[英]Oracle SQL ROWNUM and NEXTVAL
我创建了一个序列
CREATE SEQUENCE name_seq
START WITH 1
INCREMENT BY 1
NOCACHE
NOCYCLE;
然后在我的查询中使用它:
select Name, ROWNUM, name_seq.NEXTVAL
from myTable;
结果变成这样:
+----+------+-------+
|Name|ROWNUM|NEXTVAL|
+----+------+-------+
|A | 1| 1|
|B | 2| 2|
|C | 3| 3|
|D | 4| 4|
|E | 5| 5|
|F | 6| 6|
|G | 7| 7|
|H | 8| 8|
|I | 9| 9|
|J | 10| 10|
+----+------+-------+
从这开始,我希望输出是在要声明的数字之后使用序列的下一个值。 例如,我将使用4。输出应如下所示:
在第一轮中:
+----+------+-------+
|Name|ROWNUM|NEXTVAL|
+----+------+-------+
|A | 1| 1|
|B | 2| 1|
|C | 3| 1|
|D | 4| 1|
|E | 5| 2|
|F | 6| 2|
|G | 7| 2|
|H | 8| 2|
|I | 9| 3|
|J | 10| 3|
+----+------+-------+
然后在第二次运行中:
+----+------+-------+
|Name|ROWNUM|NEXTVAL|
+----+------+-------+
|A | 1| 4|
|B | 2| 4|
|C | 3| 4|
|D | 4| 4|
|E | 5| 5|
|F | 6| 5|
|G | 7| 5|
|H | 8| 5|
|I | 9| 6|
|J | 10| 6|
+----+------+-------+
尝试这个,
CREATE SEQUENCE name_test_seq
START WITH 1
INCREMENT BY 1
NOCACHE
NOCYCLE;
CREATE OR REPLACE FUNCTION get_next_val (p_num NUMBER) RETURN NUMBER
IS
BEGIN
IF p_num = 1 THEN
RETURN name_test_seq.NEXTVAL;
ELSE
RETURN name_test_seq.CURRVAL;
END IF;
END;
/
select rownum rown, get_next_val(MOD(rownum, :p_num))
from dual
connect by rownum <= 10
尝试这个 :
Select name,rownum,floor((name_seq.NEXTVAL-1)/4)+1 fl
from myTable
只需减去序列的最后一个数字。
with seq_cur_val as(
select last_number seq_cv
from user_sequences
where sequence_name='NAME_SEQ'
)
select name, rownum,
floor((name_seq.nextval-seq_cv)/4)+1
from myTable,seq_cur_val;
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