1 | #pragma once |
2 | |
3 | #include <Parsers/IAST.h> |
4 | #include <Parsers/IParser.h> |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | /// TODO: Quite messy. |
10 | class ASTQueryWithOnCluster |
11 | { |
12 | public: |
13 | using Pos = IParser::Pos; |
14 | |
15 | /// Should be parsed from ON CLUSTER <cluster> clause |
16 | String cluster; |
17 | |
18 | /// new_database should be used by queries that refer to default db |
19 | /// and default_database is specified for remote server |
20 | virtual ASTPtr getRewrittenASTWithoutOnCluster(const std::string & new_database = {}) const = 0; |
21 | |
22 | /// Returns a query prepared for execution on remote server |
23 | std::string getRewrittenQueryWithoutOnCluster(const std::string & new_database = {}) const; |
24 | |
25 | void formatOnCluster(const IAST::FormatSettings & settings) const; |
26 | |
27 | /// Parses " CLUSTER [cluster|'cluster'] " clause |
28 | static bool parse(Pos & pos, std::string & cluster_str, Expected & expected); |
29 | |
30 | virtual ~ASTQueryWithOnCluster() = default; |
31 | ASTQueryWithOnCluster() = default; |
32 | ASTQueryWithOnCluster(const ASTQueryWithOnCluster &) = default; |
33 | ASTQueryWithOnCluster & operator=(const ASTQueryWithOnCluster &) = default; |
34 | |
35 | protected: |
36 | template <typename T> |
37 | static ASTPtr removeOnCluster(ASTPtr query_ptr, const std::string & new_database) |
38 | { |
39 | T & query = static_cast<T &>(*query_ptr); |
40 | |
41 | query.cluster.clear(); |
42 | if (query.database.empty()) |
43 | query.database = new_database; |
44 | |
45 | return query_ptr; |
46 | } |
47 | |
48 | template <typename T> |
49 | static ASTPtr removeOnCluster(ASTPtr query_ptr) |
50 | { |
51 | T & query = static_cast<T &>(*query_ptr); |
52 | query.cluster.clear(); |
53 | return query_ptr; |
54 | } |
55 | }; |
56 | |
57 | } |
58 | |