DeveelDB  20151217
complete SQL database system, primarly developed for .NET/Mono frameworks
GroupByNode.cs
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16 
17 using System;
18 using System.Collections.Generic;
19 using System.Linq;
20 
21 namespace Deveel.Data.Sql.Parser {
25  class GroupByNode : SqlNode {
26  internal GroupByNode() {
27  }
28 
32  public IEnumerable<IExpressionNode> GroupExpressions { get; private set; }
33 
37  public IExpressionNode HavingExpression { get; private set; }
38 
40  protected override ISqlNode OnChildNode(ISqlNode node) {
41  if (node.NodeName == "sql_expression_list") {
42  GetGroupExpressions(node);
43  } else if (node.NodeName == "having_clause_opt") {
44  HavingExpression = node.ChildNodes.FirstOrDefault() as IExpressionNode;
45  }
46 
47  return base.OnChildNode(node);
48  }
49 
50  private void GetGroupExpressions(ISqlNode node) {
51  var exps = new List<IExpressionNode>();
52  foreach (var childNode in node.ChildNodes) {
53  if (childNode is IExpressionNode)
54  exps.Add((IExpressionNode) childNode);
55  }
56 
57  GroupExpressions = exps.ToArray();
58  }
59  }
60 }
Defines the contract for nodes in an AST model for a SQL grammar analysis and parsing.
Definition: ISqlNode.cs:25
string NodeName
Gets the name of the node analyzed from the parser.
Definition: ISqlNode.cs:29
override ISqlNode OnChildNode(ISqlNode node)
During the initialization of the node from the parser, this method is called for every child node add...
Definition: GroupByNode.cs:40
IEnumerable< ISqlNode > ChildNodes
Gets a read-only enumeration of the children nodes, if any.
Definition: ISqlNode.cs:39
void GetGroupExpressions(ISqlNode node)
Definition: GroupByNode.cs:50
A node that describes the GROUP BY clause in a SQL query.
Definition: GroupByNode.cs:25
This interface acts like a marker that indicates if a ISqlNode represents a SQL expression.
The default implementation of ISqlNode, that is a node in the text analysis parsing of SQL commands...
Definition: SqlNode.cs:32