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SQLite training in Houston TX on 2019-11-05 (details)
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Overview
Comment:Improvements to the data-structure explain subsystem. Most queries now give a reasonably detailed graph of their parse tree.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | tree-explain
Files: files | file ages | folders
SHA1: 0aa7d3d2346bdddcc4e1e25ee26d13c8594885e5
User & Date: drh 2011-12-07 01:23:51
Context
2011-12-07
01:47
Bug fix in sqlite3SelectDup(). Make sure the pNext pointer is valid. check-in: 7e5b56b1 user: drh tags: tree-explain
01:23
Improvements to the data-structure explain subsystem. Most queries now give a reasonably detailed graph of their parse tree. check-in: 0aa7d3d2 user: drh tags: tree-explain
2011-12-06
19:44
Begin adding the data-structure explaining subsystem. All is contained within check-in: 79ae51c5 user: drh tags: tree-explain
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/expr.c.

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  return inReg;
}

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable explanation of an expression tree.
*/
void sqlite3ExplainExpr(Vdbe *pOut, Expr *p){



  if( p==0 ){







































    sqlite3ExplainPrintf(pOut, "(C-null)");
    return;

  }




  if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){



































    sqlite3ExplainPrintf(pOut, "(%s", p->u.zToken);





































  }else{



















    sqlite3ExplainPrintf(pOut, "(op=%d", p->op);



  }


























  if( p->pLeft ){




    sqlite3ExplainPrintf(pOut, " left=");
    sqlite3ExplainExpr(pOut, p->pLeft);




  }
  if( p->pRight ){








    sqlite3ExplainPrintf(pOut, " right=");





    sqlite3ExplainExpr(pOut, p->pRight);



  }

















  sqlite3ExplainPrintf(pOut, ")");






}

#endif /* defined(SQLITE_DEBUG) */

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable explanation of an expression list.
*/
void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
  int i;
  if( pList==0 ){
    sqlite3ExplainPrintf(pOut, "(empty-list)");
    return;
  }



  sqlite3ExplainPush(pOut);
  for(i=0; i<pList->nExpr; i++){
    sqlite3ExplainPrintf(pOut, "%02d: ", i);
    sqlite3ExplainPush(pOut);
    sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
    sqlite3ExplainPop(pOut);
    if( i<pList->nExpr-1 ){
      sqlite3ExplainNL(pOut);
    }
  }
  sqlite3ExplainPop(pOut);

}
#endif /* SQLITE_DEBUG */

/*
** Return TRUE if pExpr is an constant expression that is appropriate
** for factoring out of a loop.  Appropriate expressions are:
**







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  return inReg;
}

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable explanation of an expression tree.
*/
void sqlite3ExplainExpr(Vdbe *pOut, Expr *pExpr){
  int op;                   /* The opcode being coded */
  const char *zBinOp = 0;   /* Binary operator */
  const char *zUniOp = 0;   /* Unary operator */
  if( pExpr==0 ){
    op = TK_NULL;
  }else{
    op = pExpr->op;
  }
  switch( op ){
    case TK_AGG_COLUMN: {
      sqlite3ExplainPrintf(pOut, "AGG_COLUMN(%s:%d:%d)",
            pExpr->pTab->zName, pExpr->iTable, pExpr->iColumn);
      break;
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        sqlite3ExplainPrintf(pOut, "COLUMN(%d)", pExpr->iColumn);
      }else{
        sqlite3ExplainPrintf(pOut, "COLUMN(%s:%d:%d)",
            pExpr->pTab->zName, pExpr->iTable, pExpr->iColumn);
      }
      break;
    }
    case TK_INTEGER: {
      if( pExpr->flags & EP_IntValue ){
        sqlite3ExplainPrintf(pOut, "INTEGER(%d)", pExpr->u.iValue);
      }else{
        sqlite3ExplainPrintf(pOut, "INTEGER(%s)", pExpr->u.zToken);
      }
      break;
    }
#ifndef SQLITE_OMIT_FLOATING_POINT
    case TK_FLOAT: {
      sqlite3ExplainPrintf(pOut,"REAL(%s)", pExpr->u.zToken);
      break;
    }
#endif
    case TK_STRING: {
      sqlite3ExplainPrintf(pOut,"STRING(%s)", pExpr->u.zToken);
      break;
    }
    case TK_NULL: {
      sqlite3ExplainPrintf(pOut,"NULL");

