记录一次如何查询mysql分库分表数据-编程知识

一、前言

本次查询是在未知如何分库分表的情况下，对表数据进行查询，其中有的字段为JSON结构。需要提取JSON中某个字段的内容。

二、查询步骤

1、第一方式是将所有分表数据进行union all

select  * from  apporder.ord_shopping_order
union all 
select  * from  apporder.ord_shopping_order_2
union all 
select  * from  apporder.ord_shopping_order_3
union all 
select  * from  apporder.ord_shopping_order_4
union all 
select  * from  apporder.ord_shopping_order_5
union all 
select  * from  apporder.ord_shopping_order_6
union all 
select  * from  apporder.ord_shopping_order_7
union all 
select  * from  apporder.ord_shopping_order_8
union all 
select  * from  apporder.ord_shopping_order_9
union all 
select  * from  apporder.ord_shopping_order_10
union all 
select  * from  apporder.ord_shopping_order_11
union all 
select  * from  apporder.ord_shopping_order_12
union all 
select  * from  apporder.ord_shopping_order_13
union all 
select  * from  apporder.ord_shopping_order_14
union all 
select  * from  apporder.ord_shopping_order_15
union all 
select  * from  apporder.ord_shopping_order_16
union all 
select  * from  apporder.ord_shopping_order_17
union all 
select  * from  apporder.ord_shopping_order_18
union all 
select  * from  apporder.ord_shopping_order_19
union all 
select  * from  apporder.ord_shopping_order_20
union all 
select  * from  apporder.ord_shopping_order_21
union all 
select  * from  apporder.ord_shopping_order_22
union all 
select  * from  apporder.ord_shopping_order_23
union all 
select  * from  apporder.ord_shopping_order_24
union all 
select  * from  apporder.ord_shopping_order_25
union all 
select  * from  apporder.ord_shopping_order_26
union all 
select  * from  apporder.ord_shopping_order_27
union all 
select  * from  apporder.ord_shopping_order_28
union all 
select  * from  apporder.ord_shopping_order_29
union all 
select  * from  apporder.ord_shopping_order_30
union all 
select  * from  apporder.ord_shopping_order_31
union all 
select  * from  apporder.ord_shopping_order_32
union all 
select  * from  apporder.ord_shopping_order_33
union all 
select  * from  apporder.ord_shopping_order_34
union all 
select  * from  apporder.ord_shopping_order_35
union all 
select  * from  apporder.ord_shopping_order_36
union all 
select  * from  apporder.ord_shopping_order_37
union all 
select  * from  apporder.ord_shopping_order_38
union all 
select  * from  apporder.ord_shopping_order_39
union all 
select  * from  apporder.ord_shopping_order_40
union all 
select  * from  apporder.ord_shopping_order_41
union all 
select  * from  apporder.ord_shopping_order_42
union all 
select  * from  apporder.ord_shopping_order_43
union all 
select  * from  apporder.ord_shopping_order_44
union all 
select  * from  apporder.ord_shopping_order_45
union all 
select  * from  apporder.ord_shopping_order_46
union all 
select  * from  apporder.ord_shopping_order_47
union all 
select  * from  apporder.ord_shopping_order_48
union all 
select  * from  apporder.ord_shopping_order_49
union all 
select  * from  apporder.ord_shopping_order_50
union all 
select  * from  apporder.ord_shopping_order_51
union all 
select  * from  apporder.ord_shopping_order_52
union all 
select  * from  apporder.ord_shopping_order_53
union all 
select  * from  apporder.ord_shopping_order_54
union all 
select  * from  apporder.ord_shopping_order_55
union all 
select  * from  apporder.ord_shopping_order_56
union all 
select  * from  apporder.ord_shopping_order_57
union all 
select  * from  apporder.ord_shopping_order_58
union all 
select  * from  apporder.ord_shopping_order_59
union all 
select  * from  apporder.ord_shopping_order_60
union all 
select  * from  apporder.ord_shopping_order_61
union all 
select  * from  apporder.ord_shopping_order_62
union all 
select  * from  apporder.ord_shopping_order_63;

