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# How to calculate the number of strings by means of grouping

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Good day, please tell me at what a question:

There is a table of type:

``````+ ----------------------- +.
| ID | User_ID | Point | Status |
-------------------------
| 1 | 1 | 3 | 0 |
-------------------------
| 2 | 1 | 3 | 0 |
-------------------------
| 3 | 2 | 1 | 0 |
-------------------------
| 4 | 2 | 0 | 0 |
-------------------------
| 5 | 3 | 3 | 0 |
-------------------------
| 6 | 3 | 1 | 0 |
-------------------------
| 7 | 1 | 0 | 1 |
+ ----------------------- +.
``````

What should be SQL request to get a table of type:

``````+ ----------------------- ------------ +.
| User_ID | Total_Point | Point_3 | Point_1 |
-------------------------------------
| 1 | 6 | 2 | 0 |
-------------------------------------
| 3 | 4 | 1 | 1 |
-------------------------------------
| 2 | 1 | 0 | 1 |
+ ----------------------------------- +
``````

To select the strings where Status = 0 and the sample was grouped by User_ID, also for each user_id, counted:

1. Total Points (Total_Point)
2. Number of points = 3 (Point_3)
3. Points = 1 (point_1)

and are ordered first by point_1, then Point_3 and Total_point.

You are confusedly confused in the query, Group BY is written once and after where it is written by Having and just alone on request. And having you will not help anything because it allows you to remove some collected groups from issuing. I think you would have to ask a question on the similarity “How to Calculate the amount by condition”, the rest then you have more than imagine.

``````select user_id, sum (point) as total_point, sum (point = 3) Point_3, SUM (Point = 1) Point_1
From table
WHERE STATUS = 0
Group by user_id
Order by Point_1, Point_3, Total_point
``````

The syntax is exclusively for MySQL, in other DBMS it would have to use `SUn (Case Point When 3 Then 1 ELSE 0 END) `. In MySQL, the comparison operator `point = 3 `returns 1 if the condition is executed and 0 if not. Sum simply summarizes the received units.

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