69 lines
1.5 KiB
SQL
69 lines
1.5 KiB
SQL
--Column ID of table A is primary key:
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CREATE TABLE A (
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ID int4 not null,
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id1 int4 not null,
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primary key (ID,ID1)
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);
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--Columns REFB of table B and REFC of C are foreign keys referenting ID of A:
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CREATE TABLE B (
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REFB int4,
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REFB1 INT4
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);
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CREATE INDEX BI ON B (REFB);
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CREATE TABLE C (
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REFC int4,
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REFC1 int4
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);
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CREATE INDEX CI ON C (REFC);
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--Trigger for table A:
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CREATE TRIGGER AT BEFORE DELETE ON A FOR EACH ROW
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EXECUTE PROCEDURE
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check_foreign_key (2, 'cascade', 'ID','id1', 'B', 'REFB','REFB1', 'C', 'REFC','REFC1');
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CREATE TRIGGER AT1 AFTER UPDATE ON A FOR EACH ROW
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EXECUTE PROCEDURE
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check_foreign_key (2, 'cascade', 'ID','id1', 'B', 'REFB','REFB1', 'C', 'REFC','REFC1');
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CREATE TRIGGER BT BEFORE INSERT OR UPDATE ON B FOR EACH ROW
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EXECUTE PROCEDURE
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check_primary_key ('REFB','REFB1', 'A', 'ID','ID1');
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CREATE TRIGGER CT BEFORE INSERT OR UPDATE ON C FOR EACH ROW
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EXECUTE PROCEDURE
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check_primary_key ('REFC','REFC1', 'A', 'ID','ID1');
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-- Now try
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INSERT INTO A VALUES (10,10);
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INSERT INTO A VALUES (20,20);
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INSERT INTO A VALUES (30,30);
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INSERT INTO A VALUES (40,41);
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INSERT INTO A VALUES (50,50);
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INSERT INTO B VALUES (1); -- invalid reference
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INSERT INTO B VALUES (10,10);
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INSERT INTO B VALUES (30,30);
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INSERT INTO B VALUES (30,30);
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INSERT INTO C VALUES (11); -- invalid reference
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INSERT INTO C VALUES (20,20);
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INSERT INTO C VALUES (20,21);
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INSERT INTO C VALUES (30,30);
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-- now update work well
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update A set ID = 100 , ID1 = 199 where ID=30 ;
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SELECT * FROM A;
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SELECT * FROM B;
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SELECT * FROM C;
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