students_two%rowcount;
		   -- Close cursor 
			   close cur_students_two;
			   
		  elsif p_grade = ' Third year of high school ' then
		   open cur_students_three;
		   -- Do it once fetch into  Let the cursor point to the first data 
		   fetch cur_students_three into v_stu;
		   --while loop , Conditions are cyclic conditions 
		   while cur_students_three%found loop
			  -- Print student information 
			  --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
			  RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
			  --fetch into Point the cursor to the next data 
			  fetch cur_students_three into v_stu;
		   end loop;
		   --dbms_output.put_line(cur_students_three%rowcount||'');
		   RAISE NOTICE 'Number of students is:%',cur_students_three%rowcount;
		   -- Close cursor 
			   close cur_students_three;
		  else 
			   RAISE NOTICE 'your enter grade is error ';
			  end if;
		 end;
	 
	FUNCTION get_totalscore(p_stuid scores.student_id%type) RETURN scores.score_value%TYPE
	AS
		v_maxscore scores.score_value%type := 0;
	begin
		select sum(score_value) into v_maxscore
		from scores  
		group  by student_id,batch
		having  batch=' midsemester ' and student_id = p_stuid;
		
		RETURN v_maxscore;
	EXCEPTION
		WHEN NO_DATA_FOUND THEN
	 	RAISE NOTICE 'The student id is invalid';
	 	RETURN -1;
	END get_totalscore;
END stu_pkg;

-- Anonymous blocks perform package tests 
declare 
	l_grade char;
begin 
	-- Expulsion of students （ According to the student number ）
	stu_pkg.expel_student(2314);
	-- Register a student ( Constrained )
	stu_pkg.signup(2314,' Zhang Detian ',' male ',19,' First year of high school ',' Class eight ','[email protected]',SYSDATE);
	-- Count the student's scores （ Total score , Highest grade ）
	stu_pkg.get_statistics_scores(' Senior high school grade two ',' final exam ');
	-- Get grades （ABCDE）
	stu_pkg.get_evaluate(4324,' final exam ');
	-- Get the grade ranking of specified subjects 
	stu_pkg.get_grade_scores(' Third year of high school ',' Chinese language and literature ');
	-- Revise grades 
	select stu_pkg.change_score(141,2314,'02',' midsemester ') from dual;
	-- Verify whether the modification of student grades is successful 
	select score_value from scores where course_id='02' and student_id=2314;
	-- Test stored procedures written separately -- Realize grade list query ( Non package stored procedures )
	call get_namelist01(' First year of high school ');
	-- Test stored procedures written separately ( Non package stored procedures )
	stu_pkg.get_grade_namelist(' Third year of high school ');
	-- Get the total score of the designated student （ Entering an incorrect student number will detect an exception ）
	select stu_pkg.get_totalscore(2614) from dual;
end



---------------------plsql The modules of the package are tested separately -----------------------------


CREATE OR REPLACE FUNCTION get_totalscore(p_stuid scores.student_id%type) RETURN scores.score_value%TYPE
AS
	v_maxscore scores.score_value%type := 0;
begin
	select sum(score_value) into v_maxscore
	from scores  
	group  by student_id,batch
	having  batch=' midsemester ' and student_id = p_stuid;
	
	RETURN v_maxscore;
EXCEPTION
	WHEN NO_DATA_FOUND THEN
 	RAISE NOTICE 'The student id is invalid';
 	RETURN -1;
END get_totalscore;

-- test 
begin 
	--select * from scores;
	select get_totalscore(4324) from dual;
end

select sum(score_value)
	from scores  
	group  by student_id,batch
	having  batch=' midsemester ' and student_id = 2614;

select score_value
from scores  
where  batch=' midsemester ' and student_id = '2614' and course_id = 01;


