根据表的某个字段拆分大表成多个小表，以前做的，留作笔记

  用的工具是：Navicat for MySQL，在其中定义了几个存储过程。要拆分的大表：tcc_method_coverage，其中有一个字段名：table_name，我们就是要根据table_name的值，将tcc_method_coverage表的数据进行分组，譬如，table_name的值为abc，那么，就将tcc_method_coverage表中所有table_name值为abc的记录全部“挪移”到一张新表abc_mc，并且，给这张新表建立索引。

总共5个存储过程：

总执行入口(transfer_method_data):

 

begin
    declare v_table_name varchar(200);
    declare flag int default 0;

    declare curl cursor for select DISTINCT table_name from tcc_method_coverage;

    declare continue handler for sqlstate '02000' set flag = 1;

    open curl;

    fetch curl into v_table_name;

    WHILE(flag != 1) DO
        call create_table_if_not_exist(CONCAT(v_table_name, '_mc'));
        call drop_table_index(CONCAT(v_table_name, '_mc'));
        call insert_data_to_table(CONCAT(v_table_name, '_mc'), v_table_name);
        call create_table_index(CONCAT(v_table_name, '_mc'));
        fetch curl into v_table_name;
    end WHILE;

    close curl;

end

create_table_if_not_exist:

参数类型是：

`new_table_name` varchar(200)

BEGIN
    declare v_create_table_sql varchar(1000);

    set @v_create_table_sql = CONCAT('create table if not exists ', new_table_name, ' (
        id int(11) NOT NULL AUTO_INCREMENT,
                name varchar(500) DEFAULT NULL,
                class_coverage double DEFAULT NULL,
                class_ratio varchar(100) DEFAULT NULL,
                method_coverage double DEFAULT NULL,
                method_ratio varchar(100) DEFAULT NULL,
                block_coverage double DEFAULT NULL,
                block_ratio varchar(100) DEFAULT NULL,
                line_coverage double DEFAULT NULL,
                line_ratio varchar(100) DEFAULT NULL,
                class_fail char(1) DEFAULT NULL,
                method_fail char(1) DEFAULT NULL,
                block_fail char(1) DEFAULT NULL,
                line_fail char(1) DEFAULT NULL,
                class_id int(11) DEFAULT NULL,
                table_name varchar(200) DEFAULT NULL,
                dateTime datetime DEFAULT NULL,
                primary key(id)
                ) ENGINE=InnoDB DEFAULT CHARSET=gbk');


    #select v_create_table_sql;
    PREPARE stmt from @v_create_table_sql;
    EXECUTE stmt;

END

drop_table_index:

 

参数类型是：

`new_table_name` varchar(200)

 insert_data_to_table：

参数类型是：

 

`new_table_name` varchar(200),`table_name` varchar(200)

 

BEGIN
    declare v_insert_sql varchar(1000);

    set @v_insert_sql = CONCAT('insert into ', new_table_name, ' (
                name,
                class_coverage,
                class_ratio,
                method_coverage,
                method_ratio,
                block_coverage,
                block_ratio,
                line_coverage,
                line_ratio,
                class_fail,
                method_fail,
                block_fail,
                line_fail,
                class_id,
                table_name,
                dateTime
                ) SELECT name,
                class_coverage,
                class_ratio,
                method_coverage,
                method_ratio,
                block_coverage,
                block_ratio,
                line_coverage,
                line_ratio,
                class_fail,
                method_fail,
                block_fail,
                line_fail,
                class_id,
                table_name,
                dateTime
                FROM tcc_method_coverage
                WHERE table_name = \'', table_name, '\'');

    PREPARE stmt from @v_insert_sql;
    EXECUTE stmt;

END

create_table_index：

参数类型是：

 

`new_table_name` varchar(200)

 

BEGIN
    declare v_index_name varchar(500);
    declare v_table_column varchar(500);
    declare v_create_index_sql varchar(500);

    set v_index_name = CONCAT(new_table_name, '_cid');
    set v_table_column = CONCAT(new_table_name, '(', 'class_id', ')');

    #create index
    set @v_create_index_sql = CONCAT('create index ', v_index_name, ' on ', v_table_column);

    prepare stmt from @v_create_index_sql;
    EXECUTE stmt;

END

也是参考了网上的一些资料，然后自己跌跌撞撞地写出来的mysql存储过程代码，记录在此，权当一份记忆（毕竟，咱也稍微写过一下存储过程，呵呵）。当然拆表的事情也可以通过java+jdbc去做。不过，在这里，的确是存储过程更直接方便一些。