      break;
    }
#ifndef SQLITE_OMIT_BLOB_LITERAL
    case TK_BLOB: {
      int n;
      const char *z;
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
      assert( pExpr->u.zToken[1]=='\'' );
      z = &pExpr->u.zToken[2];
      n = sqlite3Strlen30(z) - 1;
      assert( z[n]=='\'' );
      sqlite3ExplainPrintf(pOut,"BLOB(%.*s)", n, z);
      break;
    }
#endif
    case TK_VARIABLE: {
      sqlite3ExplainPrintf(pOut,"VARIABLE(%s,%d)",
                           pExpr->u.zToken, pExpr->iColumn);
      break;
    }
    case TK_REGISTER: {
      sqlite3ExplainPrintf(pOut,"REGISTER(%d)", pExpr->iTable);
      break;
    }
    case TK_AS: {
      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      break;
    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      const char *zAff = "unk";
      switch( sqlite3AffinityType(pExpr->u.zToken) ){
        case SQLITE_AFF_TEXT:    zAff = "TEXT";     break;
        case SQLITE_AFF_NONE:    zAff = "NONE";     break;
        case SQLITE_AFF_NUMERIC: zAff = "NUMERIC";  break;
        case SQLITE_AFF_INTEGER: zAff = "INTEGER";  break;
        case SQLITE_AFF_REAL:    zAff = "REAL";     break;
      }
      sqlite3ExplainPrintf(pOut, "CAST-%s(", zAff);
      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      sqlite3ExplainPrintf(pOut, ")");
      break;
    }
#endif /* SQLITE_OMIT_CAST */
    case TK_LT:      zBinOp = "LT";     break;
    case TK_LE:      zBinOp = "LE";     break;
    case TK_GT:      zBinOp = "GT";     break;
    case TK_GE:      zBinOp = "GE";     break;
    case TK_NE:      zBinOp = "NE";     break;
    case TK_EQ:      zBinOp = "EQ";     break;
    case TK_IS:      zBinOp = "IS";     break;
    case TK_ISNOT:   zBinOp = "ISNOT";  break;
    case TK_AND:     zBinOp = "AND";    break;
    case TK_OR:      zBinOp = "OR";     break;
    case TK_PLUS:    zBinOp = "ADD";    break;
    case TK_STAR:    zBinOp = "MUL";    break;
    case TK_MINUS:   zBinOp = "SUB";    break;
    case TK_REM:     zBinOp = "REM";    break;
    case TK_BITAND:  zBinOp = "BITAND"; break;
    case TK_BITOR:   zBinOp = "BITOR";  break;
    case TK_SLASH:   zBinOp = "DIV";    break;
    case TK_LSHIFT:  zBinOp = "LSHIFT"; break;
    case TK_RSHIFT:  zBinOp = "RSHIFT"; break;
    case TK_CONCAT:  zBinOp = "CONCAT"; break;

    case TK_UMINUS:  zUniOp = "UMINUS"; break;
    case TK_UPLUS:   zUniOp = "UPLUS";  break;
    case TK_BITNOT:  zUniOp = "BITNOT"; break;
    case TK_NOT:     zUniOp = "NOT";    break;
    case TK_ISNULL:  zUniOp = "ISNULL"; break;
    case TK_NOTNULL: zUniOp = "NOTNULL"; break;

    case TK_AGG_FUNCTION:
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pFarg;       /* List of function arguments */
      if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
        pFarg = 0;
      }else{
        pFarg = pExpr->x.pList;
      }
      sqlite3ExplainPrintf(pOut, "%sFUNCTION:%s(",
                           op==TK_AGG_FUNCTION ? "AGG_" : "",
                           pExpr->u.zToken);
      if( pFarg ){
        sqlite3ExplainExprList(pOut, pFarg);
      }
      sqlite3ExplainPrintf(pOut, ")");
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS: {
      sqlite3ExplainPrintf(pOut, "EXISTS(");
      sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
      sqlite3ExplainPrintf(pOut,")");
      break;
    }
    case TK_SELECT: {
      sqlite3ExplainPrintf(pOut, "(");
      sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
      sqlite3ExplainPrintf(pOut, ")");
      break;
    }
    case TK_IN: {
      sqlite3ExplainPrintf(pOut, "IN(");
      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      sqlite3ExplainPrintf(pOut, ",");
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
      }else{
        sqlite3ExplainExprList(pOut, pExpr->x.pList);
      }
      sqlite3ExplainPrintf(pOut, ")");
      break;
    }
#endif /* SQLITE_OMIT_SUBQUERY */

