MySQL 8.4.3
Source Code Documentation
sql_delete.h
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23
24#ifndef SQL_DELETE_INCLUDED
25#define SQL_DELETE_INCLUDED
26
27#include "my_sqlcommand.h"
28#include "my_table_map.h"
29#include "sql/sql_cmd_dml.h" // Sql_cmd_dml
30
31class JOIN;
33class THD;
34class Table_ref;
35template <typename T>
36class SQL_I_List;
37
38class Sql_cmd_delete final : public Sql_cmd_dml {
39 public:
40 Sql_cmd_delete(bool multitable_arg, SQL_I_List<Table_ref> *delete_tables_arg)
41 : multitable(multitable_arg), delete_tables(delete_tables_arg) {}
42
45 }
46
47 bool is_single_table_plan() const override { return !multitable; }
48
49 bool accept(THD *thd, Select_lex_visitor *visitor) override;
50
51 protected:
52 bool precheck(THD *thd) override;
53 bool check_privileges(THD *thd) override;
54
55 bool prepare_inner(THD *thd) override;
56
57 bool execute_inner(THD *thd) override;
58
59 private:
61
63 /**
64 References to tables that are deleted from in a multitable delete statement.
65 Only used to track such tables from the parser. In preparation and
66 optimization, use the Table_ref::updating property instead.
67 */
69};
70
71/// Find out which of the delete target tables can be deleted from immediately
72/// while scanning. This is used by the old optimizer *after* the plan has been
73/// created. The hypergraph optimizer does not use this function, as it makes
74/// the decision about immediate delete *during* planning, not after planning.
76
77/// Checks if the sql_safe_updates option is enabled, and raises an error and
78/// returns true if the statement is likely to delete or update a large number
79/// of rows. Specifically, it raises an error if there is a full table scan or
80/// full index scan of one of the tables deleted from, and there is no LIMIT
81/// clause.
82bool CheckSqlSafeUpdate(THD *thd, const JOIN *join);
83
84#endif /* SQL_DELETE_INCLUDED */
Definition: sql_optimizer.h:133
Simple intrusive linked list.
Definition: sql_list.h:47
Abstract base class for traversing the Query_block tree.
Definition: select_lex_visitor.h:40
Definition: sql_delete.h:38
SQL_I_List< Table_ref > * delete_tables
References to tables that are deleted from in a multitable delete statement.
Definition: sql_delete.h:68
enum_sql_command sql_command_code() const override
Return the command code for this statement.
Definition: sql_delete.h:43
bool execute_inner(THD *thd) override
Execute a DELETE statement.
Definition: sql_delete.cc:894
Sql_cmd_delete(bool multitable_arg, SQL_I_List< Table_ref > *delete_tables_arg)
Definition: sql_delete.h:40
bool prepare_inner(THD *thd) override
Prepare a DELETE statement.
Definition: sql_delete.cc:692
bool delete_from_single_table(THD *thd)
Delete a set of rows from a single table.
Definition: sql_delete.cc:204
bool precheck(THD *thd) override
Perform a precheck of table privileges for the specific operation.
Definition: sql_delete.cc:152
bool multitable
Definition: sql_delete.h:62
bool check_privileges(THD *thd) override
Check privileges on a prepared statement, called at start of execution of the statement.
Definition: sql_delete.cc:182
bool accept(THD *thd, Select_lex_visitor *visitor) override
Definition: sql_delete.cc:1260
bool is_single_table_plan() const override
Definition: sql_delete.h:47
Definition: sql_cmd_dml.h:35
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_lexer_thd.h:36
Definition: table.h:2864
enum_sql_command
Definition: my_sqlcommand.h:46
@ SQLCOM_DELETE
Definition: my_sqlcommand.h:54
@ SQLCOM_DELETE_MULTI
Definition: my_sqlcommand.h:121
uint64_t table_map
Definition: my_table_map.h:30
std::string join(const detail::range auto &rng, std::string_view delim)
join elements of a range into a string separated by a delimiter.
Definition: string.h:74
int delete_tables(PFS_engine_table_share_proxy **, unsigned int) noexcept
Definition: pfs_plugin_table_v1_all_empty.cc:39
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:970
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:1264