oracle一页显示15行,oracle rownum分页与显示记录小测
同事問及關于rownum表記錄不顯示問題,經查閱官方手冊,附上測試筆記:
SQL> insert into t_rownum select level from dual connect by level<=5;
5 rows inserted
SQL> commit;
Commit complete
SQL> select * from t_rownum;
A
---------------------------------------
1
2
3
4
5
SQL> select * from t_rownum where rownum>0;
A
---------------------------------------
1
2
3
4
5
SQL> select * from t_rownum where rownum>=0;
A
---------------------------------------
1
2
3
4
5
SQL> select * from t_rownum where rownum>=1;
A
---------------------------------------
1
2
3
4
5
SQL> select * from t_rownum where rownum>=2;
A
---------------------------------------
SQL> select * from t_rownum where rownum>2;
A
---------------------------------------
SQL>
官方手冊源語:
Conditions testing for ROWNUM values greater than a positive integer are always false. For example, this query returns no rows:SELECT *
FROM employees
WHERE ROWNUM > 1;
The first row fetched is assigned a ROWNUM of 1 and makes the condition false. The second row to be fetched is now the first row and is also assigned a ROWNUM of 1 and makes the condition false. All rows subsequently fail to satisfy the condition, so no rows are returned.
You can also use ROWNUM to assign unique values to each row of a table, as in this example:UPDATE my_table
SET column1 = ROWNUM;總而述之:oracle會對提取的記錄一一比較是否符合where條件,故不會顯示記錄
總結
以上是生活随笔為你收集整理的oracle一页显示15行,oracle rownum分页与显示记录小测的全部內容,希望文章能夠幫你解決所遇到的問題。
- 上一篇: 长城在哪
- 下一篇: oracle bbed 使用,Oracl