How to copy MySQL table structure to table in memory?
How to create a table in memory which is identical to "regular" table? I want a copy without indexes and constraints. Pure SQL (no external tools).
This works (however indexes are created):
create table t_copy (like t_original)
This doesn't:
create table t_copy (like t_origin开发者_如何学Pythonal) engine=memory
CREATE TABLE t_copy ENGINE=MEMORY SELECT * FROM t_original;
I actually tried it, it works !!!
mysql> show create table queue\G
*************************** 1. row ***************************
Table: queue
Create Table: CREATE TABLE `queue` (
`ndx` int(11) NOT NULL AUTO_INCREMENT,
`folderid` int(11) NOT NULL,
PRIMARY KEY (`ndx`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=latin1
1 row in set (0.02 sec)
mysql> create table queue_memory engine=MEMORY as select * from queue;
Query OK, 0 rows affected (0.05 sec)<BR>
Records: 0 Duplicates: 0 Warnings: 0<BR>
lwdba@localhost (DB test) :: show create table queue_memory\G
*************************** 1. row ***************************
Table: queue_memory
Create Table: CREATE TABLE `queue_memory` (
`ndx` int(11) NOT NULL DEFAULT '0',
`folderid` int(11) NOT NULL
) ENGINE=MEMORY DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
Give it a try !!!
This should get you an empty table without any indexes.
create table t_copy
select *
from t_original
where 0
To create an in-memory table with the same structure AND indexes as the first table, try:
create table t_copy like t_original;
alter table t_copy engine=mem;
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