set @old_debug= @@debug_dbug;
create table t_tmp(a int, b int);
set debug_dbug= "+d,test_pseudo_invisible";
create table t1(a int);
set debug_dbug=@old_debug;
insert into t1 values(1);
desc t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
select a , invisible from t1;
a	invisible
1	9
insert into t1(a, invisible) values(99,99);
ERROR 42S22: Unknown column 'invisible' in 'field list'
insert into t1(invisible) values(99);
ERROR 42S22: Unknown column 'invisible' in 'field list'
insert into t_tmp select a, invisible from t1;
insert into t1 select * from t_tmp;
ERROR 21S01: Column count doesn't match value count at row 1
insert into t1(a,invisible) select * from t_tmp;
ERROR 42S22: Unknown column 'invisible' in 'field list'
select a , invisible from t1;
a	invisible
1	9
insert into t1 values (5), (invisible+1);
select a , invisible from t1;
a	invisible
1	9
5	9
10	9
delete from t1 where a > 1;
update t1 set a = invisible where a=1;
select a , invisible from t1;
a	invisible
9	9
update t1 set a = (select invisible+100 from t1 limit 1) where a=(select a from t1 limit 1);
select a , invisible from t1;
a	invisible
109	9
update t1 set invisible = 23 where a=(select a from t1 limit 1);
ERROR 42S22: Unknown column 'invisible' in 'field list'
update t1 set invisible = 101 where a=(select a from t1 limit 1);
ERROR 42S22: Unknown column 'invisible' in 'field list'
update t1 set invisible = (select invisible+100 from t1 limit 1) where a=(select invisible from t1 limit 1);
ERROR 42S22: Unknown column 'invisible' in 'field list'
select a , invisible from t1;
a	invisible
109	9
set @a=12;
update t1 set invisible = (select @a from dual) where a=(select a from t1 limit 1);
ERROR 42S22: Unknown column 'invisible' in 'field list'
select a , invisible from t1;
a	invisible
109	9
update t1 set invisible = (select invisible+100 from t1 limit 1) where a=(select a from t1 limit 1);
ERROR 42S22: Unknown column 'invisible' in 'field list'
select a , invisible from t1;
a	invisible
109	9
set @a=(select invisible from t1 limit 1);
select @a from dual;
@a
9
alter table t1 add constraint a check (invisible > 2);
ERROR 42S22: Unknown column 'invisible' in 'CHECK'
set debug_dbug= "+d,test_pseudo_invisible";
create table t2(a int, b int as (invisible +2) virtual);
ERROR 42S22: Unknown column 'invisible' in 'GENERATED ALWAYS AS'
create table t2(a int , b int);
insert into t2 values(2,2);
insert into t2 select a, invisible from t1;
set debug_dbug=@old_debug;
select * from t1;
a
109
select invisible ,a from t1;
invisible	a
9	109
drop table t1,t2,t_tmp;
set debug_dbug= "+d,test_completely_invisible";
create table t1(a int);
set debug_dbug=@old_debug;
desc t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
insert into t1 values(1);
select * from t1;
a
1
select invisible ,a from t1;
ERROR 42S22: Unknown column 'invisible' in 'field list'
set debug_dbug= "+d,test_completely_invisible";
select invisible ,a from t1;
invisible	a
9	1
set debug_dbug=@old_debug;
create table t2 (invisible int);
select * from t1 join t2 using (invisible);
ERROR 42S22: Unknown column 'invisible' in 'from clause'
select * from t2 join t1 using (invisible);
ERROR 42S22: Unknown column 'invisible' in 'from clause'
insert t2 values (8),(9);
select * from t1 natural join t2;
a	invisible
1	8
1	9
select * from t2 natural join t1;
invisible	a
8	1
9	1
drop table t1, t2;
set debug_dbug= "+d,test_pseudo_invisible";
create table t1(a int);
set debug_dbug=@old_debug;
desc t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
insert into t1 values(1);
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 change invisible b int;
ERROR 42S22: Unknown column 'invisible' in 't1'
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 modify invisible char;
ERROR 42S22: Unknown column 'invisible' in 't1'
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 drop invisible;
ERROR 42000: Can't DROP COLUMN `invisible`; check that it exists
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 add invisible int;
ERROR 42S21: Duplicate column name 'invisible'
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 add invisible2 int default 2;
select * from t1;
a	invisible2
1	2
select invisible ,a from t1;
invisible	a
9	1
create trigger trg before insert on t1 for each row set new.invisible=1;
ERROR 42S22: Unknown column 'invisible' in 'NEW'
create trigger trg before insert on t1 for each row set @a:=new.invisible;
drop table t1;
set debug_dbug= "+d,test_completely_invisible";
create table t1(a int);
set debug_dbug=@old_debug;
create trigger trg before insert on t1 for each row set new.invisible=1;
ERROR 42S22: Unknown column 'invisible' in 'NEW'
create trigger trg before insert on t1 for each row set @a:=new.invisible;
ERROR 42S22: Unknown column 'invisible' in 'NEW'
set debug_dbug= "+d,test_completely_invisible";
desc t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
