SQLite

    HashElem *k;           /* Loop counter:  Next table in schema */
    int x;                 /* result variable */
    int regResult;         /* 3 registers to hold a result row */
    int regKey;            /* Register to hold key for checking the FK */
    int regRow;            /* Registers to hold a row from pTab */
    int addrTop;           /* Top of a loop checking foreign keys */
    int addrOk;            /* Jump here if the key is OK */
    int *aiCols;           /* child to parent column mapping */

    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    regResult = pParse->nMem+1;
    pParse->nMem += 4;
    regKey = ++pParse->nMem;
    regRow = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);

      if( pFK ) break;
      if( pParse->nTab<i ) pParse->nTab = i;
      addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0);
      for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
        pParent = sqlite3LocateTable(pParse, 0, pFK->zTo, zDb);
        assert( pParent!=0 );
        pIdx = 0;
        aiCols = 0;
        x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
        assert( x==0 );
        addrOk = sqlite3VdbeMakeLabel(v);
        if( pIdx==0 ){
          int iKey = pFK->aCol[0].iFrom;
          if( iKey>=0 && iKey!=pTab->iPKey ){
            sqlite3VdbeAddOp3(v, OP_Column, 0, iKey, regRow);
            sqlite3ColumnDefault(v, pTab, iKey, regRow);
            sqlite3VdbeAddOp2(v, OP_IsNull, regRow, addrOk);
            sqlite3VdbeAddOp2(v, OP_MustBeInt, regRow,
               sqlite3VdbeCurrentAddr(v)+3);
          }else{
            sqlite3VdbeAddOp2(v, OP_Rowid, 0, regRow);
          }
          sqlite3VdbeAddOp3(v, OP_NotExists, i, 0, regRow);
          sqlite3VdbeAddOp2(v, OP_Goto, 0, addrOk);
          sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
        }else{
          for(j=0; j<pFK->nCol; j++){
            sqlite3ExprCodeGetColumnOfTable(v, pTab, 0,
                            aiCols ? aiCols[j] : pFK->aCol[0].iFrom, regRow+j);
            sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk);
          }
          sqlite3VdbeAddOp3(v, OP_MakeRecord, regRow, pFK->nCol, regKey);
          sqlite3VdbeChangeP4(v, -1,
                   sqlite3IndexAffinityStr(v,pIdx), P4_TRANSIENT);
          sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
        }
        sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
        sqlite3VdbeAddOp4(v, OP_String8, 0, regResult+2, 0, 
                          pFK->zTo, P4_TRANSIENT);
        sqlite3VdbeAddOp2(v, OP_Integer, i-1, regResult+3);
        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
        sqlite3VdbeResolveLabel(v, addrOk);
        sqlite3DbFree(db, aiCols);
      }
      sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1);
      sqlite3VdbeJumpHere(v, addrTop);
    }
  }else
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */

# 2012 December 17
#
# 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.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file tests the PRAGMA foreign_key_check command.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable {!foreignkey} {
  finish_test
  return
}

do_test fkey5-1.1 {
  db eval {
    CREATE TABLE p1(a INTEGER PRIMARY KEY); INSERT INTO p1 VALUES(88),(89);
    CREATE TABLE p2(a INT PRIMARY KEY); INSERT INTO p2 VALUES(77),(78);
    CREATE TABLE p3(a TEXT PRIMARY KEY);
    INSERT INTO p3 VALUES(66),(67),('alpha'),('BRAVO');
    CREATE TABLE p4(a TEXT PRIMARY KEY COLLATE nocase);
    INSERT INTO p4 VALUES('alpha'),('BRAVO'),('55'),('Delta'),('ECHO');
    CREATE TABLE p5(a INTEGER PRIMARY KEY, b, c, UNIQUE(b,c));
    INSERT INTO p5 VALUES(1,'Alpha','abc'),(2,'beta','def');
    CREATE TABLE p6(a INTEGER PRIMARY KEY, b TEXT COLLATE nocase,
                    c TEXT COLLATE rtrim, UNIQUE(b,c));
    INSERT INTO p6 VALUES(1,'Alpha','abc '),(2,'bETA','def    ');

