DataSource Controls :: Loop Through The Records Of A Table?

im learning t-sql, infact i needed its while-loop to loop through records of a table, i found this code in some book:

[Code]....

i understand here that setting the rowcount variable to 1 will force the select statements to return only one record, do all above select statements return one record only?

if the underlined select statement returns one record everytime it is executed, isn't it supposed to return the same first record of the table everytime? is there a better way to loop through a table's records?