SQL / PHP将字符串转换为float或int

Question

我有这个SQL查询..

select i.invoiceid as transactionid, i.date, i.total, 
'invoice' as transaction_type
from invoice

我在php中运行它并在foreach循环中回显总数，就像这样......

echo gettype($row['total']) . "<br/>";

并且所有总计都返回string

如何将我的sql查询中的i.total转换为int或float？

我试过

convert(int, i.total)

那并没有用:(

Answer 1

php将所有内容（不是数组/字典）作为字符串处理，除非您明确告诉它不要使用(int)$row['total']之类的内容。

http://php.net/manual/en/language.types.string.php#language.types.string.conversion

Answer 2

你可以尝试

select i.invoiceid as transactionid, i.date, CAST(i.total as int) as total, 
'invoice' as transaction_type
from invoice