frame grammar tmp

src/Interpreters/AggregateDescription.h

@@ -39,6 +39,26 @@ struct WindowFunctionDescription
     std::string dump() const;
 };
 
+struct WindowFrame
+{
+    enum class FrameType { Rows, Groups, Range };
+    enum class OffsetType { Unbounded, Current, Offset };
+
+    // This flag signifies that the frame properties were not set explicitly by
+    // user, but the fields of this structure still have to contain proper values
+    // for the default frame of ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW.
+    bool is_default = true;
+
+    FrameType type = FrameType::Rows;
+
+    /*
+     * We don't need these yet.
+     * OffsetType begin_offset = Unbounded;
+
+     * OffsetType end_offset = Current;
+     */
+};
+
 struct WindowDescription
 {
     std::string window_name;
@@ -54,7 +74,7 @@ struct WindowDescription
     // then by ORDER BY. This field holds this combined sort order.
     SortDescription full_sort_description;
 
-    // No frame info as of yet.
+    WindowFrame frame;
 
     // The window functions that are calculated for this window.
     std::vector<WindowFunctionDescription> window_functions;

src/Interpreters/ExpressionAnalyzer.cpp

@@ -515,6 +515,20 @@ void makeWindowDescription(WindowDescription & desc, const IAST * ast)
     desc.full_sort_description = desc.partition_by;
     desc.full_sort_description.insert(desc.full_sort_description.end(),
         desc.order_by.begin(), desc.order_by.end());
+
+    if (definition.frame.type != WindowFrame::FrameType::Rows)
+    {
+        std::string name = definition.frame.type == WindowFrame::FrameType::Rows
+            ? "ROWS"
+            : definition.frame.type == WindowFrame::FrameType::Groups
+                ? "GROUPS" : "RANGE";
+
+        throw Exception(ErrorCodes::NOT_IMPLEMENTED,
+            "Window frame '{}' is not implemented (while processing '{}')",
+            name, ast->formatForErrorMessage());
+    }
+
+    desc.frame = definition.frame;
 }
 
 void ExpressionAnalyzer::makeWindowDescriptions(ActionsDAGPtr actions)

src/Parsers/ASTWindowDefinition.cpp

@@ -22,6 +22,8 @@ ASTPtr ASTWindowDefinition::clone() const
         result->children.push_back(result->order_by);
     }
 
+    result->frame = frame;
+
     return result;
 }
 
@@ -31,12 +33,12 @@ String ASTWindowDefinition::getID(char) const
 }
 
 void ASTWindowDefinition::formatImpl(const FormatSettings & settings,
-    FormatState & state, FormatStateStacked frame) const
+    FormatState & state, FormatStateStacked format_frame) const
 {
     if (partition_by)
     {
         settings.ostr << "PARTITION BY ";
-        partition_by->formatImpl(settings, state, frame);
+        partition_by->formatImpl(settings, state, format_frame);
     }
 
     if (partition_by && order_by)
@@ -47,7 +49,16 @@ void ASTWindowDefinition::formatImpl(const FormatSettings & settings,
     if (order_by)
     {
         settings.ostr << "ORDER BY ";
-        order_by->formatImpl(settings, state, frame);
+        order_by->formatImpl(settings, state, format_frame);
+    }
+
+    if (!frame.is_default)
+    {
+        const auto name = frame.type == WindowFrame::FrameType::Rows
+            ? "ROWS" : frame.type == WindowFrame::FrameType::Groups
+                ? "GROUPS" : "RANGE";
+
+        settings.ostr << name << " BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW";
     }
 }
 
@@ -56,8 +67,8 @@ std::string ASTWindowDefinition::getDefaultWindowName() const
     WriteBufferFromOwnString ostr;
     FormatSettings settings{ostr, true /* one_line */};
     FormatState state;
-    FormatStateStacked frame;
-    formatImpl(settings, state, frame);
+    FormatStateStacked format_frame;
+    formatImpl(settings, state, format_frame);
     return ostr.str();
 }
 

src/Parsers/ASTWindowDefinition.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <Interpreters/AggregateDescription.h>
+
 #include <Parsers/IAST.h>
 
 
@@ -12,6 +14,8 @@ struct ASTWindowDefinition : public IAST
 
     ASTPtr order_by;
 
+    WindowFrame frame;
+
 
     ASTPtr clone() const override;
 

src/Parsers/ExpressionElementParsers.cpp

@@ -504,6 +504,65 @@ bool ParserWindowReference::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
     return parser_definition.parse(pos, function->window_definition, expected);
 }
 
+static bool tryParseFrameDefinition(ASTWindowDefinition * node, IParser::Pos & pos,
+    Expected & expected)
+{
+    ParserKeyword keyword_rows("ROWS");
+    ParserKeyword keyword_groups("GROUPS");
+    ParserKeyword keyword_range("RANGE");
+
+    if (keyword_rows.ignore(pos, expected))
+    {
+        node->frame.type = WindowFrame::FrameType::Rows;
+    }
+    else if (keyword_groups.ignore(pos, expected))
+    {
+        node->frame.type = WindowFrame::FrameType::Groups;
+    }
+    else if (keyword_range.ignore(pos, expected))
+    {
+        node->frame.type = WindowFrame::FrameType::Range;
+    }
+    else
+    {
+        /* No frame clause. */
+        return true;
+    }
+
+    ParserKeyword keyword_between("BETWEEN");
+    ParserKeyword keyword_unbounded("UNBOUNDED");
+    ParserKeyword keyword_preceding("PRECEDING");
+    ParserKeyword keyword_and("AND");
+    ParserKeyword keyword_current_row("CURRENT ROW");
+
+    if (!keyword_between.ignore(pos, expected))
+    {
+        return false;
+    }
+
+    if (!keyword_unbounded.ignore(pos, expected))
+    {
+        return false;
+    }
+
+    if (!keyword_preceding.ignore(pos, expected))
+    {
+        return false;
+    }
+
+    if (!keyword_and.ignore(pos, expected))
+    {
+        return false;
+    }
+
+    if (!keyword_current_row.ignore(pos, expected))
+    {
+        return false;
+    }
+
+    return true;
+}
+
 bool ParserWindowDefinition::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
 {
     auto result = std::make_shared<ASTWindowDefinition>();
@@ -548,6 +607,12 @@ bool ParserWindowDefinition::parseImpl(Pos & pos, ASTPtr & node, Expected & expe
         }
     }
 
+    if (!tryParseFrameDefinition(result.get(), pos, expected))
+    {
+        /* Broken frame definition. */
+        return false;
+    }
+
     ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
     if (!parser_closing_bracket.ignore(pos, expected))
     {

tests/queries/0_stateless/01591_window_functions.sql

@@ -92,3 +92,15 @@ from numbers(10)
 window
     w1 as (partition by intDiv(number, 3))
 ;
+
+-- ROWS frame
+select
+    sum(number)
+        over (order by number rows between unbounded preceding and current row)
+from numbers(3);
+
+
+select
+    sum(number)
+        over (order by number groups between unbounded preceding and current row)
+from numbers(3);