postgre数据库json字段取值

student_info为json字段，内容为：

{"gradeId":"6","name":"京津冀","classNo":"3","schoolName":"第一实验小学","parentPhone":"13312345678"}

select

ROW_NUMBER() over(order by a.student_info->>'studentName') as serial_num,

a.student_info->>'name' as student_name,

a.student_info->>'parentPhone' as parent_phone,

a.student_info->>'schoolName' as school_name,

a.student_info->>'classNo' as class_no,

a.order_no order_no,

a.order_status order_status,

a.unit_price unit_price,

a.qty qty,

a.refund_qty refund_qty,

a.total_price total_price,

a.refund_amount refund_amount,

sm_store.name store_name

from sm_order_line a

inner join sm_store on a.store_id = sm_store.id

where a.order_status not in ('已退款','未支付','待支付')

and a.student_info->>'schoolName'='第一实验小学' and a.student_info->>'gradeId'='6' and a.student_info->>'classNo'='1'