2、第二种方式是创建一个存储过程，方便以后更快速查询

先建一个表结构与分表一样的表 ord_shopping_procedure

create table ord_shopping_procedure as select * from ord_shopping_order_2;

create table ord_shopping_procedure as  select  * from  ord_shopping_order_2

然后创建存储过程

CREATE DEFINER=`root`@`%` PROCEDURE `apporder`.`ord_shopping`()
begin
truncate table ord_shopping_procedure;
insert into   ord_shopping_procedure
select  * from  apporder.ord_shopping_order
union all 
select  * from  apporder.ord_shopping_order_2
union all 
select  * from  apporder.ord_shopping_order_3
union all 
select  * from  apporder.ord_shopping_order_4
union all 
select  * from  apporder.ord_shopping_order_5
union all 
select  * from  apporder.ord_shopping_order_6
union all 
select  * from  apporder.ord_shopping_order_7
union all 
select  * from  apporder.ord_shopping_order_8
union all 
select  * from  apporder.ord_shopping_order_9
union all 
select  * from  apporder.ord_shopping_order_10
union all 
select  * from  apporder.ord_shopping_order_11
union all 
select  * from  apporder.ord_shopping_order_12
union all 
select  * from  apporder.ord_shopping_order_13
union all 
select  * from  apporder.ord_shopping_order_14
union all 
select  * from  apporder.ord_shopping_order_15
union all 
select  * from  apporder.ord_shopping_order_16
union all 
select  * from  apporder.ord_shopping_order_17
union all 
select  * from  apporder.ord_shopping_order_18
union all 
select  * from  apporder.ord_shopping_order_19
union all 
select  * from  apporder.ord_shopping_order_20
union all 
select  * from  apporder.ord_shopping_order_21
union all 
select  * from  apporder.ord_shopping_order_22
union all 
select  * from  apporder.ord_shopping_order_23
union all 
select  * from  apporder.ord_shopping_order_24
union all 
select  * from  apporder.ord_shopping_order_25
union all 
select  * from  apporder.ord_shopping_order_26
union all 
select  * from  apporder.ord_shopping_order_27
union all 
select  * from  apporder.ord_shopping_order_28
union all 
select  * from  apporder.ord_shopping_order_29
union all 
select  * from  apporder.ord_shopping_order_30
union all 
select  * from  apporder.ord_shopping_order_31
union all 
select  * from  apporder.ord_shopping_order_32
union all 
select  * from  apporder.ord_shopping_order_33
union all 
select  * from  apporder.ord_shopping_order_34
union all 
select  * from  apporder.ord_shopping_order_35
union all 
select  * from  apporder.ord_shopping_order_36
union all 
select  * from  apporder.ord_shopping_order_37
union all 
select  * from  apporder.ord_shopping_order_38
union all 
select  * from  apporder.ord_shopping_order_39
union all 
select  * from  apporder.ord_shopping_order_40
union all 
select  * from  apporder.ord_shopping_order_41
union all 
select  * from  apporder.ord_shopping_order_42
union all 
select  * from  apporder.ord_shopping_order_43
union all 
select  * from  apporder.ord_shopping_order_44
union all 
select  * from  apporder.ord_shopping_order_45
union all 
select  * from  apporder.ord_shopping_order_46
union all 
select  * from  apporder.ord_shopping_order_47
union all 
select  * from  apporder.ord_shopping_order_48
union all 
select  * from  apporder.ord_shopping_order_49
union all 
select  * from  apporder.ord_shopping_order_50
union all 
select  * from  apporder.ord_shopping_order_51
union all 
select  * from  apporder.ord_shopping_order_52
union all 
select  * from  apporder.ord_shopping_order_53
union all 
select  * from  apporder.ord_shopping_order_54
union all 
select  * from  apporder.ord_shopping_order_55
union all 
select  * from  apporder.ord_shopping_order_56
union all 
select  * from  apporder.ord_shopping_order_57
union all 
select  * from  apporder.ord_shopping_order_58
union all 
select  * from  apporder.ord_shopping_order_59
union all 
select  * from  apporder.ord_shopping_order_60
union all 
select  * from  apporder.ord_shopping_order_61
union all 
select  * from  apporder.ord_shopping_order_62
union all 
select  * from  apporder.ord_shopping_order_63;truncate table ord_shopping;
insert into   ord_shopping
select t.*, JSON_EXTRACT(t.json, '$.skuName') as sku_name from  (
select id,order_type,order_mode,user_id,user_name,trade_no,state,total_amount, pay_amount pay_time ,
ou_name ,mobile  ,create_time, sale_amount, JSON_EXTRACT(item_abstract_json, '$[0]') as json,store_ou_code,store_name
,mch_ou_code,mch_name
from  ord_shopping_procedure ) t;END;