    CREATE TABLE c1(x INTEGER PRIMARY KEY references p1);
    CREATE TABLE c2(x INTEGER PRIMARY KEY references p2);
    CREATE TABLE c3(x INTEGER PRIMARY KEY references p3);
    CREATE TABLE c4(x INTEGER PRIMARY KEY references p4);
    CREATE TABLE c5(x INT references p1);
    CREATE TABLE c6(x INT references p2);
    CREATE TABLE c7(x INT references p3);
    CREATE TABLE c8(x INT references p4);
    CREATE TABLE c9(x TEXT UNIQUE references p1);
    CREATE TABLE c10(x TEXT UNIQUE references p2);
    CREATE TABLE c11(x TEXT UNIQUE references p3);
    CREATE TABLE c12(x TEXT UNIQUE references p4);
    CREATE TABLE c13(x TEXT COLLATE nocase references p3);
    CREATE TABLE c14(x TEXT COLLATE nocase references p4);
    CREATE TABLE c15(x, y, FOREIGN KEY(x,y) REFERENCES p5(b,c));
    CREATE TABLE c16(x, y, FOREIGN KEY(x,y) REFERENCES p5(c,b));
    CREATE TABLE c17(x, y, FOREIGN KEY(x,y) REFERENCES p6(b,c));
    CREATE TABLE c18(x, y, FOREIGN KEY(x,y) REFERENCES p6(c,b));
    CREATE TABLE c19(x TEXT COLLATE nocase, y TEXT COLLATE rtrim,
                     FOREIGN KEY(x,y) REFERENCES p5(b,c));
    CREATE TABLE c20(x TEXT COLLATE nocase, y TEXT COLLATE rtrim,
                     FOREIGN KEY(x,y) REFERENCES p5(c,b));
    CREATE TABLE c21(x TEXT COLLATE nocase, y TEXT COLLATE rtrim,
                     FOREIGN KEY(x,y) REFERENCES p6(b,c));
    CREATE TABLE c22(x TEXT COLLATE nocase, y TEXT COLLATE rtrim,
                     FOREIGN KEY(x,y) REFERENCES p6(c,b));

    PRAGMA foreign_key_check;
  }
} {}    
do_test fkey5-1.2 {
  db eval {
    INSERT INTO c1 VALUES(90),(87),(88);
    PRAGMA foreign_key_check;
  }
} {c1 87 p1 0 c1 90 p1 0}
do_test fkey5-1.3 {
  db eval {
    PRAGMA foreign_key_check(c1);
  }
} {c1 87 p1 0 c1 90 p1 0}
do_test fkey5-1.4 {
  db eval {
    PRAGMA foreign_key_check(c2);
  }
} {}

do_test fkey5-2.0 {
  db eval {
    INSERT INTO c5 SELECT x FROM c1;
    DELETE FROM c1;
    PRAGMA foreign_key_check;
  }
} {c5 1 p1 0 c5 3 p1 0}
do_test fkey5-2.1 {
  db eval {
    PRAGMA foreign_key_check(c5);
  }
} {c5 1 p1 0 c5 3 p1 0}
do_test fkey5-2.2 {
  db eval {
    PRAGMA foreign_key_check(c1);
  }
} {}

do_test fkey5-3.0 {
  db eval {
    INSERT INTO c9 SELECT x FROM c5;
    DELETE FROM c5;
    PRAGMA foreign_key_check;
  }
} {c9 1 p1 0 c9 3 p1 0}
do_test fkey5-3.1 {
  db eval {
    PRAGMA foreign_key_check(c9);
  }
} {c9 1 p1 0 c9 3 p1 0}
do_test fkey5-3.2 {
  db eval {
    PRAGMA foreign_key_check(c5);
  }
} {}

do_test fkey5-4.0 {
  db eval {
    DELETE FROM c9;
    INSERT INTO c2 VALUES(79),(77),(76);
    PRAGMA foreign_key_check;
  }
} {c2 76 p2 0 c2 79 p2 0}
do_test fkey5-4.1 {
  db eval {
    PRAGMA foreign_key_check(c2);
  }
} {c2 76 p2 0 c2 79 p2 0}
do_test fkey5-4.2 {
  db eval {
    INSERT INTO c6 SELECT x FROM c2;
    DELETE FROM c2;
    PRAGMA foreign_key_check;
  }
} {c6 1 p2 0 c6 3 p2 0}
do_test fkey5-4.3 {
  db eval {
    PRAGMA foreign_key_check(c6);
  }
} {c6 1 p2 0 c6 3 p2 0}
do_test fkey5-4.4 {
  db eval {
    INSERT INTO c10 SELECT x FROM c6;
    DELETE FROM c6;
    PRAGMA foreign_key_check;
  }
} {c10 1 p2 0 c10 3 p2 0}
do_test fkey5-4.5 {
  db eval {
    PRAGMA foreign_key_check(c10);
  }
} {c10 1 p2 0 c10 3 p2 0}

