SQL

1. How to get the difference between two numbers from different rows in SQL (the max range in the column)

    ID	Amount
    101	10000
    101	5000
    101	3000

The result should be

ID	Amount
101	7000

Tip: Difference using Max & Min

2. How to get the date difference of last two max dates

Date
20-8-2019
25-8-2019
10-8-2019
29-8-2019

The result should be : 4 days -Difference between 29-8-2019 & 25-8-2019, which are the last two max days

Diff
4

Tip: Select max 2 and then difference using Max & Min

3. How do I keep adding data to a variable from a table

Name
Sandesh
Ramesh
Suresh

The result should be

Name
Sandesh, Ramesh, Suresh

Tip: COALESCE

4 Output ?

- Select 1a
- Select a =15
- select number from (values (1, 3), (2, 4)) as X(number, dummy)
- SELECT * FROM (values (1),(2),(null)) as c(id) where c.Id in (1,3, null)
- SELECT * FROM (values (1),(2),(null)) as c(id) where c.Id not in (1,3, null)

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• SQL Puzzles