select c.* from tr_card_info_gather_temp c where c.slot= 'ccc2/3' and c.dev_id = '219.141.128.30' UNION select t. from tr_card_info_gather_ext_temp t where t.slot= 'ccc2/3' and t.dev_id = '219.141.128.30' 找出bug

根据您提供的 SQL 语句，我发现第二个 SELECT 语句中的 t. 是有问题的，应该将其修改为正确的查询字段。正确的 SQL 语句应该为：

SELECT c.* FROM tr_card_info_gather_temp c WHERE c.slot = 'ccc2/3' AND c.dev_id = '219.141.128.30'
UNION
SELECT t.* FROM tr_card_info_gather_ext_temp t WHERE t.slot = 'ccc2/3' AND t.dev_id = '219.141.128.30'

这样就能正确地查询两张表中符合条件的数据，并将它们合并成一张结果表返回。

相关问题

SELECT c.dev_id,c.card_serial card_serial, t.card_serial sub_card_serial,t.sub_slot sub_slot FROM tr_card_info_gather_temp c left join tr_card_info_gather_ext_temp t on c.dev_id = t.dev_id and c.slot = t.slot 判断sub_slot不为空时取sub_card_serial，否则取card_serial

根据您给出的 SQL 语句，这是一个查询语句，目的是获取设备卡信息。根据您的要求，当 `sub_slot` 不为空时，需要取出 `sub_card_serial`，否则需要取出 `card_serial`。因此，可以使用 `CASE WHEN` 语句来实现这个逻辑，具体的 SQL 语句如下：

SELECT
    c.dev_id,
    CASE WHEN t.sub_slot IS NOT NULL THEN t.card_serial ELSE c.card_serial END AS card_serial,
    t.card_serial AS sub_card_serial,
    t.sub_slot AS sub_slot
FROM tr_card_info_gather_temp c
LEFT JOIN tr_card_info_gather_ext_temp t
ON c.dev_id = t.dev_id AND c.slot = t.slot;

这个查询语句使用了 `LEFT JOIN` 来连接两个表，使用 `CASE WHEN` 语句来根据 `sub_slot` 是否为空来判断是取 `card_serial` 还是 `sub_card_serial`。

select c.area_name,c.mon,c.count,ifnull(c1.count1,0),ifnull(c1.count1,0)/count * 100 from ( select a.area_name,MONTH(pb.wlpb_create_time) mon,count(pb.id) count from bc_company_info b inner join ( select b.id from wk_ledger_produce_gather g left join bc_company_info b on b.id =g.bci_id where g.wlpg_year =2022 group by b.id HAVING sum(g.wlpg_total_produce) >=30 UNION select b.id from wk_plan_info p left join wk_plan_danger d on d.wpi_id = p.id left join bc_company_info b on b.id = p.bci_id where p.wpi_year = 2022 group by b.id HAVING sum(d.wpd_this_produce) >30) b1 on b1.id = b.id left join wk_ledger_produce_bill pb on pb.bci_id = b.id left join sys_area a on a.id = b.bci_city where pb.wlpb_create_time >'2023-01-01 00:00:00' group by b.bci_city,MONTH(pb.wlpb_create_time) ) c left join ( select a.area_name,MONTH(pb.wlpb_create_time) mon,count(pb.id) count1 from bc_company_info b inner join ( select b.id from wk_ledger_produce_gather g left join bc_company_info b on b.id = g.bci_id where g.wlpg_year =2022 group by b.id HAVING sum(g.wlpg_total_produce) >=30 UNION select b.id from wk_plan_info p left join wk_plan_danger d on d.wpi_id = p.id left join bc_company_info b on b.id = p.bci_id where p.wpi_year = 2022 group by b.id HAVING sum(d.wpd_this_produce) >30) b1 on b1.id = b.id left join wk_ledger_produce_bill pb on pb.bci_id = b.id left join sys_area a on a.id = b.bci_city where pb.wldb_end_from != 1 and pb.wlpb_create_time >'2023-01-01 00:00:00' group by b.bci_city,MONTH(pb.wlpb_create_time)) c1 on c.area_name = c1.area_name and c.mon = c1.mon 这段SQL怎么优化

这段SQL语句比较复杂，可以考虑以下几个方面进行优化：

1. 索引优化：根据EXPLAIN命令的查询计划，确定哪些表需要添加索引，可以在表的关键字段上添加索引，提高查询效率。

2. 减少子查询：可以将子查询中的重复代码提取出来，避免多次重复查询。另外，可以考虑使用临时表或者表变量等方式，将子查询的结果存储在临时表中，然后再进行关联查询，避免多次重复查询。

3. 减少ifnull函数的使用：可以使用LEFT JOIN或者COALESCE函数代替ifnull函数，避免多次重复计算。

4. 确认需要查询的字段：可以根据实际需要，确认需要查询的字段，并且避免查询不必要的字段，提高查询效率。

总之，优化复杂SQL语句需要综合考虑多个方面，并且需要根据具体情况进行调整，从而提高查询效率。