2026-03-12 20:23:15

tpt/demos/unindexed_foreign_key.sql

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+-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
+-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
+
+DROP TABLE t_child;
+DROP TABLE t_parent;
+
+CREATE TABLE t_parent(a INT PRIMARY KEY);
+CREATE TABLE t_child(b INT, c INT, FOREIGN KEY (c) REFERENCES t_parent(a));
+
+INSERT INTO t_parent SELECT rownum FROM dual CONNECT BY LEVEL<=10;
+INSERT INTO t_child SELECT rownum, MOD(rownum,9)+1 FROM dual CONNECT BY LEVEL <= 10;
+
+COMMIT;
+
+PAUSE Press enter to update CHILD table:
+
+PROMPT UPDATE t_child SET c = 10 WHERE c = 1;;
+UPDATE t_child SET c = 10 WHERE c = 1;
+
+PROMPT -- In another session run:
+PROMPT UPDATE t_parent SET a = 7 WHERE a = 6;;
+PROMPT
+