    /*
    **    x BETWEEN y AND z
    **
    ** This is equivalent to
    **
    **    x>=y AND x<=z
    **
    ** X is stored in pExpr->pLeft.
    ** Y is stored in pExpr->pList->a[0].pExpr.
    ** Z is stored in pExpr->pList->a[1].pExpr.
    */
    case TK_BETWEEN: {
      Expr *pX = pExpr->pLeft;
      Expr *pY = pExpr->x.pList->a[0].pExpr;
      Expr *pZ = pExpr->x.pList->a[1].pExpr;
      sqlite3ExplainPrintf(pOut, "BETWEEN(");
      sqlite3ExplainExpr(pOut, pX);
      sqlite3ExplainPrintf(pOut, ",");
      sqlite3ExplainExpr(pOut, pY);
      sqlite3ExplainPrintf(pOut, ",");
      sqlite3ExplainExpr(pOut, pZ);
      sqlite3ExplainPrintf(pOut, ")");
      break;
    }

    case TK_TRIGGER: {
      /* If the opcode is TK_TRIGGER, then the expression is a reference
      ** to a column in the new.* or old.* pseudo-tables available to
      ** trigger programs. In this case Expr.iTable is set to 1 for the
      ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
      ** is set to the column of the pseudo-table to read, or to -1 to
      ** read the rowid field.
      */
      sqlite3ExplainPrintf(pOut, "%s(%d)", 
          pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
      break;
    }
    case TK_CASE: {
      sqlite3ExplainPrintf(pOut, "CASE(");
      sqlite3ExplainExpr(pOut, pExpr->pLeft);
      sqlite3ExplainPrintf(pOut, ",");
      sqlite3ExplainExprList(pOut, pExpr->x.pList);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      const char *zType = "unk";
      switch( pExpr->affinity ){
        case OE_Rollback:   zType = "rollback";  break;
        case OE_Abort:      zType = "abort";     break;
        case OE_Fail:       zType = "fail";      break;
        case OE_Ignore:     zType = "ignore";    break;
      }
      sqlite3ExplainPrintf(pOut, "RAISE-%s(%s)", zType, pExpr->u.zToken);
      break;
    }
#endif
  }
  if( zBinOp ){
    sqlite3ExplainPrintf(pOut,"%s(", zBinOp);
    sqlite3ExplainExpr(pOut, pExpr->pLeft);
    sqlite3ExplainPrintf(pOut,",");
    sqlite3ExplainExpr(pOut, pExpr->pRight);
    sqlite3ExplainPrintf(pOut,")");
  }else if( zUniOp ){
    sqlite3ExplainPrintf(pOut,"%s(", zUniOp);
    sqlite3ExplainExpr(pOut, pExpr->pLeft);
    sqlite3ExplainPrintf(pOut,")");
  }
}
#endif /* defined(SQLITE_DEBUG) */

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable explanation of an expression list.
*/
void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
  int i;
  if( pList==0 || pList->nExpr==0 ){
    sqlite3ExplainPrintf(pOut, "(empty-list)");
    return;

  }else if( pList->nExpr==1 ){
    sqlite3ExplainExpr(pOut, pList->a[0].pExpr);
  }else{
    sqlite3ExplainPush(pOut);
    for(i=0; i<pList->nExpr; i++){
      sqlite3ExplainPrintf(pOut, "item[%d] = ", i);
      sqlite3ExplainPush(pOut);
      sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
      sqlite3ExplainPop(pOut);
      if( i<pList->nExpr-1 ){
        sqlite3ExplainNL(pOut);
      }
    }
    sqlite3ExplainPop(pOut);
  }
}
#endif /* SQLITE_DEBUG */

/*
** Return TRUE if pExpr is an constant expression that is appropriate
** for factoring out of a loop.  Appropriate expressions are:
**

Changes to src/select.c.

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  return rc;
}

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable description of a the Select object.
*/
void sqlite3ExplainSelect(Vdbe *pVdbe, Select *p){
  if( p==0 ){
    sqlite3ExplainPrintf(pVdbe, "(empty-select)");
    return;
  }
  sqlite3ExplainPrintf(pVdbe, "SELECT ");
  sqlite3ExplainPush(pVdbe);
  sqlite3ExplainExprList(pVdbe, p->pEList);
  sqlite3ExplainNL(pVdbe);
  sqlite3ExplainPop(pVdbe);
  if( p->pSrc && p->pSrc->nSrc ){
    int i;
    sqlite3ExplainPrintf(pVdbe, "  FROM ");
    sqlite3ExplainPush(pVdbe);
    for(i=0; i<p->pSrc->nSrc; i++){
      struct SrcList_item *pItem = &p->pSrc->a[i];
      sqlite3ExplainPrintf(pVdbe, "%02d: ", i);
      sqlite3ExplainPush(pVdbe);
      if( pItem->pSelect ){
        sqlite3ExplainSelect(pVdbe, pItem->pSelect);
      }else if( pItem->zName ){
        sqlite3ExplainPrintf(pVdbe, "%s", pItem->zName);
      }
      if( pItem->pTab ){
        sqlite3ExplainPrintf(pVdbe, " (table: %s)", pItem->pTab->zName);




