Question

我正在编写一个Oracle函数，我试图将varchar（4）值增加，就像它是一个数字一样，并且如果它最大化则将其翻转回来开始。因此，如果前一个值为0001，我将其设置为0002.如果它的9999设置为0001。

SELECT the_field INTO some_variable
  FROM my_table
  WHERE ID = <id I use>;

  IF (some_variable= '9999')
    some_variable:= '0001';
  ELSE
    --Not sure here--
  END IF;

我在ELSE语句中做什么来增加？

Answer 1

这似乎是一件奇怪的事情，尤其是因为它似乎回复了一次修改数据的人 - 如果你在某个时刻更新了该ID的行，你可以选择更新来锁定我猜想。

但是假设您想要坚持使用此模型，您可以使用<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <a href="#" id="start">Click To Start</a> <a href="#" id="stop">Click To Stop</a> <br>进行翻转：

mod()

但是，在9999之后，它会将0000作为下一个值。如果您想跳过该值并转到0001，则可以添加select to_char(mod(to_number(the_field, '9999') + 1, 10000), 'FM0000') from my_table where id = some_id;电话：

greatest()

包含一些示例数据的快速演示：

select to_char(greatest(mod(to_number(the_field, '9999') + 1, 10000), 1), 'FM0000')
from my_table
where id = some_id;

Answer 2

只是要添加上面的答案，你需要输入一个LPAD函数来将前导零添加到增加的数字。

DDL和DML：

create table my_table
(
    ID          varchar2(4)
   ,the_field   varchar2(100)
);

insert into my_table (ID, the_field) values(1, '0001');
insert into my_table (ID, the_field) values(2, '0002');
insert into my_table (ID, the_field) values(3, '9998');
insert into my_table (ID, the_field) values(4, '9999');
insert into my_table (ID, the_field) values(5, '0014');
insert into my_table (ID, the_field) values(6, '0903');
insert into my_table (ID, the_field) values(7, '2108');

commit;

来自my_table的数据：

--- ----------
ID  THE_FIELD
--- ----------
1   0001
2   0002
3   9998
4   9999
5   0014
6   0903
7   2108

PL / SQL块：（P.S.我将SELECT..INTO语句移动到Cursor，所以我可以循环这个例子的所有数据）

SET SERVEROUTPUT ON;
declare

    new_some_variable varchar2(100);

    Cursor c1 is
    SELECT  id,
            the_field some_variable
    FROM    my_table;

begin

    for c_1 in c1 loop

    DBMS_OUTPUT.PUT_LINE('The ID is: '||c_1.ID);
    DBMS_OUTPUT.PUT_LINE('Value of Some_Variable before Update: '||c_1.some_variable);

        IF (c_1.some_variable = '9999') then    
            new_some_variable := '0001';        
        ELSE

            new_some_variable := LPAD(TO_NUMBER(c_1.some_variable)+1, 4, '000');

        END IF;

    DBMS_OUTPUT.PUT_LINE('New Value of Some_Variable After Update: '||new_some_variable);

    end loop;

END;

输出：

The ID is: 1
Value of Some_Variable before Update: 0001
New Value of Some_Variable After Update: 0002
The ID is: 2
Value of Some_Variable before Update: 0002
New Value of Some_Variable After Update: 0003
The ID is: 3
Value of Some_Variable before Update: 9998
New Value of Some_Variable After Update: 9999
The ID is: 4
Value of Some_Variable before Update: 9999
New Value of Some_Variable After Update: 0001
The ID is: 5
Value of Some_Variable before Update: 0014
New Value of Some_Variable After Update: 0015
The ID is: 6
Value of Some_Variable before Update: 0903
New Value of Some_Variable After Update: 0904
The ID is: 7
Value of Some_Variable before Update: 2108
New Value of Some_Variable After Update: 2109

希望有帮助！

Answer 3

您可以使用to_char和to_number

select  TO_CHAR(to_number(my_column, '9999')+1)  from dual

Answer 4

tmp$ python get-pip.py
Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581) - skipping
Requirement already up-to-date: pip in /usr/lib/python2.7/dist-packages

在oracle中增加varchar值

4 个答案: