SQLite

      assert( iFromCol>=0 );
      tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid";
      tFromCol.z = pFKey->pFrom->aCol[iFromCol].zName;

      tToCol.n = sqlite3Strlen30(tToCol.z);
      tFromCol.n = sqlite3Strlen30(tFromCol.z);

      /* Create the expression "OLD.zToCol = zFromCol". It is important
      ** that the "OLD.zToCol" term is on the LHS of the = operator, so
      ** that the affinity and collation sequence associated with the
      ** parent table are used for the comparison. */
      pEq = sqlite3PExpr(pParse, TK_EQ,

          sqlite3PExpr(pParse, TK_DOT, 
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld),
            sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol)
          , 0),
          sqlite3PExpr(pParse, TK_ID, 0, 0, &tFromCol)
      , 0);
      pWhere = sqlite3ExprAnd(db, pWhere, pEq);

      /* For ON UPDATE, construct the next term of the WHEN clause.
      ** The final WHEN clause will be like this:
      **
      **    WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)

  }
} {{} A {} {} B {} 3 A 2 3 B 2}

#-------------------------------------------------------------------------
# The following tests, fkey2-10.*, test "foreign key mismatch" and 
# other errors.
#
set tn 0
foreach zSql [list {
  CREATE TABLE p(a PRIMARY KEY, b);
  CREATE TABLE c(x REFERENCES p(c));
} {
  CREATE TABLE c(x REFERENCES v(y));
  CREATE VIEW v AS SELECT x AS y FROM c;
} {
  CREATE TABLE p(a, b, PRIMARY KEY(a, b));
  CREATE TABLE c(x REFERENCES p);
} {
  CREATE TABLE p(a COLLATE binary, b);
  CREATE UNIQUE INDEX i ON p(a COLLATE nocase);
  CREATE TABLE c(x REFERENCES p(a));
}] {
  drop_all_tables

  do_test fkey2-10.1.[incr tn] {
    execsql $zSql
    catchsql { INSERT INTO c DEFAULT VALUES }
  } {1 {foreign key mismatch}}
}

# "rowid" cannot be used as part of a child or parent key definition 
# unless it happens to be the name of an explicitly declared column.

} {1 {foreign key constraint failed}}
do_test fkey2-12.1.7 { 
  execsql {
    INSERT INTO t1 VALUES(2, 'two');
    COMMIT;
  }
} {}

drop_all_tables
do_test fkey2-12.2.1 {
  execsql {
    CREATE TABLE t1(x COLLATE NOCASE PRIMARY KEY);
    CREATE TRIGGER tt1 AFTER DELETE ON t1 
      WHEN EXISTS ( SELECT 1 FROM t2 WHERE old.x = y )
    BEGIN
      INSERT INTO t1 VALUES(old.x);
    END;
    CREATE TABLE t2(y REFERENCES t1);
    INSERT INTO t1 VALUES('A');
    INSERT INTO t1 VALUES('B');
    INSERT INTO t2 VALUES('a');
    INSERT INTO t2 VALUES('b');

    SELECT * FROM t1;
    SELECT * FROM t2;
  }
} {A B a b}
do_test fkey2-12.2.2 {
  execsql { DELETE FROM t1 }
  execsql {
    SELECT * FROM t1;
    SELECT * FROM t2;
  }
} {A B a b}
do_test fkey2-12.2.3 {
  execsql {
    DROP TABLE t2;
    CREATE TABLE t2(y REFERENCES t1 ON DELETE RESTRICT);
    INSERT INTO t2 VALUES('a');
    INSERT INTO t2 VALUES('b');
  }
  catchsql { DELETE FROM t1 }
} {1 {foreign key constraint failed}}
do_test fkey2-12.2.4 {
  execsql {
    SELECT * FROM t1;
    SELECT * FROM t2;
  }
} {A B a b}

#-------------------------------------------------------------------------
# The following tests, fkey2-13.*, test that FK processing is performed
# when rows are REPLACEd.
#
drop_all_tables
do_test fkey2-13.1.1 {