sql - How to Retrieve even rows in a table -

table a

 columna    ---------       b                c    :    :    z

here how select rows. i've written query

select * (select row_number()over(order no asc ) number      number   mod(number,2)=0)as

it isn't working.

try

select *      (   select *, row_number() on (order columna) rnum        tablea ) q  mod(rnum, 2) = 0

output:

 | no | rnum | |----|------| |  b |    2 | |  d |    4 | |  f |    6 |

here sqlfiddle demo

Bradly