SQLite

    FUNCTION(rtrim,              1, 2, 0, trimFunc         ),
    FUNCTION(rtrim,              2, 2, 0, trimFunc         ),
    FUNCTION(trim,               1, 3, 0, trimFunc         ),
    FUNCTION(trim,               2, 3, 0, trimFunc         ),
    FUNCTION(min,               -1, 0, 1, minmaxFunc       ),
    FUNCTION(min,                0, 0, 1, 0                ),
    WAGGREGATE(min, 1, 0, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,
                                          SQLITE_FUNC_MINMAX ),
                                 SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER ),
    FUNCTION(max,               -1, 1, 1, minmaxFunc       ),
    FUNCTION(max,                0, 1, 1, 0                ),
    WAGGREGATE(max, 1, 1, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,
                                          SQLITE_FUNC_MINMAX ),
                                 SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER ),
    FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
    FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
    FUNCTION(instr,              2, 0, 0, instrFunc        ),
    FUNCTION(printf,            -1, 0, 0, printfFunc       ),
    FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),
    FUNCTION(char,              -1, 0, 0, charFunc         ),
    FUNCTION(abs,                1, 0, 0, absFunc          ),

    FUNCTION(substr,             3, 0, 0, substrFunc       ),
    FUNCTION(substring,          2, 0, 0, substrFunc       ),
    FUNCTION(substring,          3, 0, 0, substrFunc       ),
    WAGGREGATE(sum,   1,0,0, sumStep, sumFinalize, sumFinalize, sumInverse, 0),
    WAGGREGATE(total, 1,0,0, sumStep,totalFinalize,totalFinalize,sumInverse, 0),
    WAGGREGATE(avg,   1,0,0, sumStep, avgFinalize, avgFinalize, sumInverse, 0),
    WAGGREGATE(count, 0,0,0, countStep, 
        countFinalize, countFinalize, countInverse, SQLITE_FUNC_COUNT  ),
        countFinalize, countFinalize, countInverse,
        SQLITE_FUNC_COUNT|SQLITE_FUNC_ANYORDER  ),
    WAGGREGATE(count, 1,0,0, countStep, 
        countFinalize, countFinalize, countInverse, 0  ),
        countFinalize, countFinalize, countInverse, SQLITE_FUNC_ANYORDER ),
    WAGGREGATE(group_concat, 1, 0, 0, groupConcatStep, 
        groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),
    WAGGREGATE(group_concat, 2, 0, 0, groupConcatStep, 
        groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),
  
    LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
#ifdef SQLITE_CASE_SENSITIVE_LIKE

          while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
            pExpr->op2++;
            pNC2 = pNC2->pNext;
          }
          assert( pDef!=0 || IN_RENAME_OBJECT );
          if( pNC2 && pDef ){
            assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
            assert( SQLITE_FUNC_ANYORDER==NC_OrderAgg );
            testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
            testcase( (pDef->funcFlags & SQLITE_FUNC_ANYORDER)!=0 );
            pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);

            pNC2->ncFlags |= NC_HasAgg 
              | ((pDef->funcFlags^SQLITE_FUNC_ANYORDER)
                  & (SQLITE_FUNC_MINMAX|SQLITE_FUNC_ANYORDER));
          }
        }
        pNC->ncFlags |= savedAllowFlags;
      }
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */

      Select *pSub = p->pSrc->a[0].pSelect;
      assert( p->pSrc->nSrc==1 && p->pOrderBy );
      assert( pSub->pPrior && pSub->pOrderBy==0 );
      pSub->pOrderBy = p->pOrderBy;
      p->pOrderBy = 0;
    }
  
    /* Recursively resolve names in all subqueries
    /* Recursively resolve names in all subqueries in the FROM clause
    */
    for(i=0; i<p->pSrc->nSrc; i++){
      SrcItem *pItem = &p->pSrc->a[i];
      if( pItem->pSelect && (pItem->pSelect->selFlags & SF_Resolved)==0 ){
        int nRef = pOuterNC ? pOuterNC->nRef : 0;
        const char *zSavedContext = pParse->zAuthContext;

