MySQL之查詢多個相同表結構的數據

項目中數據量比較大需要每個月分一次表，按照時間分表；

分表查詢邏輯：先按條件查詢出要查詢的表，再去多張表里面查詢符合條件的數據

MySQL查表語句：

// 這種方式不支持條件查詢
show tables;

// 這種方式可以根據table_name字段匹配符合條件的表
select * from information_schema.tables where table_name like 'th%';

 

分出來的表一定是表結構相同的數據表，多張相同數據結構的表查詢語句：

// union all 關鍵字查詢
select * from thermal_oil_pipeline_202009060553 p
union all
select * from thermal_oil_pipeline_202009060553 p
union all
select * from thermal_oil_pipeline_202009060553 p

 

分頁查詢會用到符合條件數據總數量這個數據，分表查詢符合條件數據總量sql如下：

select sum(count) from (
	select count(p.id) as count from thermal_oil_pipeline as p 
	where  equipmentNo='FIC4' and createTime >= '2020-09-02 14:30:44' and createTime <= '2020-09-06 14:30:44'
	union all select count(p.id) as count from thermal_oil_pipeline_202009060553 as p 
	where  equipmentNo='FIC4' and createTime >= '2020-09-02 14:30:44' and createTime <= '2020-09-06 14:30:44'
) as total;