在Laravel Query Builder中合并来自不同数据库的查询 [英] Union queries from different databases in Laravel Query Builder
问题描述
我在两个不同的数据库中有两个相似的表.两个表都有一列带有日期,一列带有电子邮件地址.尽管列名不同.结果,我希望得到一个包含两个表中所有记录的结果.
I have two similar tables in two different databases. Both tables have a column with a date and one with email addresses. Though the column names are not the same. As result I want to have one result that contains all records from both tables.
所以我的第一步是:
$emails_1 = DB::connection('db1')->table('contacts_1')->select('mail_address AS email', 'date as created_at');
$emails_2 = DB::connection('db2')->table('contacts_2')->select('email', 'created_at');
所以现在我有两个结果,结果中的列名相等(电子邮件和created_at).
So now I have two results and the column names in the result are equal (email and created_at).
现在我想将结果合并在一起,所以我这样做:
Now I want to merge the results together, so I do:
$all_emails = $emails_1->union($emails_2);
这是我得到错误的地方:
And this is where I get the error:
找不到基本表或视图:1146表'db1.contacts_2'未找到 存在(SQL:(选择
mail_address
作为date
作为created_at
从contacts_1
)并集(从created_at
中选择contacts_2
))
Base table or view not found: 1146 Table 'db1.contacts_2' doesn't exist (SQL: (select
mail_address
asdate
ascreated_at
fromcontacts_1
) union (selectcreated_at
fromcontacts_2
))
因此,查询构建器似乎与不同的表混淆了.
So it seems that query builder gets confused with the diferente tables.
有人帮忙吗?
推荐答案
您不能使用其他连接,但是仍然可以明确地提供数据库名称:
You can't use different connections, but you still can do it providing the db name explicitly:
$q1 = DB::table('db1.contacts')
// where(..) or anything you need here
->select('mail_address as email', 'date as created_at');
$q2 = DB::table('db2.contacts')
// like above
->select('email', 'created_at');
$result = $q2->union($q1)->get();
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