2 Replies Latest reply: Jan 17, 2012 1:33 PM by Ashutosh Paliwal RSS

    When to use concatenated load and join load?

      Hi All,

       

      When to use concatenated load and join load?

       

      Regards,

      Attitude

        • When to use concatenated load and join load?
          Sunil Chauhan

          if you want to append data into one table then use concatenate

           

           

          if want to append data on basis of some key field use join

          • When to use concatenated load and join load?
            Ashutosh Paliwal

            Hi,

            Concatenation and Join are there for two totally different purpose.

            Concatenation is primarily used where we are getting same set of data from two different sources. for example one part of your data is coming from 1 table and another part of your data is coming from another table. So, you concatenate second table to 1st table and make 1 table from these 2 tables. It primary function is to add rows.

             

            Join is primarily used when based on any key you want to add more fields to your table.for example you have a key field in your table and to get description you join description table to your 1st table to get description in 1st table.

             

            The difference needs to be understood here is that concatenation does not do any search and just append the rows. while join will work on the base of search, it will search for the matching key values.

            for example we have 2 tables

             

             

            F1F2
            1112
            1213
            1314

             

            AND

             

             

            F1F2F3
            111213
            121314
            252556

             

            If we use concatenation then resulting table will be

             

            F1F2F3
            1112
            1213
            1314
            111213
            121314
            252556

             

             

            But if we do a join (suppose a full outer join) it will be like this.

             

            F1F2F3
            111213
            121314
            1314
            252556

             

            other joins in qlikview are inner join, left join, right join.

             

            So, as you see both of them are having a different result and are used in different scenrios.