mysql非空字段计数

我想计算 mysql 中特定字段集有多少字段为空，我找到了一些示例，但它们都遍历整个表。

基本上我有8个字段，

listing_photo_1 到listing_photo_8，我想知道其中有多少个被填充。

I tried:

$result=mysql_query("SELECT count(*) as total from listings 
                       WHERE listing_photo_1 IS NOT NULL AND 
                             listing_photo_2 IS NOT NULL AND 
                             listing_photo_3 IS NOT NULL AND 
                             listing_photo_4 IS NOT NULL AND 
                             listing_photo_5 IS NOT NULL AND 
                             listing_photo_6 IS NOT NULL AND 
                             listing_photo_7 IS NOT NULL AND 
                             listing_photo_8 IS NOT NULL AND 
                             pmpid = '$pmpid'");

$data=mysql_fetch_assoc($result);
echo $data['total'];

结果是：1

为了澄清我期望的结果：

Listing_photo_1：已填满

Listing_photo_2：已填满

Listing_photo_3：已填满

Listing_photo_4：空

Listing_photo_5：空

Listing_photo_6：空

Listing_photo_7：空

Listing_photo_8：空`

结果应该是3

您的代码尝试计算所有字段不为空的行数。你应该使用is not null而不仅仅是not null.

要计算字段数量，请使用以下命令：

SELECT sum((listing_photo_1 IS NOT NULL) +
           (listing_photo_2 IS NOT NULL) +
           (listing_photo_3 IS NOT NULL) +
           (listing_photo_4 IS NOT NULL) +
           (listing_photo_5 IS NOT NULL) +
           (listing_photo_6 IS NOT NULL) +
           (listing_photo_7 IS NOT NULL) +
           (listing_photo_8 IS NOT NULL)
          ) as total
from listings
WHERE pmpid = '$pmpid';

计算行数：

SELECT count(*) as total
from listings
WHERE listing_photo_1 IS NOT NULL AND
      listing_photo_2 IS NOT NULL AND 
      listing_photo_3 IS NOT NULL AND 
      listing_photo_4 IS NOT NULL AND 
      listing_photo_5 IS NOT NULL AND 
      listing_photo_6 IS NOT NULL AND 
      listing_photo_7 IS NOT NULL AND 
      listing_photo_8 IS NOT NULL AND 
      pmpid = '$pmpid'";

EDIT:

如果它们为空，请使用如下逻辑：

SELECT sum((listing_photo_1 IS NOT NULL and listing_photo_1 <> '') +
           (listing_photo_2 IS NOT NULL and listing_photo_2 <> '') +
           (listing_photo_3 IS NOT NULL and listing_photo_3 <> '') +
           (listing_photo_4 IS NOT NULL and listing_photo_4 <> '') +
           (listing_photo_5 IS NOT NULL and listing_photo_5 <> '') +
           (listing_photo_6 IS NOT NULL and listing_photo_6 <> '') +
           (listing_photo_7 IS NOT NULL and listing_photo_7 <> '') +
           (listing_photo_8 IS NOT NULL and listing_photo_8 <> '')
          ) as total
from listings
WHERE pmpid = '$pmpid';