using JOINS to concatenate user's data from multiple tables MySQL

Question

I need to export the data from several tables into a .csv file. I've written the CSV output code but now I need to structure the query properly.

Each table contains a USER_ID field. This field is used to relate the user's data from one table to another. I need to grab all the data from these tables, with each user's information fully represented on a single row.

simple example of what I need:

TABLE A
|USER ID | NAME | FAVORITE_COLOR | AGE |
|007     |James | black          | 46  |
----------------------------------------

TABLE B
|USER ID | JOB | LOCATION | NOTES    |
|007     |Agent| N/A      | cool guy | 
--------------------------------------


JOINED OUTPUT I NEED (albeit with many more users / tables):
|USER ID | NAME | FAVORITE_COLOR | AGE | JOB | LOCATION | NOTES    |
|007     |James | black          | 46  |Agent| N/A      | cool guy |
--------------------------------------------------------------------

I know this can be accomplished with joins but I'm not sure how to make a query which selects ALL the users, and joins ALL their data from several tables, so that each user is a single row with all their data.

Any help or a code nudge in the right direction is appreciated! :)

Answer 1

试试这个查询

select t1.*,t2.* from table_1 as t1 left join table_2 as t2 on t1.user_id = t2.user_id 

Answer 2

try this

 select t1.USER ID , NAME , FAVORITE_COLOR , AGE ,JOB , LOCATION , NOTES 
 from TABLE1 t1 
 INNER JOIN table2 t2  
 ON t1.USER_ID = t2.USER_ID

EDIT>

if you have 3 or 4 tables then just join them you can add this

  INNER JOIN table3 t3  
  ON t2.USER_ID = t3.USER_ID
  INNER JOIN table4 t4  
  ON t3.USER_ID = t4.USER_ID

Answer 3

With the following tables

TABLE A
|USER ID | NAME | FAVORITE_COLOR | AGE |
|007     |James | black          | 46  |
|008     |John  | Doe            | 77  |
|010     |Amy   | McClain        | 26  |
----------------------------------------

TABLE B
|USER ID | JOB | LOCATION | NOTES    |
|007     |Agent| N/A      | cool guy |
|010     |Agent| MI       | babe     | 
--------------------------------------

SELECT TableA.*, TableB.*
FROM TableA
LEFT JOIN TableB
ON TableA.[USER ID] = TableB.[USER ID]

Will will pull all records found in TableA regardless of if there is a matching record in TableB . Here is what the results would look like:

|USER ID | NAME | FAVORITE_COLOR | AGE | JOB | LOCATION | NOTES    |
|007     |James | black          | 46  |Agent| N/A      | cool guy |
|008     |John  | Doe            | 77  |Null | Null     | Null     |
|010     |Amy   | McClain        | 26  |Agent| MI       | babe     |

By changing the LEFT JOIN to a INNER JOIN you can force the query to pull only records that are found in both tables. Here is what the results would look like:

|USER ID | NAME | FAVORITE_COLOR | AGE | JOB | LOCATION | NOTES    |
|007     |James | black          | 46  |Agent| N/A      | cool guy |
|010     |Amy   | McClain        | 26  |Agent| MI       | babe     |

Answer 4

试试这个查询

$qry = "SELECT t1.USER_ID,t1.NAME,t1.FAVORITE_COLOR,t1.AGE,t2.JOB,t2.LOCATION,t2.NOTES FROM TABLE_1 as t1 LEFT JOIN TABLE_2 as t2 ON t1.USER_ID = t2.USER_ID";