-- Nested table 
CREATE OR REPLACE TYPE stu_arr_typ IS TABLE OF char(8);

create  or replace  procedure test01 as 
   stu_arr stu_arr_typ :=stu_arr_typ();
   CURSOR stu_cur IS SELECT student_name FROM students WHERE age > 19;
   --v_student_name students.student_name%type;
   v_student_name char(8);
   i               INTEGER := 0;
BEGIN     
   open stu_cur;
   fetch stu_cur into v_student_name;
   while stu_cur%found loop 
   	     RAISE NOTICE 'name list is % ',v_student_name;
   	     fetch stu_cur into v_student_name;
   end loop;
   close stu_cur;
END ;

-- test 
begin 
	call test01();
end

open stu_cur;
   fetch stu_cur into v_student_name;
   while stu_cur%found loop 
   	     stu_arr(i) := v_student_name;
   	     RAISE NOTICE 'name list is % ',stu_arr(i);
   	     i := i+1;
   	     fetch stu_cur into v_student_name;
   end loop;
   close stu_cur;
   
declare
  -- Claim a nested table type , Store string data 
  type tabType is table of varchar2(200);
  -- Name variable 
  tab1 tabType;
  tab2 tabType;
  -- Claim that a variable holds the subscript of the nested table 
  ind pls_integer;
begin
  -- Initialize nested tables 
  tab1:=tabType();
  -- Print nested tables tab1 The length of 
  --dbms_output.put_line('tab1 The length of '||tab1.count);
   	RAISE NOTICE 'tab2 The length of  % ',tab1.count;

  -- Initialize nested tables tab2
  tab2:=tabType('a','b','c','d');
   -- Print nested tables tab2 The length of 
  --dbms_output.put_line('tab2 The length of '||tab2.count);
 	RAISE NOTICE 'tab2 The length of  % ',tab2.count;
   --- Ergodic set 
   ind := 1;
   loop--loop loop 
      -- Print set elements 
      dbms_output.put_line(tab2(ind));
      -- Exit conditions 
      exit when ind=tab2.last;
      ind:=tab2.next(ind);
   end loop;
   
  for i in tab2.first..tab2.last loop--for loop 
    RAISE NOTICE 'tab2 is % ',tab2(i);
  end loop;
end;



DECLARE
  TYPE Roster IS TABLE OF VARCHAR2(15);  -- nested table type
 
  -- nested table variable initialized with constructor:
 
  names Roster := Roster('D Caruso', 'J Hamil', 'D Piro', 'R Singh');
 
  PROCEDURE print_names (heading VARCHAR2) IS
  BEGIN
    DBMS_OUTPUT.PUT_LINE(heading);
 
    FOR i IN names.FIRST .. names.LAST LOOP  -- For first to last element
      DBMS_OUTPUT.PUT_LINE(names(i));
    END LOOP;
 
    DBMS_OUTPUT.PUT_LINE('---');
  END;
  
BEGIN 
  print_names('Initial Values:');
 
  names(3) := 'P Perez';  -- Change value of one element
  print_names('Current Values:');
 
  names := Roster('A Jansen', 'B Gupta');  -- Change entire table
  print_names('Current Values:');
END;
/

-- Define three cursors to get grade data 
create  or replace  procedure get_namelist01(p_grade varchar2) as 
   -- Three cursors 
   cursor cur_students_one is select * from students where grade = ' First year of high school ';
   cursor cur_students_two is select * from students where grade = ' Senior high school grade two ';
   cursor cur_students_three is select * from students where grade = ' Third year of high school ';
   -- A variable is used to save a record of the cursor 
   v_stu students%rowtype;
begin
	  -- Open cursor 
   if p_grade = ' First year of high school ' then
	   open cur_students_one;
	   -- Do it once fetch into  Let the cursor point to the first data 
	   fetch cur_students_one into v_stu;
	   --while loop , Conditions are cyclic conditions 
	   while cur_students_one%found loop
	      -- Print student information 
	      --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
	      RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
	      --fetch into Point the cursor to the next data 
	      fetch cur_students_one into v_stu;
	   end loop;
	   --dbms_output.put_line(cur_students_one%rowcount||'');
	   RAISE NOTICE 'Number of students is:%',cur_students_one%rowcount;
	   -- Close cursor 
		   close cur_students_one;
		   
