mysql 使用 CONCAT、GROUP_CONCAT 嵌套查询出 json 格式数据
tb_factory表由 factory_code 和 factory_name 字段,查询出如下所示效果:
{
"factory_0001": "工厂1",
"factory_0002": "工厂2",
...
}
select sql:
SELECT
CONCAT(
"{",
GROUP_CONCAT( CONCAT(
CONCAT( "\"",factory_code,"\"" ),
":",
CONCAT( "\"",factory_name,"\"" )
) SEPARATOR ',' ),
"}"
) AS factory_codes
FROM
tb_factory