在MySQL中使用IsNull时参数不正确

Question

我一直在尝试使用该IsNull()函数来确保字段的值.

SELECT crawled.id,
       IsNull(sranking.score,0) as Score,
       crawled.url,
       crawled.title,
       crawled.blurb
FROM crawled
    LEFT JOIN sranking ON crawled.id = sranking.sid
WHERE crawled.body LIKE '%".$term."%'
ORDER BY Score DESC LIMIT " . $start . "," . $c

但我收到错误消息:

调用本机函数'IsNull'时参数计数不正确

有人有什么想法吗？我是MySQL的新手.

Answer 1

ISNULL测试传递的表达式是否为NULL.如上所述,你需要的是IFNULL或COALESCE xyld.

SELECT crawled.id, IFNULL(sranking.score, 0) as Score, ...