Select/Join multiple row values from Column A if dates in Column B are within 'x' seconds of each other

I have the following Database structure and need a query to work in SQL Server 2008 and also SQL Server 2014.

Database: ASSETS

Table: COMPUTERS

PK (GUID)      (nvarchar)   (nvarchar)
|    PC_ID    |  PC_Hostname  |  Win_Ver |
+-------------+---------------+----------+
| ABCDE-12345 |   ACMEINC_1   |   W732   |
| FGHIJ-67890 |   ACMEINC_2   |   W732   |
| QWERT-34567 |   ACMEINC_3   |   W764   |
| JHGFD-87654 |   ACMEINC_1   |   W764   |
| CVBNM-08643 |   ACMEINC_1   |   W1064  |

Table: SOFTWARE

PK (GUID)      (GUID)      (int)   (nvarchar)         (datetime)
|    REG_ID   |    PC_ID    | SWType |  NAME_Reg |         DATE_Reg        |
+-------------+-------------+--------+-----------+-------------------------+
|  2WS3-8574  | ABCDE-12345 |    8   |   Bob     | 2018-02-19 15:30:10.980 |
|  D46G-2574  | ABCDE-12345 |    7   |   Admin   | 2018-02-19 15:30:12.001 |
|  7F4H-6523  | FGHIJ-67890 |    7   |   NULL    | 2018-03-01 11:02:02.954 |
|  MNDE-4567  | QWERT-34567 |    8   |   Joan    | 2018-11-23 09:28:59.685 |
|  8S22-1254  | QWERT-34567 |    7   | Warehouse | 2018-11-23 09:29:00.103 |
|  C9CC-1854  | JHGFD-87654 |    8   |   Barry   | 2018-11-23 09:46:21.321 |
|  JH21-6325  | JHGFD-87654 |    7   | Accounts  | 2018-11-23 09:46:21.332 |
|  109A-4785  | CVBNM-08643 |    8   |   Sally   | 2019-01-02 12:59:59.753 |
|  34NB-6855  | CVBNM-08643 |    7   |    HR     | 2019-01-02 13:00:00.211 |

I'm trying to query the SOFTWARE table for values in the 'NAME_Reg' column where not 'NULL'.

If two 'DATE_Reg' values are =< 5 sec apart they should be displayed in results on one row with the value matching 'SWType' of 8 in the 'Name' column, and the value matching 'SWType' of 7 in the 'Dept' column.

There will only ever by 2 entries in 'DATE_Reg' within a 5 sec time range of each other.

The results should display the corresponding 'PC_Hostname' linked on 'PC_ID', and the 'DATE_Reg' value corresponding to the 'SWType' value of 8 (Really I'd b

You can join the software table to itself and use DATEADD() for the 5 second condition:

SELECT
    c.PC_Hostname,
    a.NAME_Reg     AS Name,
    b.NAME_Reg     AS Dept,
    a.DATE_Reg,
    b.DATE_Reg     AS DATE_Reg_b 
FROM
    assets.software AS a
  JOIN
    assets.software AS b
  ON    a.PC_ID  = b.PC_ID
    AND a.SWType = 8
    AND b.SWType = 7
    AND a.DATE_Reg >= DATEADD(second, -5, b.DATE_Reg)
    AND a.DATE_Reg <= DATEADD(second, +5, b.DATE_Reg)
  LEFT JOIN
    assets.computers AS c
  ON   a.PC_ID = c.PC_ID
WHERE
      a.NAME_Reg IS NOT NULL
  AND b.NAME_Reg IS NOT NULL
  ;

StackExchange Database Administrators Q#230146, answer score: 2