insert into t1 values(1);
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 change invisible b int;
ERROR 42S22: Unknown column 'invisible' in 't1'
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 modify invisible char;
ERROR 42S22: Unknown column 'invisible' in 't1'
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 drop invisible;
ERROR 42000: Can't DROP COLUMN `invisible`; check that it exists
select * from t1;
a
1
select invisible ,a from t1;
invisible	a
9	1
ALTER table t1 add invisible int;
select * from t1;
a	invisible
1	NULL
select invisible1, invisible ,a from t1;
invisible1	invisible	a
9	NULL	1
ALTER table t1 add hid int default 2;
select * from t1;
a	invisible	hid
1	NULL	2
select invisible ,a from t1;
invisible	a
NULL	1
drop table t1;
set debug_dbug=@old_debug;
Create table t1( a int default(99) invisible, b int);
insert into t1 values(1);
insert into t1 values(2);
insert into t1 values(3);
insert into t1 values(4);
select * from t1 order by b;
b
1
2
3
4
alter table t1 add index(a);
alter table t1 add index(a,b);
show index from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	a	1	a	A	NULL	NULL	NULL	YES	BTREE		
t1	1	a_2	1	a	A	NULL	NULL	NULL	YES	BTREE		
t1	1	a_2	2	b	A	NULL	NULL	NULL	YES	BTREE		
drop table t1;
set debug_dbug= "+d,test_pseudo_invisible";
Create table t1( a int default(99) invisible, b int);
Create table t2( a int default(99) invisible, b int, unique(invisible));
ERROR 42000: Key column 'invisible' doesn't exist in table
set debug_dbug=@old_debug;
insert into t1 values(1);
insert into t1 values(2);
insert into t1 values(3);
insert into t1 values(4);
select * from t1 order by b;
b
1
2
3
4
select invisible, a, b from t1 order by b;
invisible	a	b
9	99	1
9	99	2
9	99	3
9	99	4
alter table t1 add index(invisible);
ERROR 42000: Key column 'invisible' doesn't exist in table
alter table t1 add index(b,invisible);
ERROR 42000: Key column 'invisible' doesn't exist in table
show index from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
drop table t1;
set debug_dbug= "+d,test_completely_invisible";
Create table t1( a int default(99) invisible, b int);
Create table t2( a int default(99) invisible, b int, unique(invisible));
ERROR 42000: Key column 'invisible' doesn't exist in table
insert into t1 values(1);
insert into t1 values(2);
insert into t1 values(3);
insert into t1 values(4);
select * from t1 order by b;
b
1
2
3
4
select invisible, a, b from t1 order by b;
invisible	a	b
9	99	1
9	99	2
9	99	3
9	99	4
set debug_dbug=@old_debug;
alter table t1 add index(invisible);
ERROR 42000: Key column 'invisible' doesn't exist in table
alter table t1 add index(b,invisible);
ERROR 42000: Key column 'invisible' doesn't exist in table
show index from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
drop table t1;
set debug_dbug= "+d,test_completely_invisible,test_invisible_index";
Create table t1( a int default(99) , b int,c int, index(b));
set debug_dbug=@old_debug;
Show index from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	b	1	b	A	NULL	NULL	NULL	YES	BTREE		
select * from INFORMATION_SCHEMA.STATISTICS where TABLE_SCHEMA ='test' and table_name='t1';
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT	INDEX_COMMENT
def	test	t1	1	test	b	1	b	A	NULL	NULL	NULL	YES	BTREE		
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) DEFAULT 99,
  `b` int(11) DEFAULT NULL,
  `c` int(11) DEFAULT NULL,
  KEY `b` (`b`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
insert into t1 values(1,1,1);
insert into t1 values(2,2,2);
insert into t1 values(3,3,3);
insert into t1 values(4,4,4);
set debug_dbug= "+d,test_completely_invisible,test_invisible_index";
select invisible, a ,b from t1 order by b;
invisible	a	b
9	1	1
9	2	2
9	3	3
9	4	4
explain select * from t1 where invisible =9;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	invisible	invisible	5	const	3	
alter table t1 add x int default 3;
select invisible, a ,b from t1;
invisible	a	b
9	1	1
9	2	2
9	3	3
9	4	4
set debug_dbug=@old_debug;
Show index from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	b	1	b	A	NULL	NULL	NULL	YES	BTREE		
create index a1 on t1(invisible);
ERROR 42000: Key column 'invisible' doesn't exist in table
set debug_dbug= "+d,test_completely_invisible,test_invisible_index";
drop index invisible on t1;
ERROR 42000: Can't DROP INDEX `invisible`; check that it exists
explain select * from t1 where invisible =9;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	invisible	invisible	5	const	3	
create index invisible on t1(c);
explain select * from t1 where invisible =9;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	invisible_2	invisible_2	5	const	3	
show indexes in t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	b	1	b	A	NULL	NULL	NULL	YES	BTREE		
t1	1	invisible	1	c	A	NULL	NULL	NULL	YES	BTREE		
t1	1	invisible_2	1	invisible	A	NULL	NULL	NULL	YES	BTREE		
drop table t1;
set @old_debug= @@debug_dbug;