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;