Select query except another table - mysql

Question

I got 2 tables.
TABLE 1
ID FRANCHISENAME TELEPHONE FRANCHISE_ID
1 BURGER 666-555-999 5
2 JSUBS 666-555-999 7
3 STEAKS 777-888-999 3
TABLE 2
ID NAME TELEPHONE EMAIL FRANCHISE_ ID
5 JOHN 555-444-333 JOHN#GMAIL.COM 5
5 JOHN 555-444-333 JOHN#GMAIL.COM 7
6 EDGARD 555-444-333 EDGARD#GMAIL.COM 9
I want to retrieve all data in table one, except for that data where the user has his email in Table 2. As for example JOHN has franchise_id 5 and 7, so the query would only return
3 STEAKS, 777-888-999, 3

Answer 1

Assuming that TABLE_1 & TABLE_2 relate to each other through TABLE_1.FRANCHISE_ID & TABLE_2.FRANCHISE_ID
You can use NOT EXISTS
SELECT
*
FROM TABLE_1 T1
WHERE NOT EXISTS(
SELECT *
FROM TABLE_2 T2
WHERE T2.FRANCHISE_ID = T1.FRANCHISE_ID
AND T2.EMAIL = 'JOHN#GMAIL.COM'
)
OR
You can use LEFT JOIN along with IS NULL
SELECT
T1.*
FROM TABLE_1 T1
LEFT JOIN TABLE_2 T2 ON T1.FRANCHISE_ID = T2.FRANCHISE_ID
WHERE T2.FRANCHISE_ID IS NULL;

Answer 2

SELECT t1.*
FROM
Table1 t1
LEFT JOIN Table2 t2
ON t1.FRANCHISE_ID = t2.FRANCHISE_ID
AND LEN(IFNULL(t2.EMAIL,'')) > 0
WHERE
t2.ID IS NULL
Even if there is a record in Table 2 if it has no email it will be returned by this query. You can expand say to > 7 or more to check for a minimum level of validity of email address.

Answer 3

This should get you there using the NOT IN function. It will exclude records from Table 1 if there is a matching Franchise ID in Table 2, unless the email field is Table 2 is null:
SELECT * FROM Table1
WHERE Table1.Franchise_ID NOT IN
(SELECT Table2.Franchise_ID FROM Table2
WHERE Table2.Email IS NOT NULL);