added ÜZ 14

Uebungszettel_14.sql

@@ -0,0 +1,59 @@
+SET SERVEROUTPUT ON;
+
+Drop table IdVal;
+
+CREATE TABLE IdVal (
+    id NUMBER GENERATED ALWAYS AS IDENTITY PRIMARY KEY ,
+    val NUMBER(3)
+);
+
+DECLARE
+    v_count NUMBER := 300;
+    v_num NUMBER := 1;
+BEGIN
+
+    FOR a IN 0..900 LOOP
+        IF a >= v_count THEN
+            v_count := v_count + 300;
+            v_num := v_num + 1;
+        END IF;
+
+        Insert into IdVal (val) values (v_num);
+    END LOOP;
+END;
+/
+
+CREATE OR REPLACE PACKAGE delete_counter
+AS
+    v_oldTable NUMBER;
+    v_newTable NUMBER;
+END delete_counter;
+/
+
+CREATE OR REPLACE TRIGGER delete_trigger_before
+BEFORE DELETE
+ON IdVal
+BEGIN
+    SELECT COUNT(*) INTO delete_counter.v_oldTable 
+    FROM IdVal; 
+END delete_trigger_before;
+/
+
+CREATE OR REPLACE TRIGGER delete_trigger_after
+AFTER DELETE
+ON IdVal
+BEGIN
+    SELECT COUNT(*) INTO delete_counter.v_newTable 
+    FROM IdVal; 
+
+    DBMS_OUTPUT.PUT_LINE('NEW: '||delete_counter.v_newTable);
+    DBMS_OUTPUT.PUT_LINE('OLD: '||delete_counter.v_oldTable);
+
+    IF delete_counter.v_newTable < (delete_counter.v_oldTable/2) THEN
+        Raise_Application_error(-20001, 'TOOO mUch DelEteED!?=');
+    END IF;
+END delete_trigger_after;
+/
+
+
+DELETE FROM IdVal WHERE ROWNUM < 500;

plfprep.sql

@@ -0,0 +1,83 @@
+Create or replace Package manage_students
+Is
+    Procedure display_student_count;
+    Procedure find_student_name
+    (i_student_id In student.id%Type,
+     o_last_name Out student.last_name%Type,
+     o_first_name Out student.first_name%Type);
+    Function id_is_good
+    (i_student_id In student.id%Type)
+    Return Boolean;
+Begin
+End manage_students;
+
+Create or replace Package Body manage_students
+Is
+    Procedure display_student_count
+    Is
+        v_count Integer;
+    Begin
+        select Count(*)
+        Into v_count
+        From student;
+        dbms(v_count);
+    End display_student_count;
+
+    Procedure find_student_name
+    (i_student_id In student.id%Type,
+     o_last_name Out student.last_name%Type,
+     o_first_name Out student.first_name%Type)
+     Is
+     Begin
+        select first_name, last_name
+        Into o_first_name, o_last_name
+        From student
+        Where i_student_id = student_id;
+     End find_student_name;
+
+    Function id_is_good
+    (i_student_id In student.id%Type)
+    Return Boolean
+    Is
+        v_count Integer;
+    Begin
+        Select Count(*)
+        Into v_count
+        From student;
+        Return Count=1;
+    Exception
+        When others Then
+            Return False;
+    End id_is_good;
+Begin
+End manage_students;
+
+Create or replace Trigger student_bi
+Before Insert on student
+For each Row
+Begin
+    -- :New.student_id := sequence_student.NextVal;
+    :New.created_By := User;
+    :New.created_Date := Sysdate;
+    if(TRUE<>manage_students.id_is_good(:New.student_id)) Then
+        Raise_Application_Error(-20000, 'Id already in Use');
+    Endif;
+End student_bi;
+Create Or replace Trigger student_ai
+After Insert On student
+Begin
+    Insert Into protocol (t_table, t_action, t_date)
+    Values('student', 'insert', Sysdate);
+End student_ai;
+
+
+Declare
+    Cursor c_students (v_student_Id student.id%type)
+    Is
+        Select * From student
+        Where student_id = v_student_Id;
+Begin
+    For v_student In c_students(1) Loop
+        dbms(v_student.first_name);
+    End Loop;
+End;