	  elsif p_grade = ' Senior high school grade two ' then 
	  open cur_students_two;
	   -- Do it once fetch into  Let the cursor point to the first data 
	   fetch cur_students_two into v_stu;
	   --while loop , Conditions are cyclic conditions 
	   while cur_students_two%found loop
	      -- Print student information 
	      --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
	      RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
	      --fetch into Point the cursor to the next data 
	      fetch cur_students_two into v_stu;
	   end loop;
	   --dbms_output.put_line(cur_students_two%rowcount||'');
	   RAISE NOTICE 'Number of students is:%',cur_students_two%rowcount;
	   -- Close cursor 
		   close cur_students_two;
		   
	  elsif p_grade = ' Third year of high school ' then
	   open cur_students_three;
	   -- Do it once fetch into  Let the cursor point to the first data 
	   fetch cur_students_three into v_stu;
	   --while loop , Conditions are cyclic conditions 
	   while cur_students_three%found loop
	      -- Print student information 
	      --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
	      RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
	      --fetch into Point the cursor to the next data 
	      fetch cur_students_three into v_stu;
	   end loop;
	   --dbms_output.put_line(cur_students_three%rowcount||'');
	   RAISE NOTICE 'Number of students is:%',cur_students_three%rowcount;
	   -- Close cursor 
		   close cur_students_three;
	  else 
	  	   RAISE NOTICE 'your enter grade is error ';
		  end if;
 end



-- The cursor test obtains the student grade data 
declare
   -- A cursor variable points to the collection of second grade students in high school 
   cursor cur_to_stu is select * from students where grade = ' Senior high school grade two ';
   -- A variable is used to save a record of the cursor 
   v_stu students%rowtype;
begin
   -- Open cursor 
   open cur_to_stu;
   -- Do it once fetch into  Let the cursor point to the first data 
   fetch cur_to_stu into v_stu;
   --while loop , Conditions are cyclic conditions 
   while cur_to_stu%found loop
      -- Print student information 
      --dbms_output.put_line(v_stu.student_id ||','|| v_stu.student_name);
      RAISE NOTICE 'student id is:% ,student_name is %',v_stu.student_id,v_stu.student_name;
      --fetch into Point the cursor to the next data 
      fetch cur_to_stu into v_stu;
   end loop;
   --dbms_output.put_line(cur_to_stu%rowcount||'');
   RAISE NOTICE 'Number of students is:%',cur_to_stu%rowcount;
   -- Close cursor 
   close cur_to_stu;
end

create or replace function change_score ( p_score int, p_stu_id number,
	p_course varchar2, p_batch varchar2 ) return int as 
begin
	if p_score > 150 or p_score < 0 then 
		return 0;
	end if;
	update scores set score_value=p_score 
	where student_id =p_stu_id and course_id =p_course and batch=p_batch;
	return 1;
end;


select *  
from courses 
where course_name=' mathematics ' and category = ' Liberal arts ';

create or replace  procedure getaaa(p_stu_id number,p_batch varchar2) as 
	l_course_id varchar2;
	l_score number;
	l_grade varchar2;
	tempscore number := 0;
	l_course_name varchar2 := ' mathematics ';
begin
	select course_id  into l_course_id
	from courses 
	where course_name= ' mathematics ' and category = ' Liberal arts ';
	
	select score_value into l_score 
	from scores
	where student_id =p_stu_id and course_id = l_course_id and batch=p_batch;
		
	if l_course_name = ' English ' or l_course_name = ' mathematics ' or l_course_name = ' Chinese language and literature ' then
		tempscore =l_score/150;
	else 
	    tempscore =l_score/100;
	end if;
	
