Question

My database has alot of records recording the datetime various actions are or will be taken. In order to test the database properly, i want to move all of those further into the past, by 6 months, a year etc (As opposed to changing the system time). How can i achieve this with a stored procedure, paramaterised by number of days?

(Bonus points if you also include other date/time types such as datetime2)

To be clear, i’m looking for something that will update all columns in all tables dynamically.

Answer 1

Seems pretty simple…

CREATE PROCEDURE dbo.MoveDatesBack @NumberOfDays INT
AS BEGIN

   UPDATE dbo.YourTableNameHere
   SET SomeDateColum = DATEADD(DAY, @NumberOfDays, SomeDateColumn) 

   -- repeat the above statement for each table/column that you need to "move back"

END

Call this like so:

EXEC  dbo.MoveDatesBack @NumberOfDays = -30

or whatever you need …

The DATEADD function should work with any date type in SQL Server 2008 or newer – if you apply it to a DATETIME2, you’ll get back a new DATETIME2

But this seems too simple for Stackoverflow – what am I missing here??

Update: if you want to do this globally, across all tables and all date-related columns in your entire database – you can use a cursor-based approach something like this:

CREATE PROCEDURE dbo.MoveDatesBack @NumberOfDays INT
AS BEGIN
  DECLARE TableCursor CURSOR FAST_FORWARD 
  FOR
     SELECT t.Name, c.name
     FROM sys.columns c 
     INNER JOIN sys.tables t ON c.object_id = t.object_id
     INNER JOIN sys.types typ ON c.system_type_id = typ.system_type_id
     WHERE typ.system_type_id IN (40, 42, 43, 61)  
     -- 40 = date, 42 = datetime2, 43 = datetimeoffset, 61 = datetime

  DECLARE @TableName sysname, @ColumnName sysname

  OPEN TableCursor

  FETCH NEXT FROM TableCursor INTO @TableName, @ColumnName

  WHILE @@FETCH_STATUS = 0
  BEGIN
      DECLARE @Stmt NVARCHAR(999)

      SET @Stmt = 'UPDATE ' + QUOTENAME(@TableName) + 
                  ' SET ' + QUOTENAME(@ColumnName) + ' = DATEADD(DAY, ' + 
                  CAST(@NumberOfDays AS VARCHAR(10)) + ', ' + 
                  QUOTENAME(@ColumnName) + ')'

      -- PRINT @Stmt
      EXEC (@Stmt)

      FETCH NEXT FROM TableCursor INTO @TableName, @ColumnName
  END

  CLOSE TableCursor
  DEALLOCATE TableCursor
END

Use at your own risk! This will do massive updates all across your database! Be sure to have ample backups at hand to roll back in case something goes wrong!!

It’s pretty simplistic in that it assumes all tables are in the default schema – I don’t check and include schema information in this sample. Could be added – just make things a little bit more involved / more complicated.