SQL Server Query – Return Column Name and Date

sql serversql-server-2012t-sql

I have a SQL Table that houses the date that a student was assigned and completes one of three exams. I am in need of a way to query the table and return the column name of the exam the student needs to take and the date it was assigned.

For example, these are my desired query results:

Joe - exam1date - 01-30-2018
James - exam2date - 03-02-2018
Javier - exam3date - 04-01-2018

And this is DDL for my table:

Create Table Information 
(
   fname varchar(100)
  ,exam1date date
  ,exam1complete date
  ,exam2date date
  ,exam2complete date
  ,exam3date date
  ,exam3complete date
)

Insert Into Information (fname, exam1date)
Values ('joe', '2018-01-30')
INSERT INTO Information (fname, exam1date, exam1complete, exam2date)
Values ('james', '2018-02-14', '2018-02-21', '2018-03-02')
INSERT INTO Information (fname, exam1date, exam1complete, exam2date, exam2complete, exam3date)
VALUES ('javier', '2018-01-01', '2018-01-14', '2018-03-01', '2018-03-12', '2018-04-01')

What would a query be that can returned my desired result set from the above table schema?

Best Answer

I guessing that you need the examdate of the last exam that does not have a complete date?

Query

 SELECT fname,  
        CASE 
        WHEN exam1complete IS NULL THEN 'exam1date'
        WHEN exam2complete IS NULL THEN 'exam2date '
        ELSE 'exam3date' END AS columnname,
        CASE
        WHEN exam1complete IS NULL then exam1date 
        WHEN exam2complete IS NULL then exam2date 
        ELSE exam3date END AS examdate
FROM Information;

Result

fname   columnname  examdate
joe exam1date   2018-01-30
james   exam2date   2018-03-02
javier  exam3date   2018-04-01

Related Solutions

SQL Server – Using Column Names in Separate Table

What you're looking for is Dynamic SQL Pivots. A PIVOT will turn row values into columns based on an aggregate, however you need to define the column names as part of the PIVOT, luckily we can do that on the fly with dynamic SQL. The following should generate the result set you want for a particular company (replace rowValues with your table name):

DECLARE @SQL NVARCHAR(MAX)
DECLARE @Columns NVARCHAR(MAX)
DECLARE @Company NVARCHAR(5) = '01'

SET @Columns = STUFF( (SELECT ',['+H.description+']' AS [data()] 
                        FROM dbo.Headers H
                        WHERE H.company = @Company  
                        ORDER BY H.fieldNumber
                        FOR XML PATH('')),1,1,'')

SET @SQL = '
SELECT company,jobNumber,'+@Columns+'
FROM
(
    SELECT h.company,RV.jobNumber,RV.information,h.description
    FROM Headers h
            INNER JOIN dbo.RowValues RV
                ON RV.fieldNumber = h.fieldNumber
                   AND RV.company = h.company
    WHERE h.company = '+@Company+'  
) as Data
PIVOT
(
    MAX(information) FOR [description] IN ('+@Columns+')
) as p
ORDER BY jobNumber ASC'

EXEC sp_executesql @sql;

Unfortunately due to the possibility that different companies will have different columns there is no reliable way to combine all the the possible sets the above query could generate. Depending on how you want to use this query the easy option is to loop through all the companies and call an SP that contains the above, allowing you to output each company as a separate SELECT. Or you can do something with your SSIS package to output each one into a file.

If you want to insert the data into a table matching the calculated schema you can do a SELECT INSERT and a bit more dynamic SQL to get the data where it needs to go.

SQL Server – How to Check for Non-Ascii Characters

Ranges in the pattern syntax use the sorting rules of your collation.

Use a binary collate clause so the range is ordered by character code.

(I also changed it to LIKE as I find that more obvious than PATINDEX > 0)

SELECT *      
FROM mbrnotes      
WHERE LINE_TEXT LIKE '%[' + CHAR(127)+ '-' +CHAR(255)+']%'  COLLATE Latin1_General_100_BIN2

Related Question