SQL查询NOT IN从3个条件表

Question

I have tables scructure:

old_data

| email | type |

///////////////////////////////

clients

| email1 |

//////////////////////////////

trashes

| email |

---

I need to find records that are not in table clients , but still exists in table old_data where it have type = 'Accounts'. So I wrote this code:

SELECT `email` FROM `old_data`
WHERE `type` = 'Accounts' AND `email` NOT IN (SELECT `email1` FROM `clients`))

Then I need to find in this result records, that are not in table trashes . So I wrote this code:

SELECT * FROM (SELECT `email` FROM `old_data` 
WHERE `type` = 'Accounts' AND `email` NOT IN (SELECT `email1` FROM `clients`)) AS t1 
WHERE t1.email NOT IN (SELECT `email` FROM `trashes`)

The problem here is, I have multiple records in table old_data for 1 email and type 'Accounts'. Same is in table trashes , but not in table clients . I need to write query like:

Get all records from old_data where is not clients email, but if clients email1 matches old_data email, remove all records with that emails from result. But then if from this result matches email with email from table trashes , remove from result only one record with that email.

Please help, I'm lost...

Answer 1

You can use not in by chaining the conditions.

SELECT od.`email`
FROM `old_data` od
WHERE od.`type` = 'Accounts' AND
      od.`email` NOT IN (SELECT `email1` FROM `clients`) AND
      od.email NOT IN (SELECT `email` FROM `trashes`);

I prefer not exists with a subquery because it handles NULL values better.

Answer 2

I managed to work it with another parameter.

SELECT * FROM (SELECT `email`, `secretId` FROM `old_data`
WHERE `type` = 'Accounts' AND `email` NOT IN (SELECT `email1` FROM `clients`)) AS t1 
WHERE t1.secretId NOT IN (SELECT `secretId` FROM `trashes` WHERE `type` = 'Accounts')

Also works with

SELECT od.`email`, od.`secretId`
FROM `old_data` od
WHERE od.`type` = 'Accounts' AND
      od.`email` NOT IN (SELECT `email1` FROM `clients`) AND
      od.`secretId` NOT IN (SELECT `secretId` FROM `trashes` WHERE `type` = 'Accounts');

---

Thanks for helping. :)