出現(xiàn)exception: $concat only supports strings, not NumberInt32 原來$concat只能操作字符串,不支持?jǐn)?shù)字類型,解決辦法是用$substr 復(fù)制代碼代碼如下: $date形如'2013-10-13 11:17:18 UTC' 'fdate' => { '$concat' => [ {$substr=>['$date', 5, 2]}, '月', {$substr=>['$date', 8, 2]}, '日'] } $substr接受兩個(gè)參數(shù),一個(gè)是字...
www.dbjr.com.cn/article/515...htm 2025-6-9