SQLite

** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
** datatype of the value
** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
** against a virtual table.
** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
** <td>&rarr;&nbsp;&nbsp;<td>True if value originated a bound parameter
** </table></blockquote>
**
** <b>Details:</b>
**
** These routines extract type, size, and content information from
** [protected sqlite3_value] objects.  Protected sqlite3_value objects
** are used to pass parameter information into implementation of

** the value for that column returned without setting a result (probably
** because it queried [sqlite3_vtab_nochange()] and found that the column
** was unchanging).  ^Within an [xUpdate] method, any value for which
** sqlite3_value_nochange(X) is true will in all other respects appear
** to be a NULL value.  If sqlite3_value_nochange(X) is invoked anywhere other
** than within an [xUpdate] method call for an UPDATE statement, then
** the return value is arbitrary and meaningless.
**
** ^The sqlite3_value_frombind(X) interface returns non-zero if the
** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
** interfaces.  ^If X comes from an SQL literal value, or a table column,
** and expression, then sqlite3_value_frombind(X) returns zero.
**
** Please pay particular attention to the fact that the pointer returned
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].
**

const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);
int sqlite3_value_nochange(sqlite3_value*);
int sqlite3_value_frombind(sqlite3_value*);

/*
** CAPI3REF: Finding The Subtype Of SQL Values
** METHOD: sqlite3_value
**
** The sqlite3_value_subtype(V) function returns the subtype for
** an [application-defined SQL function] argument V.  The subtype

static void test_getsubtype(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_result_int(context, (int)sqlite3_value_subtype(argv[0]));
}

/*         test_frombind(A,B,C,...)
**
** Return an integer bitmask that has a bit set for every argument
** (up to the first 63 arguments) that originates from a bind a parameter.
*/
static void test_frombind(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_uint64 m = 0;
  int i;
  for(i=0; i<argc && i<63; i++){
    if( sqlite3_value_frombind(argv[i]) ) m |= ((sqlite3_uint64)1)<<i;
  }
  sqlite3_result_int64(context, (sqlite3_int64)m);
}

/*         test_setsubtype(V, T)
**
** Return the value V with its subtype changed to T
*/
static void test_setsubtype(
  sqlite3_context *context,

    { "test_counter",          1, SQLITE_UTF8, counterFunc},
    { "real2hex",              1, SQLITE_UTF8, real2hex},
    { "test_decode",           1, SQLITE_UTF8, test_decode},
    { "test_extract",          2, SQLITE_UTF8, test_extract},
    { "test_zeroblob",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC, test_zeroblob},
    { "test_getsubtype",       1, SQLITE_UTF8, test_getsubtype},
    { "test_setsubtype",       2, SQLITE_UTF8, test_setsubtype},
    { "test_frombind",        -1, SQLITE_UTF8, test_frombind},
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }

  assert( pOp->p4.z==0 || pOp->p4.z==sqlite3VListNumToName(p->pVList,pOp->p1) );
  pVar = &p->aVar[pOp->p1 - 1];
  if( sqlite3VdbeMemTooBig(pVar) ){
    goto too_big;
  }
  pOut = &aMem[pOp->p2];
  sqlite3VdbeMemShallowCopy(pOut, pVar, MEM_Static);
  pOut->flags |= MEM_FromBind;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Move P1 P2 P3 * *
** Synopsis: r[P2@P3]=r[P1@P3]
**

*/
#define MEM_Null      0x0001   /* Value is NULL (or a pointer) */
#define MEM_Str       0x0002   /* Value is a string */
#define MEM_Int       0x0004   /* Value is an integer */
#define MEM_Real      0x0008   /* Value is a real number */
#define MEM_Blob      0x0010   /* Value is a BLOB */
#define MEM_AffMask   0x001f   /* Mask of affinity bits */
#define MEM_FromBind  0x0020   /* Value originates from sqlite3_bind() */
/* Available          0x0040   */
#define MEM_Undefined 0x0080   /* Value is undefined */
#define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
#define MEM_TypeMask  0xc1ff   /* Mask of type bits */


/* Whenever Mem contains a valid string or blob representation, one of

  return aType[pVal->flags&MEM_AffMask];
}

/* Return true if a parameter to xUpdate represents an unchanged column */
int sqlite3_value_nochange(sqlite3_value *pVal){
  return (pVal->flags&(MEM_Null|MEM_Zero))==(MEM_Null|MEM_Zero);
}

/* Return true if a parameter value originated from an sqlite3_bind() */
int sqlite3_value_frombind(sqlite3_value *pVal){
  return (pVal->flags&MEM_FromBind)!=0;
}

/* Make a copy of an sqlite3_value object
*/
sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){
  sqlite3_value *pNew;
  if( pOrig==0 ) return 0;
  pNew = sqlite3_malloc( sizeof(*pNew) );

}

# Test char().
#
do_execsql_test func-31.1 { 
  SELECT char(), length(char()), typeof(char()) 
} {{} 0 text}

# sqlite3_value_frombind()
#
do_execsql_test func-32.100 {
  SELECT test_frombind(1,2,3,4);
} {0}
do_execsql_test func-32.110 {
  SELECT test_frombind(1,2,?,4);
} {4}
do_execsql_test func-32.120 {
  SELECT test_frombind(1,(?),4,?+7);
} {2}
do_execsql_test func-32.130 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(a,b,c,e,f);
  INSERT INTO t1 VALUES(1,2.5,'xyz',x'e0c1b2a3',null);
  SELECT test_frombind(a,b,c,e,f,$xyz) FROM t1;
} {32}
do_execsql_test func-32.140 {
  SELECT test_frombind(a,b,c,e,f,$xyz+f) FROM t1;
} {0}
do_execsql_test func-32.150 {
  SELECT test_frombind(x.a,y.b,x.c,:123,y.e,x.f,$xyz+y.f) FROM t1 x, t1 y;
} {8}




finish_test