Question

我有一张这样的表：

// numbers
+---------+------------+
|    id   |    numb    |
+---------+------------+
| int(11) |   bit(10)  |
+---------+------------+
| 1       | 0000000001 |
| 2       | 0000000101 |
| 3       | 0000000000 |
| 4       | 0000001011 |
+---------+------------+

当我获取numb列时，结果将如下：

// Query
mysql> SELECT numb FROM numbers WHERE id = 2

// Fetching by PHP (pdo)
$result = $stm->fetch();
$numb   = $result['numb'];
echo $numb;
//=> 5

如您所见，最终结果为5。虽然我想将这个确切的值作为字符串，例如0000000101。我怎么能这样做？

Answer 1

您可以使用decbin()功能和sprintf用于预先挂起的零

0000000101

输出：

12 - 0000001100
26 - 0000011010

来自您的评论：

$numb

<强> UPDATE1：

您可以像这样分配$numb = sprintf("%010d",decbin($result['numb']));变量：

CREATE TABLE person  
(   id             NUMBER(9,0)    NOT NULL  
  , name           VARCHAR2(30)   NOT NULL  
  , gender         VARCHAR2(1)    NOT NULL  
  , fatherid       NUMBER(9,0)    NULL  
  , motherid       NUMBER(9,0)    NULL  
  , father_gender  VARCHAR2(1)    GENERATED ALWAYS AS ('M') VIRTUAL  
  , mother_gender  VARCHAR2(1)    GENERATED ALWAYS AS ('F') VIRTUAL  
  , CONSTRAINT     ck_person_gender    CHECK (gender IN ('M', 'F'))  
  , CONSTRAINT     pk_person           PRIMARY KEY (id)  
  , CONSTRAINT     uk_person           UNIQUE (id, gender)  
  , CONSTRAINT     fk_person_father    FOREIGN KEY (fatherid, father_gender)  
                   REFERENCES person (id, gender) ON DELETE CASCADE  
  , CONSTRAINT     fk_person_mother    FOREIGN KEY (motherid, mother_gender)  
                   REFERENCES person (id, gender) ON DELETE CASCADE  
) TABLESPACE users;

Answer 2

这完全按照您的要求使用SQL：

使用CONV()和LPAD()：

LPAD(CONV(id,10,2),10,0)

以下是SQLFiddle

如何以二进制形式获取BIT（...）数据类型列的值？

2 个答案: