Get data from multiple tables in MySQL - mysql

Question

Table 1 :- tbl_contacts
Fields
user_id
contact_id
first_name
last_name
Table 2 :- tbl_phone_details
Fields
contact_id
phone_number
phone_type
Table 3 :- tbl_email_details
Fields
contact_id
email_address
email_type
QUERY -
SELECT
tbl_contacts.*, tbl_email_details.*, tbl_phone_details.*
FROM
tbl_contacts, tbl_email_details,
tbl_phone_details
WHERE
tbl_contacts.user_id = '1'
I want to get first_name, last_name, Phone and Email details of particular user_id. I have used above query but its giving me repeated results and I am having less knowledge on DB queries like JOIN and INNER QUERY.
If anyone has any idea, please kindly help.
OUTPUT NEEDED:-
contact_id, first_name, last_name, phone_number, phone_type, email_address, email_type
(Here email and phone number can have 1 or more values for particular users).

Answer 1

Try like this
If you want to retrieve data for particular ID
SELECT T.contact_id,
T.first_name,
T.last_name,
P.phone_number,
P.phone_type,
E.email_address,
E.email_type
FROM tbl_contacts T LEFT JOIN tbl_phone_details P ON
T.contact_id = P.contact_id
LEFT JOIN tbl_email_details E ON
T.contact_id = E.contact_id
WHERE T.contact_id = #contact_id
If you want to retrieve all data
SELECT T.contact_id,
T.first_name,
T.last_name,
P.phone_number,
P.phone_type,
E.email_address,
E.email_type
FROM tbl_contacts T LEFT JOIN tbl_phone_details P ON
T.contact_id = P.contact_id
LEFT JOIN tbl_email_details E ON
T.contact_id = E.contact_id

Answer 2

SELECT tbl_contacts.*, tbl_email_details.*, tbl_phone_details.* FROM
tbl_contacts, tbl_email_details, tbl_phone_details WHERE
tbl_contacts.user_id = '1'
You forgot to mention the condition by which you are going to join all the tables!
SELECT c.first_name, c.last_name, p.phone_number, e.email_address
FROM tbl_contacts c, tbl_email_details e, tbl_phone_details p
WHERE tbl_contacts.user_id = '1'
AND c.contact_id = e.contact_id
AND e.contact_id = p.contact_id;

Answer 3

SELECT c.contact_id, c.first_name, c.last_name,
phone.phone_number, phone.phone_type,
email.email_address, email.email_type
FROM tbl_contacts c
LEFT JOIN tbl_email_details email ON c.contact_id = email.contact_id
LEFT JOIN tbl_phone_details phone ON c.contact_id = phone.contact_id
WHERE tbl_contacts.user_id = '1'

Answer 4

Sql queries are easy to learn and write and they are very useful in getting the important data from database. Joins are used to basically fetch the data from two or more tables on the bases of common column in both tables.
Inner Join will select those values that are common in both of the tables.
Left Join will select all the data from the left table and Right Join will select all the data from right table on the basis of id.
These are the basics of SQL and you must know how to fetch accurate data using them.

Answer 5

this is how I would make that request with JOIN ... but there might be some better or faster way to do it.
SELECT first_name, last_name, phone_number, email_address
FROM tbl_contacts
JOIN tbl_phone_details
ON tbl_contacts.contact_id=tbl_phone_details.contact_id
JOIN tbl_email_details
ON tbl_email_details.contact_id=tbl_contacts.contact_id
WHERE tbl_contacts.user_id = '1';
And just so you don't get lost in all the different answers here (which are probably all correct):
you don't need to give an aliase name to your tables (it's just for readability)
you don't need to mention the table names in your column list if the column name is unique (e.g first_name is only in tbl_contacts). Just if you want the contact_id then you should decide which one (e.g. tbl_phone_details.contact_id)
the multi-select as Jayaram proposed, is exactly the same as the JOIN. MySQL handles both queries the same way (I just didn't see his answer when I responded, sorry)