How to merge rows to one row in SQL Server - sql-server

Question

I have a table like this:
- ID | CurrencyID | LendID | Price
- 3 | 1 | 1 | 1.2
- 3 | 1 | 2 | 1.3
- 3 | 1 | 3 | 1.4
- 3 | 2 | 1 | 1.5
- 3 | 2 | 2 | 1.6
- 3 | 2 | 3 | 1.7
- 4 | 2 | 3 | 2.0
There are totally 4 currencies 1,2,3,4
There are totally 3 lend 1,2,3
I want to get a result like below:
ID | CurrencyIDLendID_11_Price | CIDID_12_Price | CIDLID_13_Price | CIDLID_21_Price | CIDLID_22_Price | CIDLID_23_Price | CIDLID_31_Price | CIDLID_32_Price | CIDLID_33_Price | CIDLID_41_Price | CIDLID_42_Price | CIDLID_43_Price
3 | 1.2 | 1.3 | 1.4 | 1.5 | 1.6 | 1.7 | 0 | 0 | 0 | 0 | 0 | 0
4 | 0 | 0 | 0 | 0 | 0 | 2.0 | 0 | 0 | 0 | 0 | 0 | 0
I know it is now good description, but what I want to do is to merge many records to one record.

Answer 1

This is called pivoting and one of the ways how to do the pivoting is to use grouping with conditional aggregating:
WITH cidlid AS (
SELECT
ID,
CurrencyIDLendID = CurrencyID * 10 + LendID,
Price
FROM atable
)
SELECT
ID,
CurrencyIDLendID_11_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 11 THEN Price END), 0),
CurrencyIDLendID_12_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 12 THEN Price END), 0),
CurrencyIDLendID_13_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 13 THEN Price END), 0),
CurrencyIDLendID_21_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 21 THEN Price END), 0),
CurrencyIDLendID_22_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 22 THEN Price END), 0),
CurrencyIDLendID_23_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 23 THEN Price END), 0),
CurrencyIDLendID_31_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 31 THEN Price END), 0),
CurrencyIDLendID_32_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 32 THEN Price END), 0),
CurrencyIDLendID_33_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 33 THEN Price END), 0),
CurrencyIDLendID_41_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 41 THEN Price END), 0),
CurrencyIDLendID_42_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 42 THEN Price END), 0),
CurrencyIDLendID_43_Price = COALESCE(SUM(CASE CurrencyIDLendID WHEN 43 THEN Price END), 0)
FROM cidlid
GROUP BY ID
If all the (CurrencyID, LendID) combinations are guaranteed to be unique within same ID groups, you can also use MIN or MAX instead of SUM.

Answer 2

You could use the PIVOT Syntax starting with SQL Server 2005
Declare #Data table (ID int, CurrencyID int, LendID int , price decimal (4,2))
INSERT INTO #Data
SELECT 3 as ID, 1 as CurrencyID, 1 as LendID , 1.2 as price
UNION SELECT 3 , 1 , 1 , 1.2
UNION SELECT 3 , 1 , 2 , 1.3
UNION SELECT 3 , 1 , 3 , 1.4
UNION SELECT 3 , 2 , 1 , 1.5
UNION SELECT 3 , 2 , 2 , 1.6
UNION SELECT 3 , 2 , 3 , 1.7
UNION SELECT 4 , 2 , 3 , 2.0
SELECT
ID,
COALESCE([1_1],0) as CurrencyIDLendID_11_Price ,
COALESCE([1_2],0) as CIDID_12_Price ,
COALESCE([1_3],0) as CIDLID_13_Price ,
COALESCE([2_1],0) as CIDLID_21_Price ,
COALESCE([2_2],0) as CIDLID_22_Price ,
COALESCE([2_3],0) as CIDLID_23_Price ,
COALESCE([3_1],0) as CIDLID_31_Price ,
COALESCE([3_2],0) as CIDLID_32_Price ,
COALESCE([3_3],0) as CIDLID_33_Price ,
COALESCE([4_1],0) as CIDLID_41_Price ,
COALESCE([4_2],0) as CIDLID_42_Price ,
COALESCE([4_3],0) as CIDLID_43_Price
FROM (
SELECT
ID,
cast(CurrencyID as varchar) + '_' + CAST(lendID as varchar) ColumnHeader,
price FROM #Data ) src
PIVOT (SUM(price) for ColumnHeader IN
([1_1], [1_2],[1_3],
[2_1], [2_2],[2_3],
[3_1], [3_2],[3_3],
[4_1], [4_2],[4_3])
) as pivottable
which outputs
ID CurrencyIDLendID_11_Price CIDID_12_Price CIDLID_13_Price CIDLID_21_Price CIDLID_22_Price CIDLID_23_Price CIDLID_31_Price CIDLID_32_Price CIDLID_33_Price CIDLID_41_Price CIDLID_42_Price CIDLID_43_Price
----------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- --------------------------------------- ---------------------------------------
3 1.20 1.30 1.40 1.50 1.60 1.70 0.00 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00 2.00 0.00 0.00 0.00 0.00 0.00 0.00
Note: I kept your column names