join 2 mysql select based on text field - mysql

Question

I have the 2 following select in Mysql:
1st select:
(SELECT DISTINCT `Online_playerdatabase_v2`.`Player`,
Online_playerdatabase_v2.First_Deposit_Date As FirstDep,
TRUNCATE(Online_playerdatabase_v2.Balance,2) as Balance
FROM Online_playerdatabase_v2
WHERE `Online_playerdatabase_v2`.`Player`<>'Player'
ORDER BY `Online_playerdatabase_v2`.`Balance` DESC;
2d select:
SELECT DISTINCT(Online_customer_activity_v2.Customers) as Player,
max(Online_customer_activity_v2.Date) as LastAction
FROM Online_customer_activity_v2
WHERE `Online_customer_activity_v2`.`Total_Bets`>0
Group by Online_customer_activity_v2.Customers
Output Select 1
Player FirstDep Balance
Ray 2014-10-19 9100.00
Ramzi 2014-11-02 9.61
tareq 2014-11-06 805.00
STAN 2014-10-17 7.50
Bill 2014-03-25 68.40
karam 2014-11-16 676.50
Abdul 2014-11-13 650.00
Renaud 2014-03-12 507.00
John 2014-11-22 500.00
Output select 2
Player LastAction
John 2015-11-13
Bill 2014-12-14
Renaud 2015-03-14
Abdul 2015-11-16
Ray 2015-11-22
STAN 2015-10-29
Ramzi 2015-11-10
Tarek 2015-05-10
karam 2014-12-10
Abdul 2015-02-10
Desired Output, a join on both Select that adds following calculations:
active days (FirstDep-LastAction) and Days_last_Visit (CurrentDate - Last Action)
Summarized in following table:
Player FirstDep Balance LastAction Active_days Days_last_Visit
Ray 2014-10-19 9100.00 2015-11-22 399 1
Ramzi 2014-11-02 9.61 2015-11-10 373 13
tareq 2014-11-06 805.00 2015-05-10 185 197
STAN 2014-10-17 7.50 2015-10-29 377 25
Bill 2014-03-25 68.40 2014-12-14 264 344
karam 2014-11-16 676.50 2014-12-10 24 348
Abdul 2014-11-13 650.00 2015-02-10 89 286
Renaud 2014-03-12 507.00 2015-03-14 367 254
John 2014-11-22 500.00 2015-11-13 356 10
Your help is greatly appreciated!
Thanks

Answer 1

The following query should give the result you want. I will add that I joined the two tables from your intermediate queries above using the Player field. This is not a very robust way to join, because the name may not be unique among all players in the table. A better way to join would be to use a unique identifier of some sort.
SELECT t1.Player, t1.FirstDep, t1.Balance, t2.LastAction,
DATEDIFF(t2.LastAction, t1.FirstDep) AS Active_days,
DATEDIFF(NOW(), t2.LastAction) AS Days_last_Visit
FROM
(
SELECT DISTINCT `Online_playerdatabase_v2`.`Player`,
Online_playerdatabase_v2.First_Deposit_Date AS FirstDep,
TRUNCATE(Online_playerdatabase_v2.Balance,2) AS Balance
FROM Online_playerdatabase_v2
WHERE `Online_playerdatabase_v2`.`Player` <> 'Player'
) t1
INNER JOIN
(
SELECT DISTINCT(Online_customer_activity_v2.Customers) AS Player,
MAX(Online_customer_activity_v2.Date) AS LastAction
FROM Online_customer_activity_v2
WHERE `Online_customer_activity_v2`.`Total_Bets` > 0
GROUP BY Online_customer_activity_v2.Customers
) t2
ON t1.`Player` = t2.`Player`

Answer 2

You need to join the 2 selects as subqueries in a 3rd select using the player field. The Active_days and Days_last_Visit fields can be calculated using the DateDiff() function.
SELECT *
,DateDiff(t2.LastAction,t1.FirstDep) AS Active_days
,DateDiff(CURDATE(), t2.LastAction) AS Days_last_Visit
FROM
(SELECT DISTINCT `Online_playerdatabase_v2`.`Player`,
Online_playerdatabase_v2.First_Deposit_Date As FirstDep,
TRUNCATE(Online_playerdatabase_v2.Balance,2) as Balance
FROM Online_playerdatabase_v2
WHERE `Online_playerdatabase_v2`.`Player`<>'Player'
ORDER BY `Online_playerdatabase_v2`.`Balance` DESC) t1
LEFT JOIN
(SELECT DISTINCT(Online_customer_activity_v2.Customers) as Player,
max(Online_customer_activity_v2.Date) as LastAction
FROM Online_customer_activity_v2
WHERE `Online_customer_activity_v2`.`Total_Bets`>0
Group by Online_customer_activity_v2.Customers) t2
ON t1.Player=t2.Player
You have to consider, however, how you join the 2 datasets. I used left join, since the players table will probably hold all players, but you may want to go for inner join or simulate a full outer join depending your requirements and your data.