Question

Normally I make something like this.

#1 first query
 while () :
    #2 2nd queries
    #3 3rd queries
 endwhile;

to get a result. Now I want to combine them in one query. How can be done with this.

Table#1
-------------------------------------------
SELECT 
UserID, UserName, CountryCode, StateCode, CityCode, VillageCode, UserRace, UserStatus, UpdateStatus 
FROM user_locality
WHERE CountryCode = '{$getCountryCode}'

Table#2
-------------------------------------------
SELECT 
* 
FROM user_addresses 
WHERE address_UserID = '{$UserID}'

Table#3
-------------------------------------------
SELECT 
phone_UserID, phone_m, phone_h, phone_o 
FROM user_phones 
WHERE phone_UserID  = '{$UserID}'

Thank you.

Answer 1

You’ll want to use the JOIN clause. There are different types of joins. I’m using LEFT JOIN below which will select all records from user_locality and try to match records from both user_addresses and user_phones.

SELECT    *
FROM      `user_locality`
LEFT JOIN `user_addresses`
ON        `user_addresses`.`address_UserID` = `user_locality`.`UserID`
LEFT JOIN `user_phones`
ON        `user_phones`.`phone_UserID` = `user_locality`.`UserID`
WHERE     `user_locality`.`CountryCode` = '{$getCountryCode}'

The one thing to point out this query will result in more than 1 row for each user that has more than 1 phone or address.