1 | #pragma once |
2 | |
3 | #include <Interpreters/ColumnNamesContext.h> |
4 | #include <Interpreters/InDepthNodeVisitor.h> |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | namespace ErrorCodes |
10 | { |
11 | extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH; |
12 | } |
13 | |
14 | class ASTIdentifier; |
15 | class ASTFunction; |
16 | class ASTSelectQuery; |
17 | struct ASTTablesInSelectQueryElement; |
18 | struct ASTArrayJoin; |
19 | struct ASTTableExpression; |
20 | |
21 | class RequiredSourceColumnsMatcher |
22 | { |
23 | public: |
24 | using Visitor = ConstInDepthNodeVisitor<RequiredSourceColumnsMatcher, false>; |
25 | using Data = ColumnNamesContext; |
26 | |
27 | static bool needChildVisit(const ASTPtr & node, const ASTPtr & child); |
28 | static void visit(const ASTPtr & ast, Data & data); |
29 | |
30 | private: |
31 | static void visit(const ASTIdentifier & node, const ASTPtr &, Data & data); |
32 | static void visit(const ASTFunction & node, const ASTPtr &, Data & data); |
33 | static void visit(const ASTTablesInSelectQueryElement & node, const ASTPtr &, Data & data); |
34 | static void visit(const ASTTableExpression & node, const ASTPtr &, Data & data); |
35 | static void visit(const ASTArrayJoin & node, const ASTPtr &, Data & data); |
36 | static void visit(const ASTSelectQuery & select, const ASTPtr &, Data & data); |
37 | }; |
38 | |
39 | /// Extracts all the information about columns and tables from ASTSelectQuery block into ColumnNamesContext object. |
40 | /// It doesn't use anything but AST. It visits nodes from bottom to top except ASTFunction content to get aliases in right manner. |
41 | /// @note There's some ambiguousness with nested columns names that can't be solved without schema. |
42 | using RequiredSourceColumnsVisitor = RequiredSourceColumnsMatcher::Visitor; |
43 | |
44 | } |
45 | |