在插入 SQL Server 表之前检测 JSON 参数中的重复 JSON 节点

Question

我想在将 JSON 中的重复节点插入 SQL Server 表之前检测它们。

我有这个存储过程，它采用这样的 JSON 参数：

CREATE PROCEDURE Core.myModelEditAction
    @OrganPersonID INT,
    @SalaryItems  NVARCHAR(2000),
    @AcceptLanguage NVARCHAR(50) = "fa"
AS
    DECLARE @Message NVARCHAR(MAX) = N''
BEGIN
    BEGIN TRY
        BEGIN TRANSACTION
            INSERT INTO Core.PersonSalary (OrganPersonID, SalaryItemID, Amount)
                SELECT @OrganPersonID, SalaryItemID, Amount
                FROM OPENJSON (@SalaryItems)
                     WITH (OrganPersonID int,
                           SalaryItemID int,
                           Amount int) 

如果@SalaryItems 有重复键，我想返回异常

如何检测

SELECT @OrganPersonID, SalaryItemID, Amount
FROM OPENJSON (@SalaryItems)

在我的代码中此表重复？

Answer 1

使用不带with 子句的OPENJSON()，以便返回原始的key、value 和type 列，例如：

declare @SalaryItems nvarchar(2000) = N'{
  "OrganPersonID": 1,
  "SalaryItemID": 1,
  "Amount": 1,
  "SalaryItemID": 1,
  "SalaryItemID": 1
}';

-- Detect duplicated keys...
select [key], count(1) as count
from openjson(@SalaryItems)
group by [key]
having count(1) > 1;

key           count
------------- -----
SalaryItemID      3