    /* If there are no aggregate functions in the result-set, and no GROUP BY 
    ** expression, do not allow aggregates in any of the other expressions.
    */
    assert( (p->selFlags & SF_Aggregate)==0 );
    pGroupBy = p->pGroupBy;
    if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
      assert( NC_MinMaxAgg==SF_MinMaxAgg );
      assert( NC_OrderAgg==SF_OrderByReqd );
      p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);
      p->selFlags |= SF_Aggregate | (sNC.ncFlags&(NC_MinMaxAgg|NC_OrderAgg));
    }else{
      sNC.ncFlags &= ~NC_AllowAgg;
    }
  
    /* Add the output column list to the name-context before parsing the
    ** other expressions in the SELECT statement. This is so that
    ** expressions in the WHERE clause (etc.) can refer to expressions by

  NameContext *pNC,       /* Namespace to resolve expressions in. */
  Expr *pExpr             /* The expression to be analyzed. */
){
  int savedHasAgg;
  Walker w;

  if( pExpr==0 ) return SQLITE_OK;
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
  w.pParse = pNC->pParse;
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = (pNC->ncFlags & NC_NoSelect) ? 0 : resolveSelectStep;
  w.xSelectCallback2 = 0;
  w.u.pNC = pNC;
#if SQLITE_MAX_EXPR_DEPTH>0
  w.pParse->nHeight += pExpr->nHeight;

  Walker w;
  if( pList==0 ) return WRC_Continue;
  w.pParse = pNC->pParse;
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = resolveSelectStep;
  w.xSelectCallback2 = 0;
  w.u.pNC = pNC;
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
  for(i=0; i<pList->nExpr; i++){
    Expr *pExpr = pList->a[i].pExpr;
    if( pExpr==0 ) continue;
#if SQLITE_MAX_EXPR_DEPTH>0
    w.pParse->nHeight += pExpr->nHeight;
    if( sqlite3ExprCheckHeight(w.pParse, w.pParse->nHeight) ){
      return WRC_Abort;
    }
#endif
    sqlite3WalkExpr(&w, pExpr);
#if SQLITE_MAX_EXPR_DEPTH>0
    w.pParse->nHeight -= pExpr->nHeight;
#endif
    assert( EP_Agg==NC_HasAgg );
    assert( EP_Win==NC_HasWin );
    testcase( pNC->ncFlags & NC_HasAgg );
    testcase( pNC->ncFlags & NC_HasWin );
    if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin) ){
    if( pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg) ){
      ExprSetProperty(pExpr, pNC->ncFlags & (NC_HasAgg|NC_HasWin) );
      savedHasAgg |= pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
      pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
      savedHasAgg |= pNC->ncFlags &
                          (NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
      pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin|NC_OrderAgg);
    }
    if( w.pParse->nErr>0 ) return WRC_Abort;
  }
  pNC->ncFlags |= savedHasAgg;
  return WRC_Continue;
}

    ** Flattening an aggregate subquery is only possible if the outer query
    ** is not a join.  But if the outer query is not a join, then the subquery
    ** will be implemented as a co-routine and there is no advantage to
    ** flattening in that case.
    */
    if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
    assert( pSub->pGroupBy==0 );

    /* If a FROM-clause subquery has an ORDER BY clause that is not
    ** really doing anything, then delete it now so that it does not
    ** interfere with query flattening.  See the discussion at
    ** https://sqlite.org/forum/forumpost/2d76f2bcf65d256a
    **
    ** Beware of these cases where the ORDER BY clause may not be safely
    ** omitted:
    **
    **    (1)   There is also a LIMIT clause
    **    (2)   The subquery was added to help with window-function
    **          processing
    **    (3)   The subquery is in the FROM clause of an UPDATE
    **    (4)   The outer query uses an aggregate function other than
    **          the built-in count(), min(), or max().
    **    (5)   The ORDER BY isn't going to accomplish anything because
    **          one of:
    **            (a)  The outer query has a different ORDER BY clause
    **            (b)  The subquery is part of a join
    **          See forum post 062d576715d277c8
    */
    if( pSub->pOrderBy!=0
     && (p->pOrderBy!=0 || pTabList->nSrc>1)      /* Condition (5) */
     && pSub->pLimit==0                           /* Condition (1) */
     && (pSub->selFlags & SF_OrderByReqd)==0      /* Condition (2) */
     && (p->selFlags & SF_OrderByReqd)==0         /* Condition (3) and (4) */
     && OptimizationEnabled(db, SQLITE_OmitOrderBy)
    ){
      SELECTTRACE(0x100,pParse,p,
                ("omit superfluous ORDER BY on %r FROM-clause subquery\n",i+1));
      sqlite3ExprListDelete(db, pSub->pOrderBy);
      pSub->pOrderBy = 0;
    }