由于表中存在JSON字段，同时我们再查询表是应查询需要的字段即可

所以这一段是重点

truncate table ord_shopping;
insert into ord_shopping
select t.*, JSON_EXTRACT(t.json, '$.skuName') as sku_name from (
select id,order_type,order_mode,user_id,user_name,trade_no,state,total_amount, pay_amount pay_time ,
ou_name ,mobile ,create_time, sale_amount, JSON_EXTRACT(item_abstract_json, '$[0]') as json,store_ou_code,store_name
,mch_ou_code,mch_name
from ord_shopping_procedure ) t;

truncate table ord_shopping;
insert into   ord_shopping
select t.*, JSON_EXTRACT(t.json, '$.skuName') as sku_name from  (
select id,order_type,order_mode,user_id,user_name,trade_no,state,total_amount, pay_amount pay_time ,
ou_name ,mobile  ,create_time, sale_amount, JSON_EXTRACT(item_abstract_json, '$[0]') as json,store_ou_code,store_name
,mch_ou_code,mch_name
from  ord_shopping_procedure ) t;

JSON_EXTRACT(item_abstract_json, '$[0]') as json

表示item_abstract_json这字段存储的JSON字符串数组，我们把下标为0的取出来，

样例数据是这样的

[{"id": 1059,"productType": 1,"productTypeSub": null,"skuName": "L’Oréal 欧莱雅男士锐能抗皱紧致洁面膏","skuId": 194538,"skuCode": "200015112056194538","thirdCode": "C023338","isGift": 0,"scale": null,"unit": null,"brandId": 1707,"storeOuCode": "1043002001","number": 1,"specs": "规格:100ML  ","cls1StaId": 1316,"cls2StaId": 16831,"cls3StaId": 16840,"cls1StaName": "美妆护肤","cls2StaName": "男士护肤","cls3StaName": "男士洁面","phPictureUrl": "https:///default_file/00/01/52/02.jpg","activityId": null,"activityTitle": null,"selfActivityId": null,"selfActivityTitle": null,"selfActivityType": null,"randomDeductionActivityId": null,"randomDeductionActivityTitle": null,"salePrice": 28.0,"realPrice": 28,"pointsPrice": 0,"rewardsPrice": 0,"empRewardsPrice": 0,"enterprisePrice": 0,"eleType": null,"eleDetailJson": null,"thirdServeId": null,"lineNo": "1","packageItem": [],"barcode": null,"exchangeJumpAddress": null,"skuSaleScale": null,"perWeight": null,"externalNumber": null,"externalPrice": null,"deliverType": 2,"serveHour": null,"serveFlag": 0,"qyMerchant": null,"qyAlias": null,"distributionHigherReferrerId": null,"thirdpartyDeliveryTime": null,"thirdpartyCompleteTime": null
}]

然后我们只需要取JSON的 skuName的内容就要用到这个函数

JSON_EXTRACT(t.json, '$.skuName') as sku_name

执行完存储过程，最后我们查询一下这个表ord_shopping