SQLite

** Erase the given database page and all its children.  Return
** the page to the freelist.
*/
static int clearDatabasePage(
  BtShared *pBt,           /* The BTree that contains the table */
  Pgno pgno,               /* Page number to clear */
  int freePageFlag,        /* Deallocate page if true */
  i64 *pnChange            /* Add number of Cells freed to this counter */
){
  MemPage *pPage;
  int rc;
  unsigned char *pCell;
  int i;
  int hdr;
  CellInfo info;

** This routine will fail with SQLITE_LOCKED if there are any open
** read cursors on the table.  Open write cursors are moved to the
** root of the table.
**
** If pnChange is not NULL, then the integer value pointed to by pnChange
** is incremented by the number of entries in the table.
*/
int sqlite3BtreeClearTable(Btree *p, int iTable, i64 *pnChange){
  int rc;
  BtShared *pBt = p->pBt;
  sqlite3BtreeEnter(p);
  assert( p->inTrans==TRANS_WRITE );

  rc = saveAllCursors(pBt, (Pgno)iTable, 0);

** anywhere - the key is the content.  (BTREE_BLOBKEY is used for SQL
** indices.)
*/
#define BTREE_INTKEY     1    /* Table has only 64-bit signed integer keys */
#define BTREE_BLOBKEY    2    /* Table has keys only - no data */

int sqlite3BtreeDropTable(Btree*, int, int*);
int sqlite3BtreeClearTable(Btree*, int, i64*);
int sqlite3BtreeClearTableOfCursor(BtCursor*);
int sqlite3BtreeTripAllCursors(Btree*, int, int);

void sqlite3BtreeGetMeta(Btree *pBtree, int idx, u32 *pValue);
int sqlite3BtreeUpdateMeta(Btree*, int idx, u32 value);

int sqlite3BtreeNewDb(Btree *p);

static void changes(
  sqlite3_context *context,
  int NotUsed,
  sqlite3_value **NotUsed2
){
  sqlite3 *db = sqlite3_context_db_handle(context);
  UNUSED_PARAMETER2(NotUsed, NotUsed2);
  sqlite3_result_int64(context, sqlite3_changes64(db));
}

/*
** Implementation of the total_changes() SQL function.  The return value is
** the same as the sqlite3_total_changes() API function.
*/
static void total_changes(

  db->lastRowid = iRowid;
  sqlite3_mutex_leave(db->mutex);
}

/*
** Return the number of changes in the most recent call to sqlite3_exec().
*/
sqlite3_int64 sqlite3_changes64(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nChange;
}
int sqlite3_changes(sqlite3 *db){
  return (int)sqlite3_changes64(db);
}

/*
** Return the number of changes since the database handle was opened.
*/
sqlite3_int64 sqlite3_total_changes64(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nTotalChange;
}
int sqlite3_total_changes(sqlite3 *db){
  return (int)sqlite3_total_changes64(db);
}

/*
** Close all open savepoints. This function only manipulates fields of the
** database handle object, it does not close any savepoints that may be open
** at the b-tree/pager level.
*/
void sqlite3CloseSavepoints(sqlite3 *db){

*/
void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);

/*
** CAPI3REF: Count The Number Of Rows Modified
** METHOD: sqlite3
**
** ^These functions return the number of rows modified, inserted or
** deleted by the most recently completed INSERT, UPDATE or DELETE
** statement on the database connection specified by the only parameter.
** The two functions are identical except for the type of the return value
** and that if the number of rows modified by the most recent INSERT, UPDATE 
** or DELETE is greater than the maximum value supported by type "int", then
** the return value of sqlite3_changes() is undefined. ^Executing any other
** type of SQL statement does not modify the value returned by these functions.

**
** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 
** [foreign key actions] or [REPLACE] constraint resolution are not counted.
** 
** Changes to a view that are intercepted by 
** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 

** <li> the [sqlite3_total_changes()] interface
** <li> the [count_changes pragma]
** <li> the [changes() SQL function]
** <li> the [data_version pragma]
** </ul>
*/
int sqlite3_changes(sqlite3*);
sqlite3_int64 sqlite3_changes64(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified
** METHOD: sqlite3
**
** ^These functions return the total number of rows inserted, modified or
** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
** since the database connection was opened, including those executed as
** part of trigger programs. The two functions are identical except for the 
** type of the return value and that if the number of rows modified by the 
** connection exceeds the maximum value supported by type "int", then
** the return value of sqlite3_total_changes() is undefined. ^Executing 
** any other type of SQL statement does not affect the value returned by 
** sqlite3_total_changes().
** 
** ^Changes made as part of [foreign key actions] are included in the
** count, but those made as part of REPLACE constraint resolution are
** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 
** are not counted.
**
** The [sqlite3_total_changes(D)] interface only reports the number

** <li> the [count_changes pragma]
** <li> the [changes() SQL function]
** <li> the [data_version pragma]
** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
** </ul>
*/
int sqlite3_total_changes(sqlite3*);
sqlite3_int64 sqlite3_total_changes64(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query
** METHOD: sqlite3
**
** ^This function causes any pending database operation to abort and
** return at its earliest opportunity. This routine is typically

  u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
  u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
  u8 mTrace;                    /* zero or more SQLITE_TRACE flags */
  u8 noSharedCache;             /* True if no shared-cache backends */
  u8 nSqlExec;                  /* Number of pending OP_SqlExec opcodes */
  int nextPagesize;             /* Pagesize after VACUUM if >0 */
  u32 magic;                    /* Magic number for detect library misuse */
  i64 nChange;                  /* Value returned by sqlite3_changes() */
  i64 nTotalChange;             /* Value returned by sqlite3_total_changes() */
  int aLimit[SQLITE_N_LIMIT];   /* Limits */
  int nMaxSorterMmap;           /* Maximum size of regions mapped by sorter */
  struct sqlite3InitInfo {      /* Information used during initialization */
    Pgno newTnum;               /* Rootpage of table being initialized */
    u8 iDb;                     /* Which db file is being initialized */
    u8 busy;                    /* TRUE if currently initializing */
    unsigned orphanTrigger : 1; /* Last statement is orphaned TEMP trigger */

Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
Expr *sqlite3ExprSkipCollate(Expr*);
Expr *sqlite3ExprSkipCollateAndLikely(Expr*);
int sqlite3CheckCollSeq(Parse *, CollSeq *);
int sqlite3WritableSchema(sqlite3*);
int sqlite3CheckObjectName(Parse*, const char*,const char*,const char*);
void sqlite3VdbeSetChanges(sqlite3 *, i64);
int sqlite3AddInt64(i64*,i64);
int sqlite3SubInt64(i64*,i64);
int sqlite3MulInt64(i64*,i64);
int sqlite3AbsInt32(int);
#ifdef SQLITE_ENABLE_8_3_NAMES
void sqlite3FileSuffix3(const char*, char*);
#else

  case DB_CHANGES: {
    Tcl_Obj *pResult;
    if( objc!=2 ){
      Tcl_WrongNumArgs(interp, 2, objv, "");
      return TCL_ERROR;
    }
    pResult = Tcl_GetObjResult(interp);
    Tcl_SetWideIntObj(pResult, sqlite3_changes64(pDb->db));
    break;
  }

  /*    $db close
  **
  ** Shutdown the database
  */

  case DB_TOTAL_CHANGES: {
    Tcl_Obj *pResult;
    if( objc!=2 ){
      Tcl_WrongNumArgs(interp, 2, objv, "");
      return TCL_ERROR;
    }
    pResult = Tcl_GetObjResult(interp);
    Tcl_SetWideIntObj(pResult, sqlite3_total_changes64(pDb->db));
    break;
  }

  /*    $db trace ?CALLBACK?
  **
  ** Make arrangements to invoke the CALLBACK routine for each SQL statement
  ** that is executed.  The text of the SQL is appended to CALLBACK before

  sqlite3_value *pOut     /* Write results here, if not NULL. VACUUM INTO */
){
  int rc = SQLITE_OK;     /* Return code from service routines */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;           /* The temporary database we vacuum into */
  u32 saved_mDbFlags;     /* Saved value of db->mDbFlags */
  u64 saved_flags;        /* Saved value of db->flags */
  i64 saved_nChange;      /* Saved value of db->nChange */
  i64 saved_nTotalChange; /* Saved value of db->nTotalChange */
  u32 saved_openFlags;    /* Saved value of db->openFlags */
  u8 saved_mTrace;        /* Saved trace settings */
  Db *pDb = 0;            /* Database to detach at end of vacuum */
  int isMemDb;            /* True if vacuuming a :memory: database */
  int nRes;               /* Bytes of reserved space at the end of each page */
  int nDb;                /* Number of attached databases */
  const char *zDbMain;    /* Schema name of database to vacuum */

** by the number of rows in the table being cleared. If P3 is greater
** than zero, then the value stored in register P3 is also incremented
** by the number of rows in the table being cleared.
**
** See also: Destroy
*/
case OP_Clear: {
  i64 nChange;
 
  sqlite3VdbeIncrWriteCounter(p, 0);
  nChange = 0;
  assert( p->readOnly==0 );
  assert( DbMaskTest(p->btreeMask, pOp->p2) );
  rc = sqlite3BtreeClearTable(db->aDb[pOp->p2].pBt, (u32)pOp->p1, &nChange);
  if( pOp->p3 ){

#endif
  int nCursor;            /* Number of entries in apCsr */
  int pc;                 /* Program Counter in parent (calling) frame */
  int nOp;                /* Size of aOp array */
  int nMem;               /* Number of entries in aMem */
  int nChildMem;          /* Number of memory cells for child frame */
  int nChildCsr;          /* Number of cursors for child frame */
  i64 nChange;            /* Statement changes (Vdbe.nChange)     */
  i64 nDbChange;          /* Value of db->nChange */
};

/* Magic number for sanity checking on VdbeFrame objects */
#define SQLITE_FRAME_MAGIC 0x879fb71e

/*
** Return a pointer to the array of registers allocated for use

  ynVar nVar;             /* Number of entries in aVar[] */
  u32 iVdbeMagic;         /* Magic number defining state of the SQL statement */
  int nMem;               /* Number of memory locations currently allocated */
  int nCursor;            /* Number of slots in apCsr[] */
  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
  i64 nChange;            /* Number of db changes made since last reset */
  int iStatement;         /* Statement number (or 0 if has no opened stmt) */
  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  Mem *aMem;              /* The memory locations */
  Mem **apArg;            /* Arguments to currently executing user function */

  return SQLITE_OK;
}

/*
** This routine sets the value to be returned by subsequent calls to
** sqlite3_changes() on the database handle 'db'. 
*/
void sqlite3VdbeSetChanges(sqlite3 *db, i64 nChange){
  assert( sqlite3_mutex_held(db->mutex) );
  db->nChange = nChange;
  db->nTotalChange += nChange;
}

/*
** Set a flag in the vdbe to update the change counter when it is finalised

# Tests for the sqlite3_changes() and sqlite3_total_changes() APIs.
#

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

# To test that the change-counters do not suffer from 32-bit signed integer 
# rollover, add the following line to the array of test cases below. The
# test will take will over an hour to run.
#
#   7 (1<<31)+10 ""
#

foreach {tn nRow wor} {
  1 50 ""
  2 50 "WITHOUT ROWID"

  3 5000 ""
  4 5000 "WITHOUT ROWID"