SQLite

      assert(pParse->nTab==1);
      sqlite3MayAbort(pParse);
      sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
      sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
      pParse->nTab = 2;
      addrTop = sqlite3VdbeCurrentAddr(v) + 1;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);





      pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect);
      if( pSelTab==0 ) return;
      assert( p->aCol==0 );
      p->nCol = pSelTab->nCol;
      p->aCol = pSelTab->aCol;
      pSelTab->nCol = 0;
      pSelTab->aCol = 0;
      sqlite3DeleteTable(db, pSelTab);
      sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
      sqlite3Select(pParse, pSelect, &dest);
      sqlite3VdbeEndCoroutine(v, regYield);
      sqlite3VdbeJumpHere(v, addrTop - 1);
      addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);
      sqlite3TableAffinity(v, p, 0);
      sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);
      sqlite3VdbeGoto(v, addrInsLoop);

  char const *zOrigDb = 0;
  char const *zOrigTab = 0;
  char const *zOrigCol = 0;
#endif

  assert( pExpr!=0 );
  assert( pNC->pSrcList!=0 );
  assert( pExpr->op!=TK_AGG_COLUMN );  /* This routine runes before aggregates
                                       ** are processed */
  switch( pExpr->op ){

    case TK_COLUMN: {
      /* The expression is a column. Locate the table the column is being
      ** extracted from in NameContext.pSrcList. This table may be real
      ** database table or a subquery.
      */
      Table *pTab = 0;            /* Table structure column is extracted from */
      Select *pS = 0;             /* Select the column is extracted from */
      int iCol = pExpr->iColumn;  /* Index of column in pTab */


      while( pNC && !pTab ){
        SrcList *pTabList = pNC->pSrcList;
        for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
        if( j<pTabList->nSrc ){
          pTab = pTabList->a[j].pTab;
          pS = pTabList->a[j].pSelect;
        }else{

      /* If the column contains an "AS <name>" phrase, use <name> as the name */
    }else{
      Expr *pColExpr = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
      while( pColExpr->op==TK_DOT ){
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      assert( pColExpr->op!=TK_AGG_COLUMN );
      if( pColExpr->op==TK_COLUMN ){

        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        Table *pTab = pColExpr->pTab;
        assert( pTab!=0 );
        if( iCol<0 ) iCol = pTab->iPKey;
        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = pColExpr->u.zToken;
      }else{
        /* Use the original text of the column expression as its name */

} {a 1 n 3}
do_test colname-9.211 {
  execsql2 {SELECT t1.a AS n, v3.a FROM t1 JOIN v3}
} {n 1 a 3}
do_test colname-9.210 {
  execsql2 {SELECT t1.a, v3.a AS n FROM t1 JOIN v3}
} {a 1 n 3}

# 2017-12-23:  Ticket https://www.sqlite.org/src/info/3b4450072511e621
# Inconsistent column names in CREATE TABLE AS
#
# Verify that the names of columns in the created table of a CREATE TABLE AS
# are the same as the names of result columns in the SELECT statement.
#
do_execsql_test colname-9.300 {
  DROP TABLE IF EXISTS t1;
  DROP TABLE IF EXISTS t2;
  CREATE TABLE t1(aaa INT);
  INSERT INTO t1(aaa) VALUES(123);
}
do_test colname-9.310 {
  execsql2 {SELECT BBb FROM (SELECT aaa AS Bbb FROM t1)}
} {Bbb 123}
do_execsql_test colname-9.320 {
  CREATE TABLE t2 AS SELECT BBb FROM (SELECT aaa AS Bbb FROM t1);
  SELECT name FROM pragma_table_info('t2');
} {Bbb}


# Make sure the quotation marks get removed from the column names
# when constructing a new table from an aggregate SELECT.
# Email from Juergen Palm on 2017-07-11.
#
do_execsql_test colname-10.100 {
  DROP TABLE IF EXISTS t1;