    /* If the outer query contains a "complex" result set (that is,
    ** if the result set of the outer query uses functions or subqueries)
    ** and if the subquery contains an ORDER BY clause and if
    ** it will be implemented as a co-routine, then do not flatten.  This
    ** restriction allows SQL constructs like this:
    **

   /* TH3 expects this value  ^^^^^^^^^^ to be 0x0000800. Don't change it */
#define SQLITE_PushDown       0x00001000 /* The push-down optimization */
#define SQLITE_SimplifyJoin   0x00002000 /* Convert LEFT JOIN to JOIN */
#define SQLITE_SkipScan       0x00004000 /* Skip-scans */
#define SQLITE_PropagateConst 0x00008000 /* The constant propagation opt */
#define SQLITE_MinMaxOpt      0x00010000 /* The min/max optimization */
#define SQLITE_SeekScan       0x00020000 /* The OP_SeekScan optimization */
#define SQLITE_OmitOrderBy    0x00040000 /* Omit pointless ORDER BY */
#define SQLITE_AllOpts        0xffffffff /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
#define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)

/*
** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And
** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There
** are assert() statements in the code to verify this.
**
** Value constraints (enforced via assert()):
**     SQLITE_FUNC_MINMAX    ==  NC_MinMaxAgg      == SF_MinMaxAgg
**     SQLITE_FUNC_LENGTH    ==  OPFLAG_LENGTHARG
**     SQLITE_FUNC_TYPEOF    ==  OPFLAG_TYPEOFARG
**     SQLITE_FUNC_CONSTANT  ==  SQLITE_DETERMINISTIC from the API
**     SQLITE_FUNC_DIRECT    ==  SQLITE_DIRECTONLY from the API
**     SQLITE_FUNC_UNSAFE    ==  SQLITE_INNOCUOUS
**     SQLITE_FUNC_MINMAX      ==  NC_MinMaxAgg      == SF_MinMaxAgg
**     SQLITE_FUNC_ANYORDER    ==  NC_OrderAgg       == SF_OrderByReqd
**     SQLITE_FUNC_LENGTH      ==  OPFLAG_LENGTHARG
**     SQLITE_FUNC_TYPEOF      ==  OPFLAG_TYPEOFARG
**     SQLITE_FUNC_CONSTANT    ==  SQLITE_DETERMINISTIC from the API
**     SQLITE_FUNC_DIRECT      ==  SQLITE_DIRECTONLY from the API
**     SQLITE_FUNC_UNSAFE      ==  SQLITE_INNOCUOUS
**     SQLITE_FUNC_ENCMASK   depends on SQLITE_UTF* macros in the API
*/
#define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
#define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */
#define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */
#define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */
#define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/

#define SQLITE_FUNC_OFFSET   0x8000 /* Built-in sqlite_offset() function */
#define SQLITE_FUNC_WINDOW   0x00010000 /* Built-in window-only function */
#define SQLITE_FUNC_INTERNAL 0x00040000 /* For use by NestedParse() only */
#define SQLITE_FUNC_DIRECT   0x00080000 /* Not for use in TRIGGERs or VIEWs */
#define SQLITE_FUNC_SUBTYPE  0x00100000 /* Result likely to have sub-type */
#define SQLITE_FUNC_UNSAFE   0x00200000 /* Function has side effects */
#define SQLITE_FUNC_INLINE   0x00400000 /* Functions implemented in-line */
#define SQLITE_FUNC_ANYORDER 0x08000000 /* count/min/max aggregate */

/* Identifier numbers for each in-line function */
#define INLINEFUNC_coalesce             0
#define INLINEFUNC_implies_nonnull_row  1
#define INLINEFUNC_expr_implies_expr    2
#define INLINEFUNC_expr_compare         3      
#define INLINEFUNC_affinity             4

  Select *pWinSelect;  /* SELECT statement for any window functions */
};

/*
** Allowed values for the NameContext, ncFlags field.
**
** Value constraints (all checked via assert()):
**    NC_HasAgg    == SF_HasAgg    == EP_Agg
**    NC_MinMaxAgg == SF_MinMaxAgg == SQLITE_FUNC_MINMAX
**    NC_HasAgg    == SF_HasAgg       == EP_Agg
**    NC_MinMaxAgg == SF_MinMaxAgg    == SQLITE_FUNC_MINMAX
**    NC_OrderAgg  == SF_OrderByReqd  == SQLITE_FUNC_ANYORDER
**    NC_HasWin    == EP_Win
**
*/
#define NC_AllowAgg  0x00001  /* Aggregate functions are allowed here */
#define NC_PartIdx   0x00002  /* True if resolving a partial index WHERE */
#define NC_IsCheck   0x00004  /* True if resolving a CHECK constraint */
#define NC_GenCol    0x00008  /* True for a GENERATED ALWAYS AS clause */
#define NC_HasAgg    0x00010  /* One or more aggregate functions seen */
#define NC_IdxExpr   0x00020  /* True if resolving columns of CREATE INDEX */
#define NC_SelfRef   0x0002e  /* Combo: PartIdx, isCheck, GenCol, and IdxExpr */
#define NC_VarSelect 0x00040  /* A correlated subquery has been seen */
#define NC_UEList    0x00080  /* True if uNC.pEList is used */
#define NC_UAggInfo  0x00100  /* True if uNC.pAggInfo is used */
#define NC_UUpsert   0x00200  /* True if uNC.pUpsert is used */
#define NC_UBaseReg  0x00400  /* True if uNC.iBaseReg is used */
#define NC_MinMaxAgg 0x01000  /* min/max aggregates seen.  See note above */
#define NC_Complex   0x02000  /* True if a function or subquery seen */
#define NC_AllowWin  0x04000  /* Window functions are allowed here */
#define NC_HasWin    0x08000  /* One or more window functions seen */
#define NC_IsDDL     0x10000  /* Resolving names in a CREATE statement */
#define NC_InAggFunc 0x20000  /* True if analyzing arguments to an agg func */
#define NC_FromDDL   0x40000  /* SQL text comes from sqlite_schema */
#define NC_NoSelect  0x80000  /* Do not descend into sub-selects */
#define NC_AllowAgg  0x000001 /* Aggregate functions are allowed here */
#define NC_PartIdx   0x000002 /* True if resolving a partial index WHERE */
#define NC_IsCheck   0x000004 /* True if resolving a CHECK constraint */
#define NC_GenCol    0x000008 /* True for a GENERATED ALWAYS AS clause */
#define NC_HasAgg    0x000010 /* One or more aggregate functions seen */
#define NC_IdxExpr   0x000020 /* True if resolving columns of CREATE INDEX */
#define NC_SelfRef   0x00002e /* Combo: PartIdx, isCheck, GenCol, and IdxExpr */
#define NC_VarSelect 0x000040 /* A correlated subquery has been seen */
#define NC_UEList    0x000080 /* True if uNC.pEList is used */
#define NC_UAggInfo  0x000100 /* True if uNC.pAggInfo is used */
#define NC_UUpsert   0x000200 /* True if uNC.pUpsert is used */
#define NC_UBaseReg  0x000400 /* True if uNC.iBaseReg is used */
#define NC_MinMaxAgg 0x001000 /* min/max aggregates seen.  See note above */
#define NC_Complex   0x002000 /* True if a function or subquery seen */
#define NC_AllowWin  0x004000 /* Window functions are allowed here */
#define NC_HasWin    0x008000 /* One or more window functions seen */
#define NC_IsDDL     0x010000 /* Resolving names in a CREATE statement */
#define NC_InAggFunc 0x020000 /* True if analyzing arguments to an agg func */
#define NC_FromDDL   0x040000 /* SQL text comes from sqlite_schema */
#define NC_NoSelect  0x080000 /* Do not descend into sub-selects */
#define NC_OrderAgg 0x8000000 /* Has an aggregate other than count/min/max */

