Converting SQL Server date to Oracle

Question

From SQL Server , I need to be able to pull some information from an Oracle database based on a date column.

SET @foo = 'SELECT * from OPENQUERY(' + @LinkedServer +
', ''SELECT *
    FROM Table1
    WHERE date_revised > '''''+@myDate+'''''')'

Don't mind if the numbers of ' is off... I cut things out to make this shorter. I have tried using convert() on the SQL Server side, but I cannot seem to find a format that Oracle accepts, so it keeps throwing errors.

At a minimum, I require date, hours, and minutes. When testing values in SQL Developer (Oracle) to figure out acceptable formats, I keep running into this behavior:

select to_date('2010-11-15 12:21:00', 'yyyy/mm/dd hh:mi:ssam') from dual

15-NOV-10

Clearly, I specify I want time, but it just doesn't agree with me. I've been stuck on this issue way too long.

In short, how do I format a SQL Server datetime into a format that Oracle's to_date function will accept, and how do I make that function properly show date and time?

Answer 1

SET @FOO = (SELECT * ...

I frown at that because you're assigning the result of a query, and * (all columns) as well, into a variable?

Anyway, a_horse_with_no_name has sort of given you the format of the datetime literal you need to present to Oracle, being timestamp .

SET @query = 'SELECT * FROM Table1
              WHERE date_revised > timestamp ''2010-11-15 12:21:00''';

(I leave the exercise of producing the YYYY-MM-DD HH:MM:SS text to you)

Answer 2

Assuming @mydate is DATETIME the trick is to change the datetime to a string with a known format on SQL Server and use the format to change it back to a DATE on Oracle.

SET @foo = 'SELECT * from OPENQUERY(' + @LinkedServer +
', ''SELECT *
     FROM Table1
WHERE date_revised > TO_DATE('''''
                     + CONVERT( varchar( max ), @myDate, 120 )
                     + ''''', ''''yyyy-mm-dd hh24:mi:ss'''') '')'

The 120 part tells SQL Server to format the date into a string with the format yyyy-mm-dd hh24:mi:ss, the format part tells Oracle how to turn the string back into a date.

Answer 3

I came up with my own solution since Oracle was being uncooperative with me. I basically take the DATEPARTS of everything and construct my own date-string in the same format in oracle. Thanks for your input all. When I get more time, I will try to get this working as it should. This bandaid will do for now.

DECLARE @year varchar(4),
    @month varchar(3),
    @day varchar(2),
    @hour varchar(2),
    @meridian varchar(2),
    @minute varchar(2),
    @second varchar(2),
    @date smalldatetime,
    @OracleTime varchar(50);

SET @date = (SELECT MAX(Processed) FROM MES_CAPP.Signoff)
SET @year = YEAR(@date)
SET @month = DATENAME(m,@date)
SET @day = DAY(@date)
-------------------------------------------------------------------------
IF (DATEPART(hh, @date) >= 12)
BEGIN
    SET @hour = DATEPART(hh, DATEADD(hh, -12, @date))
    SET @meridian = 'PM'
END
ELSE
BEGIN
    SET @hour = DATEPART(hh, @date)
    SET @meridian = 'AM'
END

SET @minute = DATEPART(MINUTE, @date)
SET @second = '00'

SET @OracleTime = @day + '-'  + @month + '-' + @year + ' ' + @hour + ':' + @minute + ':' + @second + ' ' + @meridian

Answer 4

I took Jeff's answer and wrapped it in a function that returns a to_date string.

    CREATE FUNCTION [dbo].[fnOracleTo_DateStringFromMsSqlDate] 
(
    @InputDate datetime
)
RETURNS varchar(100)
AS
BEGIN

    DECLARE @year varchar(4),
        @month varchar(3),
        @day varchar(2),
        @hour varchar(2),
        @minute varchar(2),
        @second varchar(2),
        @date smalldatetime,
        @OracleTime varchar(50),
        @returnString varchar(100)

    SET @year = YEAR(@InputDate)
    SET @month = Month(@InputDate)
    SET @day = DAY(@InputDate)
    -------------------------------------------------------------------------

        SET @hour = DATEPART(HH, @InputDate)

    SET @minute = DATEPART(MINUTE, @InputDate);
    SET @second = datepart(SECOND, @InputDate);

    SET @OracleTime = @day + '-'  + @month + '-' + @year + ' ' + @hour + ':' + @minute + ':' + @second ;
    set @returnString = 'to_date(' + char(39) +  @OracleTime  + char(39) + ',' + char(39) +  'DD-MM-YYYY HH24:MI:SS' + char(39) + ')'

    return @returnString;
END