      }
      if( pItem->zAlias ){
        sqlite3ExplainPrintf(pVdbe, " (AS %s)", pItem->zAlias);
      }
      sqlite3ExplainNL(pVdbe);
      sqlite3ExplainPop(pVdbe);
    }
    sqlite3ExplainPop(pVdbe);
  }
  if( p->pWhere ){
    sqlite3ExplainPrintf(pVdbe, " WHERE ");
    sqlite3ExplainExpr(pVdbe, p->pWhere);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pGroupBy ){
    sqlite3ExplainPrintf(pVdbe, " GROUP BY ");
    sqlite3ExplainExprList(pVdbe, p->pGroupBy);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pHaving ){
    sqlite3ExplainPrintf(pVdbe, "HAVING ");
    sqlite3ExplainExpr(pVdbe, p->pHaving);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pOrderBy ){
    sqlite3ExplainPrintf(pVdbe, " ORDER BY ");
    sqlite3ExplainExprList(pVdbe, p->pOrderBy);
    sqlite3ExplainNL(pVdbe);
  }

























  sqlite3ExplainPrintf(pVdbe, "   END");

}

/* End of the structure debug printing code
*****************************************************************************/
#endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */







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4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
  return rc;
}

#if defined(SQLITE_DEBUG)
/*
** Generate a human-readable description of a the Select object.
*/
static void explainOneSelect(Vdbe *pVdbe, Select *p){




  sqlite3ExplainPrintf(pVdbe, "SELECT ");

  sqlite3ExplainExprList(pVdbe, p->pEList);
  sqlite3ExplainNL(pVdbe);

  if( p->pSrc && p->pSrc->nSrc ){
    int i;
    sqlite3ExplainPrintf(pVdbe, "FROM ");
    sqlite3ExplainPush(pVdbe);
    for(i=0; i<p->pSrc->nSrc; i++){
      struct SrcList_item *pItem = &p->pSrc->a[i];
      sqlite3ExplainPrintf(pVdbe, "src[%d] = ", i);

      if( pItem->pSelect ){
        sqlite3ExplainSelect(pVdbe, pItem->pSelect);
      }else if( pItem->zName ){
        sqlite3ExplainPrintf(pVdbe, "%s", pItem->zName);
      }
      if( pItem->pTab ){
        sqlite3ExplainPrintf(pVdbe, " (name=%s:%d)",
                             pItem->pTab->zName, pItem->iCursor);
      }
      if( pItem->jointype & JT_LEFT ){
        sqlite3ExplainPrintf(pVdbe, " LEFT-JOIN");
      }
      if( pItem->zAlias ){
        sqlite3ExplainPrintf(pVdbe, " (AS %s)", pItem->zAlias);
      }
      sqlite3ExplainNL(pVdbe);

    }
    sqlite3ExplainPop(pVdbe);
  }
  if( p->pWhere ){
    sqlite3ExplainPrintf(pVdbe, "WHERE ");
    sqlite3ExplainExpr(pVdbe, p->pWhere);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pGroupBy ){
    sqlite3ExplainPrintf(pVdbe, "GROUPBY ");
    sqlite3ExplainExprList(pVdbe, p->pGroupBy);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pHaving ){
    sqlite3ExplainPrintf(pVdbe, "HAVING ");
    sqlite3ExplainExpr(pVdbe, p->pHaving);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pOrderBy ){
    sqlite3ExplainPrintf(pVdbe, "ORDERBY ");
    sqlite3ExplainExprList(pVdbe, p->pOrderBy);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pLimit ){
    sqlite3ExplainPrintf(pVdbe, "LIMIT ");
    sqlite3ExplainExpr(pVdbe, p->pLimit);
    sqlite3ExplainNL(pVdbe);
  }
  if( p->pOffset ){
    sqlite3ExplainPrintf(pVdbe, "OFFSET ");
    sqlite3ExplainExpr(pVdbe, p->pOffset);
    sqlite3ExplainNL(pVdbe);
  }
}
void sqlite3ExplainSelect(Vdbe *pVdbe, Select *p){
  if( p==0 ){
    sqlite3ExplainPrintf(pVdbe, "(null-select)");
    return;
  }
  while( p->pPrior ) p = p->pPrior;
  sqlite3ExplainPush(pVdbe);
  while( p ){
    explainOneSelect(pVdbe, p);
    p = p->pNext;
    if( p==0 ) break;
    sqlite3ExplainNL(pVdbe);
    sqlite3ExplainPrintf(pVdbe, "%s\n", selectOpName(p->op));
  }
  sqlite3ExplainPrintf(pVdbe, "END");
  sqlite3ExplainPop(pVdbe);
}

/* End of the structure debug printing code
*****************************************************************************/
#endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */