sql server 2008 - How can I get Month Difference from two dates which are stored in Table in the format YYYYMM -

my table has column date_period stores date in format yyyymm. want write query inserts date in date_period column in format yyyymm if there no entry till current month.

for example: date period has entry till october 2015 contain value 201510. want check , insert data till current month if not present. entries 201511, 201512, 201601

how can achieve this?

try way, may you

declare @v date= getdate() declare @currentdate varchar(10) set  @currentdate=convert(varchar(10), @v, 112) /*@currentdate string in format '20160129'*/ if not exists(select * table1  date_period=left(@currentdate,6)) begin  insert table1(date_period)values(left(@currentdate,6)) end 

try this

i think complete solution problem

declare @monthcount int declare @v date= getdate() declare @lastsavedmonth varchar(20)= (select max(date_period) table1) declare @lastsaveddate varchar(20)= @lastsavedmonth+''+right(convert(varchar, 100 + datepart(d,@v)), 2)  set @monthcount=datediff(month,@lastsaveddate,convert(varchar(10), @v, 112))  while @monthcount>=0         begin                 declare @dateofsavingmonth varchar(20)                 if(@monthcount=0)                     begin                     set @dateofsavingmonth=convert(varchar(10),@v,112)                     end                 else                    begin                      set @dateofsavingmonth=convert(varchar(10), dateadd(month,-@monthcount,@v),112)                    end                      if not exists(select * table1  date_period=left(@dateofsavingmonth,6))                     begin                      insert table1(date_period)values(left(@dateofsavingmonth,6))                     end                 set @monthcount =@monthcount-1         end