/*
** An instance of the following object describes a single ON CONFLICT
** clause in an upsert.
**
** The pUpsertTarget field is only set if the ON CONFLICT clause includes
** conflict-target clause.  (In "ON CONFLICT(a,b)" the "(a,b)" is the

};

/*
** Allowed values for Select.selFlags.  The "SF" prefix stands for
** "Select Flag".
**
** Value constraints (all checked via assert())
**     SF_HasAgg     == NC_HasAgg
**     SF_MinMaxAgg  == NC_MinMaxAgg     == SQLITE_FUNC_MINMAX
**     SF_FixedLimit == WHERE_USE_LIMIT
**     SF_HasAgg      == NC_HasAgg
**     SF_MinMaxAgg   == NC_MinMaxAgg     == SQLITE_FUNC_MINMAX
**     SF_OrderByReqd == NC_OrderAgg      == SQLITE_FUNC_ANYORDER
**     SF_FixedLimit  == WHERE_USE_LIMIT
*/
#define SF_Distinct      0x0000001 /* Output should be DISTINCT */
#define SF_All           0x0000002 /* Includes the ALL keyword */
#define SF_Resolved      0x0000004 /* Identifiers have been resolved */
#define SF_Aggregate     0x0000008 /* Contains agg functions or a GROUP BY */
#define SF_HasAgg        0x0000010 /* Contains aggregate functions */
#define SF_UsesEphemeral 0x0000020 /* Uses the OpenEphemeral opcode */

#define SF_WinRewrite    0x0100000 /* Window function rewrite accomplished */
#define SF_View          0x0200000 /* SELECT statement is a view */
#define SF_NoopOrderBy   0x0400000 /* ORDER BY is ignored for this query */
#define SF_UFSrcCheck    0x0800000 /* Check pSrc as required by UPDATE...FROM */
#define SF_PushDown      0x1000000 /* SELECT has be modified by push-down opt */
#define SF_MultiPart     0x2000000 /* Has multiple incompatible PARTITIONs */
#define SF_CopyCte       0x4000000 /* SELECT statement is a copy of a CTE */
#define SF_OrderByReqd   0x8000000 /* The ORDER BY clause may not be omitted */

/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**
**     SRT_Union       Store results as a key in a temporary index

          sqlite3ExprDup(db, pChanges->a[i].pExpr, 0)
      );
    }
  }
  pSelect = sqlite3SelectNew(pParse, pList, 
      pSrc, pWhere2, pGrp, 0, pOrderBy2, SF_UFSrcCheck|SF_IncludeHidden, pLimit2
  );
  if( pSelect ) pSelect->selFlags |= SF_OrderByReqd;
  sqlite3SelectDestInit(&dest, eDest, iEph);
  dest.iSDParm2 = (pPk ? pPk->nKeyCol : -1);
  sqlite3Select(pParse, pSelect, &dest);
  sqlite3SelectDelete(db, pSelect);
}

/*

       ("New window-function subquery in FROM clause of (%u/%p)\n",
       p->selId, p));
    p->pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
    if( p->pSrc ){
      Table *pTab2;
      p->pSrc->a[0].pSelect = pSub;
      sqlite3SrcListAssignCursors(pParse, p->pSrc);
      pSub->selFlags |= SF_Expanded;
      pSub->selFlags |= SF_Expanded|SF_OrderByReqd;
      pTab2 = sqlite3ResultSetOfSelect(pParse, pSub, SQLITE_AFF_NONE);
      pSub->selFlags |= (selFlags & SF_Aggregate);
      if( pTab2==0 ){
        /* Might actually be some other kind of error, but in that case
        ** pParse->nErr will be set, so if SQLITE_NOMEM is set, we will get
        ** the correct error message regardless. */
        rc = SQLITE_NOMEM;