CODEWITHSUNDEEP
sqlpivot
user1882705
user1882705

Reputation: 1081

How to merge two rows into one row in sql?

I have a table as

EmployeeID    IndividualPay  FamilyPay   IsActive
    1            200          300        true
    1            100          150        false

But I want the output as follows(I want to use this output to inner join with some other table)

EmployeeID  IndPay_IsActive  IndPay_IsNotActive FamilyPay_IsActive   FamilyPay_IsNotActive 
    1            200                 100              300                   150

I have looked into PIVOT, but not sure how to use it in my case.

Upvotes: 16

Views: 79263

Answers (2)

Taryn
Taryn

Reputation: 247670

This type of transformation is known as a pivot. You did not specify what database you are using but you can use an aggregate function with a CASE expression in any system:

select employeeid,
  max(case when IsActive = 'true' then IndividualPay end) IndPay_IsActive,
  max(case when IsActive = 'false' then IndividualPay end) IndPay_IsNotActive,
  max(case when IsActive = 'true' then FamilyPay end) FamilyPay_IsActive,
  max(case when IsActive = 'false' then FamilyPay end) FamilyPay_IsNotActive
from yourtable
group by employeeid

See SQL Fiddle with Demo

Depending on your database, if you have access to both the PIVOT and UNPIVOT functions, then they can be used to get the result. The UNPIVOT function converts the IndividualPay and FamilyPay columns into rows. Once that is done, then you can create the four new columns with the PIVOT function:

select *
from
(
  select employeeid,
    case when isactive = 'true'
      then col+'_IsActive'
      else col+'_IsNotActive' end col, 
    value
  from yourtable
  unpivot
  (
    value
    for col in (IndividualPay, FamilyPay)
  ) unpiv
) src
pivot
(
  max(value)
  for col in (IndividualPay_IsActive, IndividualPay_IsNotActive,
              FamilyPay_IsActive, FamilyPay_IsNotActive)
) piv

See SQL Fiddle with Demo.

Both give the same result:

| EMPLOYEEID | INDIVIDUALPAY_ISACTIVE | INDIVIDUALPAY_ISNOTACTIVE | FAMILYPAY_ISACTIVE | FAMILYPAY_ISNOTACTIVE |
----------------------------------------------------------------------------------------------------------------
|          1 |                    200 |                       100 |                300 |                   150 |

Upvotes: 34

Ray Saltrelli
Ray Saltrelli

Reputation: 4218

Select
    EmployeeID,
    Active.IndividualPay As IndPay_IsActive,
    Active.FamilyPay As FamilyPay_IsActive,
    Inactive.IndividualPay As IndPay_IsNotActive,
    Inactive.FamilyPay As FamilyPay_IsNotActive
From
    PayTable Active
    Join PayTable Inactive On Active.EmployeeID = Inactive.EmployeeId
        And Inactive.IsActive = 'false'
Where
    Active.IsActive = 'true'

Upvotes: 4

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