Simple example of mysql's MERGE storage engine _ MySQL

A simple example of mysql's MERGE storage engine: bitsCN.com

A simple example of mysql's MERGE storage engine

Role: you can merge multiple tables with the same structure into one table.

Supported versions: mysql5.1

Example:

Assume that there are several tables with the same structure: article_0, article_1, article_2, article_3,

-- Table "article_0" DDLCREATE TABLE `article_0` (  `id` bigint(20) NOT NULL,  `subject` varchar(200) NOT NULL,  `content` text NOT NULL,  PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;-- Table "article_1" DDLCREATE TABLE `article_1` (  `id` bigint(20) NOT NULL,  `subject` varchar(200) NOT NULL,  `content` text NOT NULL,  PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;-- Table "article_2" DDLCREATE TABLE `article_2` (  `id` bigint(20) NOT NULL,  `subject` varchar(200) NOT NULL,  `content` text NOT NULL,  PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;-- Table "article_3" DDLCREATE TABLE `article_3` (  `id` bigint(20) NOT NULL,  `subject` varchar(200) NOT NULL,  `content` text NOT NULL,  PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8;

Create a summary table: the structure of article_total is as follows:

-- Table "article_total" DDLCREATE TABLE `article_total` (  `id` bigint(20) NOT NULL,  `subject` varchar(200) NOT NULL,  `content` text NOT NULL,  PRIMARY KEY (`id`)) ENGINE=MRG_MyISAM DEFAULT CHARSET=utf8 UNION=(`article_0`,`article_1`,`article_2`,`article_3`);

The content of the article_total table contains the content of article_0 ', 'article _ 1', 'article _ 2', and 'article _ 3'.

The result of the select * from article_total table is the content of the data merging statements.

Command to modify which sub-tables to merge:

ALTER TABLE article_total  union =(article_0,article_1,article_2,article_3)

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