SQLite

  Parse *pParse,  /* Parsing context */
  Table *pTab,    /* The table containing the value */
  int iTabCur,    /* The table cursor.  Or the PK cursor for WITHOUT ROWID */
  int iCol,       /* Index of the column to extract */
  int regOut      /* Extract the value into this register */
){
  Vdbe *v = pParse->pVdbe;
  Column *pCol;
  assert( v!=0 );
  if( pTab==0 ){
    sqlite3VdbeAddOp3(v, OP_Column, iTabCur, iCol, regOut);
    return;
  }
  if( iCol<0 || iCol==pTab->iPKey ){
    sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
  }else{
    int op;
    int x;
    if( IsVirtual(pTab) ){
      op = OP_VColumn;
      x = iCol;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    }else if( (pCol = &pTab->aCol[iCol])->colFlags & COLFLAG_VIRTUAL ){
      if( pCol->colFlags & COLFLAG_BUSY ){
        sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pCol->zName);
      }else{
        int savedSelfTab = pParse->iSelfTab;
        pCol->colFlags |= COLFLAG_BUSY;
        pParse->iSelfTab = iTabCur+1;
        sqlite3ExprCode(pParse, pTab->aCol[iCol].pDflt, regOut);
        pParse->iSelfTab = savedSelfTab;
        pCol->colFlags &= ~COLFLAG_BUSY;
      }
      return;
#endif
    }else if( !HasRowid(pTab) ){
      x = sqlite3ColumnOfIndex(sqlite3PrimaryKeyIndex(pTab), iCol);
      op = OP_Column;
    }else{
      x = sqlite3ColumnOfTable(pTab,iCol);

**  'A'            BLOB
**  'B'            TEXT
**  'C'            NUMERIC
**  'D'            INTEGER
**  'E'            REAL
*/
void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
  int i, j;
  char *zColAff = pTab->zColAff;
  if( zColAff==0 ){
    sqlite3 *db = sqlite3VdbeDb(v);
    zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
    if( !zColAff ){
      sqlite3OomFault(db);
      return;
    }

    for(i=j=0; i<pTab->nCol; i++){
      assert( pTab->aCol[i].affinity!=0 );
      if( (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
        zColAff[j++] = pTab->aCol[i].affinity;
      }
    }
    do{
      zColAff[j--] = 0;
    }while( j>=0 && zColAff[j]<=SQLITE_AFF_BLOB );
    pTab->zColAff = zColAff;
  }
  assert( zColAff!=0 );
  i = sqlite3Strlen30NN(zColAff);
  if( i ){
    if( iReg ){
      sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);

    /* Compute data for all columns of the new entry, beginning
    ** with the first column.
    */
    nHidden = 0;
    iRegStore = regRowid+1;
    for(i=0; i<pTab->nCol; i++, iRegStore++){
      int k;
      assert( i>=nHidden );
      assert( iRegStore==sqlite3ColumnOfTable(pTab,i)+regRowid+1 );
      if( i==pTab->iPKey ){
        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
        ** Whenever this column is read, the rowid will be substituted
        ** in its place.  Hence, fill this column with a NULL to avoid
        ** taking up data space with information that will never be used.
        ** As there may be shallow copies of this value, make it a soft-NULL */
        sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
        continue;
      }

      if( pTab->aCol[i].colFlags & COLFLAG_NOINSERT ){

        nHidden++;
        if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ){
          /* Virtual columns are no stored */
          iRegStore--;
        }else{
          /* Hidden and stored columns get the default value */
          sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
        }
        continue;
      }
      if( pColumn ){
        for(j=0; j<pColumn->nId && pColumn->a[j].idx!=i; j++){}
        if( j>=pColumn->nId ){
          /* A column not named in the insert column list gets its
          ** default value */
          sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
          continue;
        }
        k = j;
      }else if( nColumn==0 ){
        sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
        continue;
      }else{


        k = i - nHidden;
      }



      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore); 
      }else if( pSelect ){
        if( regFromSelect!=regData ){
          sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
        }
      }else{
        sqlite3ExprCode(pParse, pList->a[k].pExpr, iRegStore);
      }
    }

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.
    */
#ifndef SQLITE_OMIT_VIRTUALTABLE

#define COLFLAG_PRIMKEY   0x0001   /* Column is part of the primary key */
#define COLFLAG_HIDDEN    0x0002   /* A hidden column in a virtual table */
#define COLFLAG_HASTYPE   0x0004   /* Type name follows column name */
#define COLFLAG_UNIQUE    0x0008   /* Column def contains "UNIQUE" or "PK" */
#define COLFLAG_SORTERREF 0x0010   /* Use sorter-refs with this column */
#define COLFLAG_VIRTUAL   0x0020   /* GENERATED ALWAYS AS ... VIRTUAL */
#define COLFLAG_STORED    0x0040   /* GENERATED ALWAYS AS ... STORED */
#define COLFLAG_BUSY      0x0080   /* Blocks recursion on VIRTUAL columns */
#define COLFLAG_GENERATED 0x0060   /* Combo: _STORED, _VIRTUAL */
#define COLFLAG_NOINSERT  0x0062   /* Combo: _HIDDEN, _STORED, _VIRTUAL */

/*
** A "Collating Sequence" is defined by an instance of the following
** structure. Conceptually, a collating sequence consists of a name and
** a comparison routine that defines the order of that sequence.