mariadb/mysql-test/suite/innodb/t/innodb-fk-warnings.test
Aleksey Midenkov a518e1dd42 MDEV-20865 Store foreign key info in TABLE_SHARE
1. Access foreign keys via TABLE_SHARE::foreign_keys and
   TABLE_SHARE::referenced_keys;

   foreign_keys and referenced_keys are lists in TABLE_SHARE.

2. Remove handler FK interface:

   - get_foreign_key_list()
   - get_parent_foreign_key_list()
   - referenced_by_foreign_key()

3. Invalidate referenced shares on:

   - RENAME TABLE
   - DROP TABLE
   - RENAME COLUMN
   - ADD FOREIGN KEY

   When foreign table is created or altered by the above operations
   all referenced shares are closed. This blocks the operation while
   any referenced shares are used (when at least one its TABLE
   instance is locked).

4. Update referenced shares on:

   - CREATE TABLE

   On CREATE TABLE add items to referenced_keys of referenced
   shares. States of referenced shares are restored in case of errors.

5. Invalidate foreign shares on:

   - RENAME TABLE
   - RENAME COLUMN

   The above-mentioned blocking takes effect.

6. Check foreign/referenced shares consistency on:

   - CHECK TABLE

7. Temporary change until MDEV-21051:

   InnoDB fill foreign key info at handler open().

FOREIGN_KEY_INFO is refactored to FK_info holding Lex_cstring.

On first TABLE open FK_info is loaded from storage engine into
TABLE_SHARE. All referenced shares (if any exists) are closed. This
leads to blocking of first time foreign table open while referenced
tables are used.

MDEV-21311 Converge Foreign_key and supplemental generated Key together

mysql_prepare_create_table() does data validation and such utilities
as automatic name generation. But it does that only for indexes and
ignores Foreign_key objects. Now as Foreign_key data needs to be
stored in FRM files as well this processing must be done for it like
for any other Key objects.

Replace Key::FOREIGN_KEY type with Key::foreign flag of type
Key::MULTIPLE and Key::generated set to true. Construct one object
with Key::foreign == true instead of two objects of type
Key::FOREIGN_KEY and Key::MULTIPLE.

MDEV-21051 datadict refactorings

- Move read_extra2() to datadict.cc
- Refactored extra2_fields to Extra2_info
- build_frm_image() readability

MDEV-21051 build_table_shadow_filename() refactoring

mysql_prepare_alter_table() leaks fixes

MDEV-21051 amend system tables locking restriction

Table mysql.help_relation has foreign key to mysql.help_keyword. On
bootstrap when help_relation is opened, it preopens help_keyword for
READ and fails in lock_tables_check().

If system table is opened for write then fk references are opened for
write.

Related to: Bug#25422, WL#3984
Tests: main.lock

MDEV-21051 Store and read foreign key info into/from FRM files

1. Introduce Foreign_key_io class which creates/parses binary stream
containing foreign key structures. Referenced tables store there only
hints about foreign tables (their db and name), they restore full info
from the corresponding tables.

Foreign_key_io is stored under new EXTRA2_FOREIGN_KEY_INFO field in
extra2 section of FRM file.

2. Modify mysql_prepare_create_table() to generate names for foreign
keys. Until InnoDB storage of foreign keys is removed, FK names must
be unique across the database: the FK name must be based on table
name.

3. Keep stored data in sync on DDL changes. Referenced tables update
their foreign hints after following operations on foreign tables:

  - RENAME TABLE
  - DROP TABLE
  - CREATE TABLE
  - ADD FOREIGN KEY
  - DROP FOREIGN KEY

Foreign tables update their foreign info after following operations on
referenced tables:

  - RENAME TABLE
  - RENAME COLUMN

4. To achieve 3. there must be ability to rewrite extra2 section of
FRM file without full reparse. FRM binary is built from primary
structures like HA_CREATE_INFO and cannot be built from TABLE_SHARE.

Use shadow write and rename like fast_alter_partition_table()
does. Shadow FRM is new FRM file that replaces the old one.

CREATE TABLE workflow:

  1. Foreign_key is constructed in parser, placed into
     alter_info->key_list;

  2. mysql_prepare_create_table() translates them to FK_info, assigns
     foreign_id if needed;

  3. build_frm_image() writes two FK_info lists into FRM's extra2
     section, for referenced keys it stores only table names (hints);

  4. init_from_binary_frm_image() parses extra2 section and fills
     foreign_keys and referenced_keys of TABLE_SHARE.

     It restores referenced_keys by reading hint list of table names,
     opening corresponding shares and restoring FK_info from their
     foreign_keys. Hints resolution is done only when initializing
     non-temporary shares. Usually temporary share has different
     (temporary) name and it is impossible to resolve foreign keys by
     that name (as we identify them by both foreign and referenced
     table names). Another not unimportant reason is performance: this
     saves spare share acquisitions.

ALTER TABLE workflow:

  1. Foreign_key is constructed in parser, placed into
     alter_info->key_list;

  2. mysql_prepare_alter_table() prepares action lists and share list
     of foreigns/references;

  3. mysql_prepare_alter_table() locks list of foreigns/references by
     MDL_INTENTION_EXCLUSIVE, acquires shares;

  4. prepare_create_table() converts key_list into FK_list, assigns
     foreign_id;

  5. shadow FRM of altered table is created;

  6. data is copied;

  7. altered table is locked by MDL_EXCLUSIVE;

  8. fk_handle_alter() processes action lists, creates FK backups,
     modifies shares, writes shadow FRMs;

  9. altered table is closed;

  10. shadow FRMs are installed;

  11. altered table is renamed, FRM backup deleted;

  12. (TBD in MDEV-21053) shadow FRMs installation log closed, backups
      deleted;

On FK backup system:

In case of failed DDL operation all shares that was modified must be
restored into original state. This is done by FK_ddl_backup (CREATE,
DROP), FK_rename_backup (RENAME), FK_alter_backup (ALTER).

On STL usage:

STL is used for utility not performance-critical algorithms, core
structures hold native List. A wrapper was made to convert STL
exception into bool error status or NULL value.

MDEV-20865 fk_check_consistency() in CHECK TABLE

Self-refs fix

Test table_flags fix: "debug" deviation is now gone.

FIXMEs: +16 -1
2025-09-02 13:24:36 +03:00

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Text

--source include/have_innodb.inc
#
# MDEV-8524: Improve error messaging when there is duplicate key or foreign key names
#
CREATE TABLE t1 (
id int(11) NOT NULL PRIMARY KEY,
a int(11) NOT NULL,
b int(11) NOT NULL,
c int not null,
CONSTRAINT test FOREIGN KEY (b) REFERENCES t1 (id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE t2 (
id int(11) NOT NULL PRIMARY KEY,
a int(11) NOT NULL,
b int(11) NOT NULL,
c int not null,
CONSTRAINT mytest FOREIGN KEY (c) REFERENCES t1(id),
CONSTRAINT test FOREIGN KEY (b) REFERENCES t2 (id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
show warnings;
drop table t2,t1;
#
# MDEV-6697: Improve foreign keys warnings/errors
#
#
# No index for referenced columns
#
create table t1(a int) engine=innodb;
--error ER_FK_NO_INDEX_PARENT
create table t2(a int, constraint a foreign key a (a) references t1(a)) engine=innodb;
show warnings;
drop table t1;
create table t1(a int unique, b int) engine=innodb;
--error ER_FK_NO_INDEX_PARENT
create table t2(a int, b int, foreign key (a) references t1(a), foreign key (b) references t1(b)) engine=innodb;
show warnings;
drop table t1;
create table t1(a int not null primary key, b int) engine=innodb;
--error ER_DUP_CONSTRAINT_NAME
create table t2(a int, b int, constraint a foreign key a (a) references t1(a),
constraint a foreign key a (a) references t1(b)) engine=innodb;
show warnings;
create table t2(a int, b int, constraint a foreign key a (a) references t1(a)) engine=innodb;
--error ER_CANT_CREATE_TABLE
alter table t2 add constraint b foreign key (b) references t2(b);
show warnings;
drop table t2, t1;
#
# Referenced table does not exists
#
create table t1 (f1 integer primary key) engine=innodb;
--error ER_NO_SUCH_TABLE
alter table t1 add constraint c1 foreign key (f1) references t11(f1);
show warnings;
drop table t1;
#
# Foreign key on temporal tables
#
create temporary table t1(a int not null primary key, b int, key(b)) engine=innodb;
# remove echoes and uncomment the commented when MDEV-8569 is fixed
--echo create temporary table t2(a int, foreign key(a) references t1(a)) engine=innodb;
--echo ERROR HY000: Can't create table `test`.`t2` (errno: 150 "Foreign key constraint is incorrectly formed")
--echo show warnings;
--echo Level Code Message
--echo Warning 150 Create table `mysqld.1`.`t2` with foreign key constraint failed. Referenced table `mysqld.1`.`t1` not found in the data dictionary close to foreign key(a) references t1(a)) engine=innodb.
--echo Error 1005 Can't create table `test`.`t2` (errno: 150 "Foreign key constraint is incorrectly formed")
--echo Warning 1215 Cannot add foreign key constraint
--echo alter table t1 add foreign key(b) references t1(a);
--echo ERROR HY000: Can't create table `test`.`#sql-temporary` (errno: 150 "Foreign key constraint is incorrectly formed")
--echo show warnings;
--echo Level Code Message
--echo Warning 150 Alter table `mysqld.1`.`t1` with foreign key constraint failed. Referenced table `mysqld.1`.`t1` not found in the data dictionary close to foreign key(b) references t1(a).
--echo Error 1005 Can't create table `test`.`#sql-temporary` (errno: 150 "Foreign key constraint is incorrectly formed")
--echo Warning 1215 Cannot add foreign key constraint
--error ER_NO_SUCH_TABLE
create temporary table t2(a int, foreign key(a) references t1(a)) engine=innodb;
show warnings;
--error ER_CANT_CREATE_TABLE
alter table t1 add foreign key(b) references t1(a);
show warnings;
drop table t1;
#
# Column numbers do not match
#
create table t1(a int not null primary key, b int, key(b)) engine=innodb;
--error 1239
alter table t1 add foreign key(a,b) references t1(a);
show warnings;
drop table t1;
create table t1(a int not null primary key, b int, key(b)) engine=innodb;
--error 1239
alter table t1 add foreign key(a) references t1(a,b);
show warnings;
drop table t1;
#
# ON UPDATE/DELETE SET NULL on NOT NULL column
#
create table t1 (f1 integer not null primary key) engine=innodb;
--error ER_CANT_CREATE_TABLE
alter table t1 add constraint c1 foreign key (f1) references t1(f1) on update set null;
show warnings;
--error ER_CANT_CREATE_TABLE
create table t2(a int not null, foreign key(a) references t1(f1) on delete set null) engine=innodb;
show warnings;
drop table t1;
#
# Incorrect types
#
create table t1 (id int not null primary key, f1 int, f2 int, key(f1)) engine=innodb;
--error ER_WRONG_FK_DEF
create table t2(a char(20), key(a), foreign key(a) references t1(f1)) engine=innodb;
show warnings;
drop table t1;