获得表中前一半的记录sql怎么写？

Question

如题

Answer 1

QL> select * from t;                                    IDX CNAME
--------------------------------------- ----------------------------------------
                                      1 a
                                      2 D
                                      3 c
                                      4 dSQL> select * from t where rownum<=(select count(1) from t)/2;                                    IDX CNAME
--------------------------------------- ----------------------------------------
                                      1 a
                                      2 D