Paging overlap

Smart GWT Technical Q&A
1

I noticed that when the datasource asks for the second page it also asks for the last record from the first page.
This results in a mismatch in the number of records returned and the setTotalRows value.

The first page is from 0-75 and the second page is from 75-150, record 75 is fetched and shown twice in my grid. Shouldn’t this be 0-74 and 75-149 ?

The following error comes up because of this
16:31:08.445 [ERROR] [esos] 18:31:08.450:WARN:ResultSet:isc_ResultSet_0 (created by: isc_OID_3):fetchData callback: dsResponse.endRow set to:81. dsResponse.totalRows set to:80. endRow cannot exceed total dataset size. Clamping endRow to the end of the dataset (80).

2

The indices are inclusive at the beginning and exclusive at the end (like String.substring())

3

Ok, that makes sort of sense :slight_smile:
So when using Ms Sql ROW_NUMBER();
smartgwt page 1 ask for row 0-75 and is expecting DB row 1-75
smartgwt page 2 ask for row 75-150 and is expecting DB row 76-150

The paging query for SqlServer with the startRow and endRow provided by smartGWT is

SELECT * FROM (
  select  top {endRow}ROW_NUMBER() OVER(Order by [columnName] DESC) as Row, *
   from [tableName]) as page
WHERE  Row>{startRow}