合并/加入sql查询

bttbmeg0  于 2021-08-01  发布在  Java
关注(0)|答案(1)|浏览(327)

我有一个查询,它从json文档中获取数据,检查返回了哪些值,然后返回该计数。

  1. SELECT
  2. (CASE WHEN cat_name IS NOT NULL THEN 1 ELSE 0 END +
  3. CASE WHEN dog_name IS NOT NULL THEN 1 ELSE 0 END
  4. ) AS cat_dog_total
  5. from (select JSON_EXTRACT_SCALAR(data, '$.cat.name') as cat_name
  6. JSON_EXTRACT_SCALAR(data, '$.dog.name') as dog_name
  7. from table
  8. )

作为查询的一部分,我还想返回 cat_name , dog_name 并添加一个 WHERE pet_store = 'london' 我不确定应该在哪里添加其他参数,或者是否应该加入子查询?

j8ag8udp

j8ag8udp1#

  1. SELECT cat_name, dog_name,
  2. (CASE WHEN cat_name IS NOT NULL THEN 1 ELSE 0 END +
  3. CASE WHEN dog_name IS NOT NULL THEN 1 ELSE 0 END
  4. ) AS cat_dog_total
  5. from (select JSON_EXTRACT_SCALAR(data, '$.cat.name') as cat_name
  6. JSON_EXTRACT_SCALAR(data, '$.dog.name') as dog_name
  7. from table
  8. WHERE pet_store = 'london'
  9. )

相关问题