MySQL 8.0.30
Source Code Documentation
system_view_definition_impl.h
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22
23#ifndef DD_SYSTEM_VIEWS__SYSTEM_VIEW_DEFINITION_IMPL_INCLUDED
24#define DD_SYSTEM_VIEWS__SYSTEM_VIEW_DEFINITION_IMPL_INCLUDED
25
26#include <map>
27#include <memory>
28#include <vector>
29
30#include "sql/dd/string_type.h" // dd::String_type
31#include "sql/dd/types/system_view_definition.h" // dd::System_view_definition
32#include "sql/mysqld.h" // lower_case_table_names
33
34namespace dd {
35namespace system_views {
36
38 public:
39 /**
40 Get view name.
41
42 @return name of the view.
43 */
44 virtual const String_type &view_name() const { return m_view_name; }
45
46 /**
47 Set view name.
48 */
49 virtual void set_view_name(const String_type &name) { m_view_name = name; }
50
51 /**
52 Get collation clause to append to view definition for some
53 view columns based on lower_case_table_names.
54
55 @return Empty string if lctn=0, other wise " COLLATE utf8mb3_tolower_ci".
56 */
58 if (lower_case_table_names != 0) return " COLLATE utf8mb3_tolower_ci";
59 return "";
60 }
61
62 String_type build_ddl_create_view() const override = 0;
63
64 private:
65 // Name of I_S system view;
67};
68
70 public:
71 /**
72 Add a field definition for the SELECT projection.
73 This function can be called more than once. The call will add a new
74 projection to the SELECT command.
75
76 @param field_number Ordinal position of field in the projection list.
77 @param field_name Field name used for the SELECT's projection.
78 @param field_definition Expression representing the projection.
79 @param add_quotes If true, output single quotes around the
80 field_definition.
81 */
82 virtual void add_field(int field_number, const String_type &field_name,
83 const String_type &field_definition,
84 bool add_quotes = false) {
85 // Make sure the field_number and field_name are not added twise.
86 assert(m_field_numbers.find(field_name) == m_field_numbers.end() &&
88
89 // Store the field number.
90 m_field_numbers[field_name] = field_number;
91
92 // Store the field definition expression.
94 if (field_name == "*") {
95 ss << " * ";
96 } else {
97 if (add_quotes) {
98 assert(field_definition.find('\'') == String_type::npos);
99 ss << '\'' << field_definition << '\'';
100 } else
101 ss << field_definition;
102
103 ss << " AS " << field_name;
104 }
105
107 }
108
109 /**
110 Add FROM clause for the SELECT.
111 This function can be called more than once. The clause will be appended to
112 the previous FROM clause string.
113
114 @param from String representing the FROM clause.
115 */
116 virtual void add_from(const String_type &from) {
117 m_from_clauses.push_back(from);
118 }
119
120 /**
121 Add WHERE clause for the SELECT.
122 This function can be called more than once. The clause will be appended to
123 the previous WHERE clause string.
124
125 @param where String representing the WHERE clause.
126 */
127 virtual void add_where(const String_type &where) {
128 m_where_clauses.push_back(where);
129 }
130
131 /**
132 Add CTE expression before SELECT.
133
134 @param cte String representing the CTE expression.
135 */
136 virtual void add_cte_expression(const String_type &cte) {
137 m_cte_expression = cte;
138 }
139
140 /**
141 Indicates that we should add DISTINCT clause to SELECT.
142 */
143 virtual void add_distinct() { m_is_distinct = true; }
144
145 /**
146 Indicates selection of all field (SELECT '*').
147 */
148 virtual void add_star() { m_add_star = true; }
149 /**
150 Get the field ordinal position number for the given field name.
151
152 @param field_name Column name for which the field number is returned.
153
154 @return Integer representing position of column in projection list.
155 */
156 virtual int field_number(const String_type &field_name) const {
157 assert(m_field_numbers.find(field_name) != m_field_numbers.end());
158 return m_field_numbers.find(field_name)->second;
159 }
160
161 /**
162 Build the SELECT query that is used in the CREATE VIEW command.
163
164 @return The SELECT query string.
165 */
168
169 if (!m_cte_expression.empty()) ss << m_cte_expression << "\n ";
170
171 // Make SELECT [DISTINCT]
172 ss << "SELECT " << (m_is_distinct ? "DISTINCT \n" : "\n");
173
174 if (!m_add_star) {
175 // Output view column definitions
176 for (Field_definitions::const_iterator field =
177 m_field_definitions.begin();
178 field != m_field_definitions.end(); ++field) {
179 if (field != m_field_definitions.begin()) ss << ",\n";
180 ss << " " << field->second;
181 }
182 } else
183 ss << "*";
184
185 // Output FROM clauses
186 for (From_clauses::const_iterator from = m_from_clauses.begin();
187 from != m_from_clauses.end(); ++from) {
188 if (from == m_from_clauses.begin()) ss << " FROM ";
189
190 ss << "\n " << *from;
191 }
192
193 // Output WHERE clauses
194 for (Where_clauses::const_iterator where = m_where_clauses.begin();
195 where != m_where_clauses.end(); ++where) {
196 if (where == m_where_clauses.begin()) ss << " WHERE ";
197
198 ss << "\n " << *where;
199 }
200
201 ss << "\n";
202
203 return ss.str();
204 }
205
208 ss << "CREATE OR REPLACE DEFINER=`mysql.infoschema`@`localhost` VIEW "
209 << "information_schema." << view_name() << " AS " + build_select_query();
210
211 return ss.str();
212 }
213
214 private:
215 // Map of field_names and the ordinal position in SELECT projection.