do_test fkey5-5.0 {
  db eval {
    DELETE FROM c10;
    INSERT INTO c3 VALUES(68),(67),(65);
    PRAGMA foreign_key_check;
  }
} {c3 65 p3 0 c3 68 p3 0}
do_test fkey5-5.1 {
  db eval {
    PRAGMA foreign_key_check(c3);
  }
} {c3 65 p3 0 c3 68 p3 0}
do_test fkey5-5.2 {
  db eval {
    INSERT INTO c7 SELECT x FROM c3;
    INSERT INTO c7 VALUES('Alpha'),('alpha'),('foxtrot');
    DELETE FROM c3;
    PRAGMA foreign_key_check;
  }
} {c7 1 p3 0 c7 3 p3 0 c7 4 p3 0 c7 6 p3 0}
do_test fkey5-5.3 {
  db eval {
    PRAGMA foreign_key_check(c7);
  }
} {c7 1 p3 0 c7 3 p3 0 c7 4 p3 0 c7 6 p3 0}
do_test fkey5-5.4 {
  db eval {
    INSERT INTO c11 SELECT x FROM c7;
    DELETE FROM c7;
    PRAGMA foreign_key_check;
  }
} {c11 1 p3 0 c11 3 p3 0 c11 4 p3 0 c11 6 p3 0}
do_test fkey5-5.5 {
  db eval {
    PRAGMA foreign_key_check(c11);
  }
} {c11 1 p3 0 c11 3 p3 0 c11 4 p3 0 c11 6 p3 0}

do_test fkey5-6.0 {
  db eval {
    DELETE FROM c11;
    INSERT INTO c4 VALUES(54),(55),(56);
    PRAGMA foreign_key_check;
  }
} {c4 54 p4 0 c4 56 p4 0}
do_test fkey5-6.1 {
  db eval {
    PRAGMA foreign_key_check(c4);
  }
} {c4 54 p4 0 c4 56 p4 0}
do_test fkey5-6.2 {
  db eval {
    INSERT INTO c8 SELECT x FROM c4;
    INSERT INTO c8 VALUES('Alpha'),('ALPHA'),('foxtrot');
    DELETE FROM c4;
    PRAGMA foreign_key_check;
  }
} {c8 1 p4 0 c8 3 p4 0 c8 6 p4 0}
do_test fkey5-6.3 {
  db eval {
    PRAGMA foreign_key_check(c8);
  }
} {c8 1 p4 0 c8 3 p4 0 c8 6 p4 0}
do_test fkey5-6.4 {
  db eval {
    INSERT INTO c12 SELECT x FROM c8;
    DELETE FROM c8;
    PRAGMA foreign_key_check;
  }
} {c12 1 p4 0 c12 3 p4 0 c12 6 p4 0}
do_test fkey5-6.5 {
  db eval {
    PRAGMA foreign_key_check(c12);
  }
} {c12 1 p4 0 c12 3 p4 0 c12 6 p4 0}

do_test fkey5-7.1 {
  db eval {
    INSERT OR IGNORE INTO c13 SELECT * FROM c12;
    INSERT OR IGNORE INTO C14 SELECT * FROM c12;
    DELETE FROM c12;
    PRAGMA foreign_key_check;
  }
} {c14 1 p4 0 c14 3 p4 0 c14 6 p4 0 c13 1 p3 0 c13 2 p3 0 c13 3 p3 0 c13 4 p3 0 c13 5 p3 0 c13 6 p3 0}
do_test fkey5-7.2 {
  db eval {
    PRAGMA foreign_key_check(c14);
  }
} {c14 1 p4 0 c14 3 p4 0 c14 6 p4 0}
do_test fkey5-7.3 {
  db eval {
    PRAGMA foreign_key_check(c13);
  }
} {c13 1 p3 0 c13 2 p3 0 c13 3 p3 0 c13 4 p3 0 c13 5 p3 0 c13 6 p3 0}

do_test fkey5-8.0 {
  db eval {
    DELETE FROM c13;
    DELETE FROM c14;
    INSERT INTO c19 VALUES('alpha','abc');
    PRAGMA foreign_key_check(c19);
  }
} {c19 1 p5 0}
do_test fkey5-8.1 {
  db eval {
    DELETE FROM c19;
    INSERT INTO c19 VALUES('Alpha','abc');
    PRAGMA foreign_key_check(c19);
  }
} {}
do_test fkey5-8.2 {
  db eval {
    INSERT INTO c20 VALUES('Alpha','abc');
    PRAGMA foreign_key_check(c20);
  }
} {c20 1 p5 0}
do_test fkey5-8.3 {
  db eval {
    DELETE FROM c20;
    INSERT INTO c20 VALUES('abc','Alpha');
    PRAGMA foreign_key_check(c20);
  }
} {}
do_test fkey5-8.4 {
  db eval {
    INSERT INTO c21 VALUES('alpha','abc    ');
    PRAGMA foreign_key_check(c21);
  }
} {}
do_test fkey5-8.5 {
  db eval {
    DELETE FROM c21;
    INSERT INTO c19 VALUES('Alpha','abc');
    PRAGMA foreign_key_check(c21);
  }
} {}
do_test fkey5-8.6 {
  db eval {
    INSERT INTO c22 VALUES('Alpha','abc');
    PRAGMA foreign_key_check(c22);
  }
} {c22 1 p6 0}
do_test fkey5-8.7 {
  db eval {
    DELETE FROM c22;
    INSERT INTO c22 VALUES('abc  ','ALPHA');
    PRAGMA foreign_key_check(c22);
  }
} {}



finish_test