Stefan Motz
asked on
SQL Server Query
Hi Experts,
I have a table where the the columns are named Day1, Day2, Day3, etc.
I have 35 datetime data type columns like this.
When I search the Day1 column for February dates I do it like this:
Select * from VacationBid WHERE DATEPART(mm,Day1) = 2 and DATEPART(yyyy,Day1)<>1900
My goal is to display all records where to month is February in any of the 35 columns not only in the Day1 column.
Is it possible to retrieve all February records from all the 35 columns with one single query, instead of doing it one by one, like it is done below?
Select * from VacationBid WHERE DATEPART(mm,Day1) = 2 and DATEPART(yyyy,Day1)<>1900
Select * from VacationBid WHERE DATEPART(mm,Day2) = 2 and DATEPART(yyyy,Day2)<>1900
Select * from VacationBid WHERE DATEPART(mm,Day3) = 2 and DATEPART(yyyy,Day3)<>1900
Thank you for your help?
I have a table where the the columns are named Day1, Day2, Day3, etc.
I have 35 datetime data type columns like this.
When I search the Day1 column for February dates I do it like this:
Select * from VacationBid WHERE DATEPART(mm,Day1) = 2 and DATEPART(yyyy,Day1)<>1900
My goal is to display all records where to month is February in any of the 35 columns not only in the Day1 column.
Is it possible to retrieve all February records from all the 35 columns with one single query, instead of doing it one by one, like it is done below?
Select * from VacationBid WHERE DATEPART(mm,Day1) = 2 and DATEPART(yyyy,Day1)<>1900
Select * from VacationBid WHERE DATEPART(mm,Day2) = 2 and DATEPART(yyyy,Day2)<>1900
Select * from VacationBid WHERE DATEPART(mm,Day3) = 2 and DATEPART(yyyy,Day3)<>1900
Thank you for your help?
ASKER
This is interesting but I'm not able to customize it to my needs.
Would I have to start with something like this?
DECLARE @t TABLE (Day1 datetime, Day2 datetime, Day3 datetime, Day4 datetime, Day5 datetime)
INSERT INTO @t (Day1, Day2, Day3, Day4, Day5)
SELECT Day1 WHERE DATEPART(mm,Day1) = 2 from VacationBid UNION ALL
SELECT Day2 WHERE DATEPART(mm,Day2) = 2 from VacationBid UNION ALL
Would I have to start with something like this?
DECLARE @t TABLE (Day1 datetime, Day2 datetime, Day3 datetime, Day4 datetime, Day5 datetime)
INSERT INTO @t (Day1, Day2, Day3, Day4, Day5)
SELECT Day1 WHERE DATEPART(mm,Day1) = 2 from VacationBid UNION ALL
SELECT Day2 WHERE DATEPART(mm,Day2) = 2 from VacationBid UNION ALL
The MS converts the table you have into a dynamic table of the layout you want
Declare @t table (columns preceeding the ,days as varchar , date as datetime)
What columns preceed the datetime columns?
I.e. You have 1,day1,day2,day3
End up
ID,days,date
1,day1,date
1,day2,date
1,day3,date
This will be the table you would query the date for the range you want.
Declare @t table (columns preceeding the ,days as varchar , date as datetime)
What columns preceed the datetime columns?
I.e. You have 1,day1,day2,day3
End up
ID,days,date
1,day1,date
1,day2,date
1,day3,date
This will be the table you would query the date for the range you want.
ASKER
I have columns named ID, First_Name, Last_Name, Emp_Id, Day1, Day2, Day3... up to Day35
I just don't know how to declare them to insert them into the dynamic table.
ID is int
First_Name is varchar(25)
Last_Name is varchar(25)
The day columns are datetime
I just don't know how to declare them to insert them into the dynamic table.
ID is int
First_Name is varchar(25)
Last_Name is varchar(25)
The day columns are datetime
ASKER CERTIFIED SOLUTION
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Had to correct, day is a reserved word, so when using it as a column, it has to be in quotes (")
ASKER
This is perfect, thank you very much for walking me through. I've learned something very useful.
An example of an unpivot is displayed at an MS
Such that you have the
Entries,datetime as a single column per row.
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/bee65313-cfd0-43bb-bbf6-30ff9ddc0c9a/sql-query-rows-to-columns?forum=transactsql
Pivot rows to column
Unpivot columns to rows.
https://technet.microsoft.com/en-us/library/ms177410(v=sql.90).aspx
The example on social ms is to be used an example to first convert the table data (unpivot) having the day1-day35 shifted out such that there will be one datetime per row
Then you would use the resulting table to run your query searching for the dates of interest in the single datetime column.