216 typedef std::map<String_type, int> Field_numbers;
217
218 // Map of field ordinal position and their view column definition.
219 typedef std::map<int, String_type> Field_definitions;
220
221 // List of FROM clause definition in the SELECT
222 typedef std::vector<String_type> From_clauses;
223
224 // List of WHERE clause definition in the SELECT
225 typedef std::vector<String_type> Where_clauses;
226
232 bool m_is_distinct{false};
233 bool m_add_star{false};
234};
235
236// This class is unused and kept here for future use.
238 public:
239 /**
240 Get the object for a SELECT definition to be used in the UNION.
241
242 @return The System_view_select_definition_impl&.
243 */
245 m_selects.push_back(
247 return *(m_selects.back().get());
248 }
249
252 bool first_query_block = true;
253 // Union definition must have minimum two SELECTs.
254 assert(m_selects.size() >= 2);
255
256 for (auto &select : m_selects) {
257 if (first_query_block) {
258 ss << "CREATE OR REPLACE DEFINER=`mysql.infoschema`@`localhost` VIEW "
259 << "information_schema." << view_name() << " AS "
260 << "(" << select->build_select_query() << ")";
261 first_query_block = false;
262 } else {
263 ss << " UNION "
264 << "(" << select->build_select_query() << ")";
265 }
266 }
267
268 return ss.str();
269 }
270
271 private:
272 using Select_definition = std::unique_ptr<System_view_select_definition_impl>;
273
274 // Member holds SELECT's used for the UNION
275 std::vector<Select_definition> m_selects;
276};
277
278} // namespace system_views
279} // namespace dd
280
281#endif // DD_SYSTEM_VIEWS__SYSTEM_VIEW_DEFINITION_IMPL_INCLUDED
Definition: system_view_definition_impl.h:37
virtual void set_view_name(const String_type &name)
Set view name.
Definition: system_view_definition_impl.h:49
String_type build_ddl_create_view() const override=0
Build CREATE VIEW DDL statement for the system view.
static const String_type fs_name_collation()
Get collation clause to append to view definition for some view columns based on lower_case_table_nam...
Definition: system_view_definition_impl.h:57
String_type m_view_name
Definition: system_view_definition_impl.h:66
virtual const String_type & view_name() const
Get view name.
Definition: system_view_definition_impl.h:44
Definition: system_view_definition.h:36
Definition: system_view_definition_impl.h:69
virtual int field_number(const String_type &field_name) const
Get the field ordinal position number for the given field name.
Definition: system_view_definition_impl.h:156
virtual void add_field(int field_number, const String_type &field_name, const String_type &field_definition, bool add_quotes=false)
Add a field definition for the SELECT projection.
Definition: system_view_definition_impl.h:82
virtual void add_where(const String_type &where)
Add WHERE clause for the SELECT.
Definition: system_view_definition_impl.h:127
String_type build_select_query() const
Build the SELECT query that is used in the CREATE VIEW command.
Definition: system_view_definition_impl.h:166
virtual void add_from(const String_type &from)
Add FROM clause for the SELECT.
Definition: system_view_definition_impl.h:116
virtual void add_cte_expression(const String_type &cte)
Add CTE expression before SELECT.
Definition: system_view_definition_impl.h:136
Where_clauses m_where_clauses
Definition: system_view_definition_impl.h:230
std::map< String_type, int > Field_numbers
Definition: system_view_definition_impl.h:216
Field_definitions m_field_definitions
Definition: system_view_definition_impl.h:228
virtual void add_star()
Indicates selection of all field (SELECT '*').
Definition: system_view_definition_impl.h:148
virtual void add_distinct()
Indicates that we should add DISTINCT clause to SELECT.
Definition: system_view_definition_impl.h:143
std::map< int, String_type > Field_definitions
Definition: system_view_definition_impl.h:219
From_clauses m_from_clauses
Definition: system_view_definition_impl.h:229
bool m_is_distinct
Definition: system_view_definition_impl.h:232
dd::String_type m_cte_expression
Definition: system_view_definition_impl.h:231
Field_numbers m_field_numbers
Definition: system_view_definition_impl.h:227
String_type build_ddl_create_view() const override
Build CREATE VIEW DDL statement for the system view.
Definition: system_view_definition_impl.h:206
bool m_add_star
Definition: system_view_definition_impl.h:233
std::vector< String_type > From_clauses
Definition: system_view_definition_impl.h:222
std::vector< String_type > Where_clauses
Definition: system_view_definition_impl.h:225
Definition: system_view_definition_impl.h:237
std::unique_ptr< System_view_select_definition_impl > Select_definition
Definition: system_view_definition_impl.h:272
System_view_select_definition_impl & get_query_block()
Get the object for a SELECT definition to be used in the UNION.
Definition: system_view_definition_impl.h:244
std::vector< Select_definition > m_selects
Definition: system_view_definition_impl.h:275
String_type build_ddl_create_view() const override
Build CREATE VIEW DDL statement for the system view.
Definition: system_view_definition_impl.h:250
uint lower_case_table_names
Definition: mysqld.cc:1311
static char * where
Definition: mysqldump.cc:136
The version of the current data dictionary table definitions.
Definition: dictionary_client.h:42
Char_stringstream_template< String_type_allocator > Stringstream_type
Instantiation of std::basic_stringstream with the same allocator as String_type.
Definition: string_type.h:71
Char_string_template< String_type_allocator > String_type
Definition: string_type.h:50
case opt name
Definition: sslopt-case.h:32