sqlite/test/conflict4.test

# 2026-07-20
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Test cases for UNIQUE ON CONFLICT REPLACE and UNIQUE ON CONFLICT FAIL
# behavior including when there are also triggers and/or an UPSERT.
#
# Forum thread 2026-07-17T09:30:42Z
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix conflict4

# Combination of ON CONFLICT FAIL on a UNIQUE index and
# an ON CONFLICT DO NOTHING in a different index leads to
# database corruption.
#
do_execsql_test 1.1 {
  CREATE TABLE t0(
    a INTEGER PRIMARY KEY ON CONFLICT REPLACE,
    b INT UNIQUE          ON CONFLICT FAIL,
    c INT UNIQUE          ON CONFLICT ABORT
  );
  INSERT INTO t0 VALUES (1, 10, 100),(2, 20, 200);
}
do_catchsql_test 1.2 {
  INSERT INTO t0 VALUES (1, 20, 300) ON CONFLICT(c) DO NOTHING;
} {1 {UNIQUE constraint failed: t0.b}}
do_execsql_test 1.3 {
  PRAGMA integrity_check;
} {ok}
do_execsql_test 1.4 {
  SELECT * FROM t0 ORDER BY a;
} {1 10 100 2 20 200}
do_execsql_test 1.5 {
  DROP TABLE t0;
  CREATE TABLE t0(
    a INTEGER PRIMARY KEY ON CONFLICT REPLACE,
    b INT UNIQUE          ON CONFLICT IGNORE,
    c INT UNIQUE          ON CONFLICT ABORT
  );
  INSERT INTO t0 VALUES (1, 10, 100),(2, 20, 200);
}
do_catchsql_test 1.6 {
  INSERT INTO t0 VALUES (1, 20, 300) ON CONFLICT(c) DO NOTHING;
} {0 {}}
do_execsql_test 1.7 {
  PRAGMA integrity_check;
} {ok}
do_execsql_test 1.8 {
  SELECT * FROM t0 ORDER BY a;
} {1 10 100 2 20 200}
do_execsql_test 1.9 {
  DROP TABLE t0;
  CREATE TABLE t0(
    a INTEGER PRIMARY KEY ON CONFLICT REPLACE,
    b INT UNIQUE          ON CONFLICT FAIL,
    c INT UNIQUE          ON CONFLICT ABORT
  );
  INSERT INTO t0 VALUES (1, 10, 100),(2, 20, 200);
}
do_catchsql_test 1.10 {
  INSERT INTO t0 VALUES (1, 20, 300) ON CONFLICT(c) DO NOTHING;
} {1 {UNIQUE constraint failed: t0.b}}
do_execsql_test 1.11 {
  PRAGMA integrity_check;
} {ok}
do_execsql_test 1.12 {
  SELECT * FROM t0 ORDER BY a;
} {1 10 100 2 20 200}
do_execsql_test 1.13 {
  DROP TABLE t0;
  CREATE TABLE t1(
    a INTEGER PRIMARY KEY,
    b UNIQUE ON CONFLICT FAIL,
    c UNIQUE
  );
  INSERT INTO t1 VALUES(1, 1, 1);
}
do_catchsql_test 1.14 {
  -- Inserts 0 rows, because hitting the constraint on (b) does ABORT:
  INSERT INTO t1 VALUES(3, 3, 3), (2, 1, 2) ON CONFLICT(c) DO NOTHING;
} {1 {UNIQUE constraint failed: t1.b}}
do_execsql_test 1.15 {
  SELECT * FROM t1 ORDER BY a;
} {1 1 1 3 3 3}
do_catchsql_test 1.16 {
  -- Inserts 1 row, because hitting the constraint on (b) does FAIL:
  DELETE FROM t1 WHERE a=3;
  INSERT INTO t1 VALUES(3, 3, 3), (2, 1, 2);
} {1 {UNIQUE constraint failed: t1.b}}
do_execsql_test 1.17 {
  SELECT * FROM t1 ORDER BY a;
} {1 1 1 3 3 3}
do_execsql_test 1.18 {
  PRAGMA integrity_check;
} ok

# Counter-example to the fix at check-in 2026-07-17T16:26:56.257Z
# provided by Pavan Nambi at forum post 2026-07-18T03:35:48Z
do_execsql_test 2.1 {
  DROP TABLE t1;
  PRAGMA recursive_triggers=ON;
  CREATE TABLE t2(
    a INTEGER PRIMARY KEY ON CONFLICT REPLACE,
    b INT UNIQUE          ON CONFLICT FAIL,
    c INT UNIQUE          ON CONFLICT ABORT
  );
  CREATE TRIGGER t_ad AFTER DELETE ON t2 BEGIN
    INSERT INTO t2 VALUES(99,30,999);
  END;
  INSERT INTO t2 VALUES(1,10,100),(2,20,200);
  SELECT * FROM t2 ORDER BY a;
} {1 10 100 2 20 200}
do_catchsql_test 2.2 {
  INSERT INTO t2 VALUES(4,40,400),(1,30,300),(5,50,500)
      ON CONFLICT(c) DO NOTHING;
} {1 {UNIQUE constraint failed: t2.b}}
do_execsql_test 2.3 {
  PRAGMA integrity_check;
} ok
do_execsql_test 2.4 {
  SELECT * FROM t2 ORDER BY a;
} {1 10 100 2 20 200}

# This is a slightly simpler version of the test above.  Before
# the bug was fixed, this would:
#
#   1) Checks there are no instances of 'HELLO' in the index on t1(b),
#   2) Deletes the row from t1 as a result of the REPLACE on the PK,
#   3) Fires the trigger, inserting ('HELLO', 200) into index t1(b).
#   4) Finishes the insert without rechecking t1(b), inserting 
#      ('HELLO', 100). Corruption.
#
reset_db
do_execsql_test 3.1 {
  PRAGMA recursive_triggers = ON;
  CREATE TABLE t1(
      a PRIMARY KEY ON CONFLICT REPLACE,
      b UNIQUE
  );
  INSERT INTO t1 VALUES(100, 'abcde');
  CREATE TRIGGER tr1 AFTER DELETE ON t1 BEGIN
    INSERT INTO t1 VALUES(200, 'HELLO');
  END;
}
do_catchsql_test 3.2 {
  INSERT INTO t1 VALUES(100, 'HELLO');
} {1 {UNIQUE constraint failed: t1.b}}
do_execsql_test 3.3 {
  PRAGMA integrity_check;
  SELECT * FROM t1 ORDER BY +a;
} {ok 100 abcde}

finish_test