	CASE TRUE
    WHEN tempscore < 1.0 and tempscore > 0.9  
    	THEN l_grade ='A';
    WHEN tempscore < 0.9 and tempscore > 0.8  
    	THEN l_grade ='B';
    WHEN tempscore < 0.8 and tempscore > 0.7  
    	THEN l_grade ='C';
    WHEN tempscore < 0.7 and tempscore > 0.6 
    	THEN l_grade ='D';
    ELSE l_grade ='E';
  	END CASE;
  	RAISE NOTICE 'your Score grade is:% %',l_score, l_grade;
  	-- You can also use system packages ：DBMS_OUTPUT.PUT_LINE(l_grade);
 END;
---------------------plsql The module of the package is implemented separately, and the test ends -----------------------------


------------------ Simple SQL test -----------------------

-- Check the grade sheet 
select * from scores;
-- Check the curriculum 
select * from courses;
-- Check the experiment table 
select * from students;
-- Check the subject grades 
select student_name,grade,course_name,score_value,scores.batch
from  students,scores,courses
where scores.student_id = students.student_id 
and courses.course_name = ' mathematics ' 
and courses.course_id = scores.course_id
and grade =' Senior high school grade two '
order by score_value desc
limit  3;

-- Check the grades and total scores of all subjects in the specified grade 
select students.student_name,grade,course_name,score_value,sum(score_value) as total,scores.batch
from  students,scores,courses
where scores.student_id = students.student_id 
	and courses.course_id = scores.course_id
order by score_value desc;
-- Statistics results 
select student_id as  Student ID,round(avg(score_value),1) as   average ,sum(score_value) as  Total score ,max(score_value) as  The highest ,min(score_value) as  Lowest score   
from scores  
group  by student_id,batch
having  batch=' midsemester ';


-- Count the grades of the designated grades 
select *
from students,(
	select student_id as  Student ID,round(avg(score_value),1) as   average ,sum(score_value) as  Total score ,max(score_value) as  The highest ,min(score_value) as  Lowest score   
	from scores  
	group  by student_id,batch
	having  batch=' midsemester '
)
where grade = ' Senior high school grade two ' and students.student_id =  Student ID
order by  Total score  desc ;

-- Clean up the experimental environment 
drop table if exists scores;
drop table if exists courses;
drop table if exists students;
-- Test delete a student 
DELETE FROM scores WHERE student_id=1414;
DELETE FROM students WHERE student_id=1414;-- You can't just delete this , Because there are foreign keys 

------------------ Simple SQL End of test -----------------------


---------------------- Create an experiment table and its data -----------------------------
/*
--  Experimental data and its objects 
*/
-- Create student table 
CREATE TABLE students (
	student_id number(8),
	student_name char(8) not null,
	gender varchar2(2),
	age number(2),  
	grade varchar2 (40) not null,
	class varchar2 (40) not null,
	email varchar2 (30),
	sdate DATE,
	constraint pk_stuid primary key (student_id),
	constraint ch_gender check ( gender in (' male ',' Woman ')),
	constraint ch_grade check ( grade in (' First year of high school ',' Senior high school grade two ',' Third year of high school ')),
	constraint ch_age	CHECK ( age BETWEEN 12 AND 36)
);

-- Create a score sheet 
create table scores (  
	student_id number(8),  
	course_id char(2),  
	score_value number(3) default(-1),  
	batch varchar2(20)
);  

-- Create a curriculum 
create table courses  (  
	course_id char(2) primary key,  
	course_name char(20),  
	category char(20) check( category in (' Liberal arts ',' science ',' Arts and Sciences '))  
);

