Nikolay Samokhvalov <[EMAIL PROTECTED]> writes: > I don't know the position of this row in result set, but I want to > retrieve 2 rows that are next to this one.
In general there is no such thing as "the row next to this one". SQL treats all data sets as unordered, up until the point where you do an explicit ORDER BY for display purposes. So your request is really meaningless unless you phrase it as "I want the rows that come immediately before and after this one in such-an-such an ordering". Once you do that, there is more than one way to solve the problem. For example, if the ordering you care about is on an indexed field, you could do something like SELECT * FROM tab WHERE foo > (SELECT foo FROM tab WHERE condition-to-select-reference-row) ORDER BY foo LIMIT 1 to get the following row, and SELECT * FROM tab WHERE foo < (SELECT foo FROM tab WHERE condition-to-select-reference-row) ORDER BY foo DESC LIMIT 1 to get the prior one (and if you really want just one query result, put these together with UNION ALL). Other solutions that come to mind involve cursors. You haven't told us enough about either the required ordering or the nature of the condition that defines "this row" to really say much about the best solution. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org