How do I do batch upserts in SQL Server?

Question

I'm using the MERGE statement to upsert rows in an sql server 2008 database. However, my sproc is a single-row operation, whereas in fact I'd prefer to batch these. Is this even possible and, if so, how do I do it?

Answer 1

Can you use Table-Valued Parameters in your proc? Take a look here http://www.sommarskog.se/arrays-in-sql-2008.html#TVP_in_TSQL to get some ideas

Then in the proc you can use MERGE against the TVP

Answer 2

i have created a proc called 'upsert' which takes a source table name, target table name, fields to join on, and fields to update (fields are separated by commas) and then does the merge dynamically.

code is below.

    CREATE proc [common].[upsert](@source nvarchar(100), @target nvarchar(100), @join_field nvarchar(100), @fields nvarchar(200))
    as

    --@source is the table name that holds the rows that you want to either update or insert into @target table
    --@join_field is the 1 field on which the two tables will be joined...you can only join on 1 field right now!
    --@fields are the comma separated fields that will either be updated or inserted into @target. They must be the same name in @source and @target


    declare @sql nvarchar(max)

    set @sql = '
        merge '+ @target +' as target
        using '+ @source +' as source
        on target.'+ @join_field +' = source.'+ @join_field +'
        when matched then
            update set
                ' + common.upsert_update_fields_string_builder('source', 'target', @fields) + '
        when not matched then
            insert ('+ @join_field +', '+ @fields +')
            values (source.'+ @join_field +',' + common.upsert_insert_fields_string_builder('source', @fields) +');
    '


    exec(@sql)







    CREATE function [common].[upsert_insert_fields_string_builder](@source nvarchar(100), @fields nvarchar(200))
    returns nvarchar(1000)
    as
    begin
    declare @string nvarchar(max)

    select @string = coalesce(
            @string + ',' + @source + '.' + items,        
            @source +'.' + items) 
    from common.split_string(@fields,',')

    return @string  
    end







    CREATE function [common].[upsert_update_fields_string_builder](@source nvarchar(100), @target nvarchar(100), @fields nvarchar(200))
    returns nvarchar(1000)
    as
    begin
    declare @string nvarchar(max)

    select @string = coalesce(
            @string + ', '+ @target + '.' + items + '=' + @source + '.' + items,        
            ''+ @target +'.' + items + '='+ @source +'.' + items) 
    from common.split_string(@fields,',')

    return @string  
    end