-- Insert student data 
INSERT INTO students VALUES(2314,' Zhang Detian ',' male ',19,' First year of high school ',' Class eight ','[email protected]',SYSDATE);
INSERT INTO students VALUES(4324,' Wu Haifeng ',' male ',18,' First year of high school ',' First class ','[email protected]',SYSDATE);
INSERT INTO students VALUES(2614,' Zhangdezheng ',' male ',20,' Senior high school grade two ',' The second shift ','[email protected]',SYSDATE);
INSERT INTO students VALUES(2184,' Song Yiran ',' Woman ',20,' Third year of high school ',' The third shift ','[email protected]',SYSDATE);
INSERT INTO students VALUES(9874,' Zhanghuale ',' Woman ',19,' Senior high school grade two ',' The second shift ','[email protected]',SYSDATE);
INSERT INTO students VALUES(1474,' Li Wenyue ',' Woman ',19,' Third year of high school ',' Class seven ','[email protected]',SYSDATE);
INSERT INTO students VALUES(6574,' auspicious ',' male ',21,' Senior high school grade two ',' Class six ','[email protected]',SYSDATE);
INSERT INTO students VALUES(8174,' Xiang Ling ',' Woman ',19,' Senior high school grade two ',' Fourth shift ','[email protected]',SYSDATE);
INSERT INTO students VALUES(1414,' Meitiantian ',' Woman ',21,' First year of high school ',' Class five ','[email protected]',SYSDATE);

-- Insert course data 
insert into courses values('01',' Chinese language and literature ',' Arts and Sciences ');
insert into courses values('06',' English ',' Arts and Sciences ');

insert into courses values('02',' mathematics ',' Liberal arts ');
insert into courses values('03',' Politics ',' Liberal arts ');
insert into courses values('04',' Geography ',' Liberal arts ');
insert into courses values('05',' history ',' Liberal arts ');

insert into courses values('07',' mathematics ',' science ');
insert into courses values('08',' biological ',' science ');
insert into courses values('09',' chemical ',' science ');
insert into courses values('10',' Physics ',' science ');

-- Insert student grades , final exam 
insert into scores values(2314,'01',110,' final exam ');
insert into scores values(4324,'01',109,' final exam ');
insert into scores values(2614,'01',88,' final exam ');
insert into scores values(2184,'01',121,' final exam ');
insert into scores values(9874,'01',114,' final exam ');
insert into scores values(1474,'01',103,' final exam ');
insert into scores values(6574,'01',113,' final exam ');
insert into scores values(8174,'01',108,' final exam ');
insert into scores values(1414,'01',125,' final exam ');

insert into scores values(2314,'02',100,' final exam ');
insert into scores values(4324,'02',104,' final exam ');
insert into scores values(2614,'02',99,' final exam ');
insert into scores values(2184,'02',101,' final exam ');
insert into scores values(9874,'02',104,' final exam ');
insert into scores values(1474,'02',113,' final exam ');
insert into scores values(6574,'02',103,' final exam ');
insert into scores values(8174,'02',118,' final exam ');
insert into scores values(1414,'02',129,' final exam ');

insert into scores values(2314,'06',101,' final exam ');
insert into scores values(4324,'06',103,' final exam ');
insert into scores values(2614,'06',127,' final exam ');
insert into scores values(2184,'06',105,' final exam ');
insert into scores values(9874,'06',101,' final exam ');
insert into scores values(1474,'06',109,' final exam ');
insert into scores values(6574,'06',100,' final exam ');
insert into scores values(8174,'06',99,' final exam ');
insert into scores values(1414,'06',114,' final exam ');

insert into scores values(2314,'03',56,' final exam ');
insert into scores values(4324,'03',75,' final exam ');
insert into scores values(2614,'03',26,' final exam ');
insert into scores values(2184,'03',76,' final exam ');
insert into scores values(9874,'03',89,' final exam ');
insert into scores values(1474,'03',90,' final exam ');
insert into scores values(6574,'03',91,' final exam ');
insert into scores values(8174,'03',57,' final exam ');
insert into scores values(1414,'03',92,' final exam ');

insert into scores values(2314,'04',76,' final exam ');
insert into scores values(4324,'04',87,' final exam ');
insert into scores values(2614,'04',56,' final exam ');
insert into scores values(2184,'04',36,' final exam ');
insert into scores values(9874,'04',84,' final exam ');
insert into scores values(1474,'04',64,' final exam ');
insert into scores values(6574,'04',82,' final exam ');
insert into scores values(8174,'04',47,' final exam ');
insert into scores values(1414,'04',66,' final exam ');

