SELECT 
 value，
 SUM （年）AS年，
 SUM（总计）AS总额
从客户
 GROUP BY值; 
 

你想要年的总和和总和的总和， 按分组价值。

I'm trying to sum the values of rows two of which have duplicate values, the table I have is below:

Table name (Customers)

value   years   total
1           30    30
3           10    10
4           15    15
4           25    25

I would ideally like to finally have:

value  years   total
1      30      30
3      10      10
4      40      40

I've tried using SELECT DISTINCT and GROUP BY to get rid of the duplicate row, also the join in the code below isn't necessary. Regardless both commands come to no avail. Here's my code too:

SELECT DISTINCT 
  value,
  years,
  SUM(customer.years) AS total 
FROM customer 
INNER JOIN language 
  ON customer.expert=language.l_id 
GROUP BY 
  expert, 
  years;

But that produces a copy of the first table, any input welcome. Thanks!!!

SELECT
   value,
   SUM(years) AS years,
   SUM(total) AS total
FROM customers
GROUP BY value;

You want the sum of the years and the sum of the total, per — grouped by — value.