mysql - 如何从 MySql 中的结果集中将两行连接成字符串？

Question

基本上这是我的mysql查询：

select distinct(shipment_tag) from ir_shipment_registry where shipment_id = '2020111'

和结果集：

| shipment_tag |
+--------------+
|  Truck       |
|  Equipment   |
|              |

如何将两个结果集连接到字符串中，以便将其分配给变量？我试过了

SET @purchasetype = (select distinct(shipment_tag) from ir_shipment_registry where shipment_id = '2020111')

但它返回并且错误说：Subquery returns more than 1 row.

我想在我的变量中添加一些东西，例如：@purchasetype = "Truck, Equipment".

标签： mysql

Answer 1

也许GROUP_CONCAT在这里使用：

SET @purchasetype = (SELECT GROUP_CONCAT(shipment_tag SEPARATOR ', ') FROM ir_shipment_registry WHERE shipment_id = '2020111');