insert into scores values(2314,'05',67,' final exam ');
insert into scores values(4324,'05',83,' final exam ');
insert into scores values(2614,'05',52,' final exam ');
insert into scores values(2184,'05',26,' final exam ');
insert into scores values(9874,'05',96,' final exam ');
insert into scores values(1474,'05',91,' final exam ');
insert into scores values(6574,'05',81,' final exam ');
insert into scores values(8174,'05',87,' final exam ');
insert into scores values(1414,'05',92,' final exam ');

-- insert data , midsemester 
insert into scores values(2314,'01',110,' midsemester ');
insert into scores values(4324,'01',119,' midsemester ');
insert into scores values(2614,'01',95,' midsemester ');
insert into scores values(2184,'01',131,' midsemester ');
insert into scores values(9874,'01',145,' midsemester ');
insert into scores values(1474,'01',124,' midsemester ');
insert into scores values(6574,'01',124,' midsemester ');
insert into scores values(8174,'01',109,' midsemester ');
insert into scores values(1414,'01',121,' midsemester ');

insert into scores values(2314,'02',100,' midsemester ');
insert into scores values(4324,'02',104,' midsemester ');
insert into scores values(2614,'02',99,' midsemester ');
insert into scores values(2184,'02',101,' midsemester ');
insert into scores values(9874,'02',104,' midsemester ');
insert into scores values(1474,'02',113,' midsemester ');
insert into scores values(6574,'02',103,' midsemester ');
insert into scores values(8174,'02',118,' midsemester ');
insert into scores values(1414,'02',129,' midsemester ');

insert into scores values(2314,'06',105,' midsemester ');
insert into scores values(4324,'06',128,' midsemester ');
insert into scores values(2614,'06',126,' midsemester ');
insert into scores values(2184,'06',102,' midsemester ');
insert into scores values(9874,'06',107,' midsemester ');
insert into scores values(1474,'06',112,' midsemester ');
insert into scores values(6574,'06',102,' midsemester ');
insert into scores values(8174,'06',100,' midsemester ');
insert into scores values(1414,'06',102,' midsemester ');

insert into scores values(2314,'03',56,' midsemester ');
insert into scores values(4324,'03',77,' midsemester ');
insert into scores values(2614,'03',72,' midsemester ');
insert into scores values(2184,'03',73,' midsemester ');
insert into scores values(9874,'03',81,' midsemester ');
insert into scores values(1474,'03',82,' midsemester ');
insert into scores values(6574,'03',87,' midsemester ');
insert into scores values(8174,'03',67,' midsemester ');
insert into scores values(1414,'03',91,' midsemester ');

insert into scores values(2314,'04',78,' midsemester ');
insert into scores values(4324,'04',80,' midsemester ');
insert into scores values(2614,'04',85,' midsemester ');
insert into scores values(2184,'04',67,' midsemester ');
insert into scores values(9874,'04',85,' midsemester ');
insert into scores values(1474,'04',69,' midsemester ');
insert into scores values(6574,'04',80,' midsemester ');
insert into scores values(8174,'04',65,' midsemester ');
insert into scores values(1414,'04',69,' midsemester ');

insert into scores values(2314,'05',69,' midsemester ');
insert into scores values(4324,'05',81,' midsemester ');
insert into scores values(2614,'05',44,' midsemester ');
insert into scores values(2184,'05',56,' midsemester ');
insert into scores values(9874,'05',90,' midsemester ');
insert into scores values(1474,'05',84,' midsemester ');
insert into scores values(6574,'05',84,' midsemester ');
insert into scores values(8174,'05',76,' midsemester ');
insert into scores values(1414,'05',78,' midsemester ');
---------------------- End of creating the experiment table and its data -----------------------------