MySQL 8.0.30
Source Code Documentation
sql_delete.h
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22
23#ifndef SQL_DELETE_INCLUDED
24#define SQL_DELETE_INCLUDED
25
26#include "my_sqlcommand.h"
27#include "my_table_map.h"
28#include "sql/sql_cmd_dml.h" // Sql_cmd_dml
29
30class JOIN;
32class THD;
33struct TABLE_LIST;
34template <typename T>
35class SQL_I_List;
36
37class Sql_cmd_delete final : public Sql_cmd_dml {
38 public:
39 Sql_cmd_delete(bool multitable_arg, SQL_I_List<TABLE_LIST> *delete_tables_arg)
40 : multitable(multitable_arg), delete_tables(delete_tables_arg) {}
41
44 }
45
46 bool is_single_table_plan() const override { return !multitable; }
47
48 bool accept(THD *thd, Select_lex_visitor *visitor) override;
49
50 protected:
51 bool precheck(THD *thd) override;
52 bool check_privileges(THD *thd) override;
53
54 bool prepare_inner(THD *thd) override;
55
56 bool execute_inner(THD *thd) override;
57
58 private:
60
62 /**
63 References to tables that are deleted from in a multitable delete statement.
64 Only used to track such tables from the parser. In preparation and
65 optimization, use the TABLE_LIST::updating property instead.
66 */
68};
69
70/// Find out which of the delete target tables can be deleted from immediately
71/// while scanning. This is used by the old optimizer *after* the plan has been
72/// created. The hypergraph optimizer does not use this function, as it makes
73/// the decision about immediate delete *during* planning, not after planning.
75
76/// Checks if the sql_safe_updates option is enabled, and raises an error and
77/// returns true if the statement is likely to delete or update a large number
78/// of rows. Specifically, it raises an error if there is a full table scan or
79/// full index scan of one of the tables deleted from, and there is no LIMIT
80/// clause.
81bool CheckSqlSafeUpdate(THD *thd, const JOIN *join);
82
83#endif /* SQL_DELETE_INCLUDED */
Definition: sql_optimizer.h:125
Simple intrusive linked list.
Definition: sql_list.h:45
Abstract base class for traversing the Query_block tree.
Definition: select_lex_visitor.h:39
Definition: sql_delete.h:37
SQL_I_List< TABLE_LIST > * delete_tables
References to tables that are deleted from in a multitable delete statement.
Definition: sql_delete.h:67
enum_sql_command sql_command_code() const override
Return the command code for this statement.
Definition: sql_delete.h:42
bool execute_inner(THD *thd) override
Execute a DELETE statement.
Definition: sql_delete.cc:889
bool prepare_inner(THD *thd) override
Prepare a DELETE statement.
Definition: sql_delete.cc:687
bool delete_from_single_table(THD *thd)
Delete a set of rows from a single table.
Definition: sql_delete.cc:203
Sql_cmd_delete(bool multitable_arg, SQL_I_List< TABLE_LIST > *delete_tables_arg)
Definition: sql_delete.h:39
bool precheck(THD *thd) override
Perform a precheck of table privileges for the specific operation.
Definition: sql_delete.cc:151
bool multitable
Definition: sql_delete.h:61
bool check_privileges(THD *thd) override
Check privileges on a prepared statement, called at start of execution of the statement.
Definition: sql_delete.cc:181
bool accept(THD *thd, Select_lex_visitor *visitor) override
Definition: sql_delete.cc:1255
bool is_single_table_plan() const override
Definition: sql_delete.h:46
Definition: sql_cmd_dml.h:34
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:922
enum_sql_command
Definition: my_sqlcommand.h:45
@ SQLCOM_DELETE
Definition: my_sqlcommand.h:53
@ SQLCOM_DELETE_MULTI
Definition: my_sqlcommand.h:120
uint64_t table_map
Definition: my_table_map.h:29
std::string join(Container cont, const std::string &delim)
join elements of an container into a string separated by a delimiter.
Definition: string.h:150
bool CheckSqlSafeUpdate(THD *thd, const JOIN *join)
Checks if the sql_safe_updates option is enabled, and raises an error and returns true if the stateme...
Definition: sql_delete.cc:965
table_map GetImmediateDeleteTables(const JOIN *join, table_map delete_tables)
Find out which of the delete target tables can be deleted from immediately while scanning.
Definition: sql_delete.cc:1259
Definition: table.h:2684