SQL 服务器：将数据类型 nvarchar 转换为十进制时出错

Question

The following piece of code is opening a JSON message and is inserting the value that corresponds to the '$.disgust' field on the JSON message on the post_metric_score table. It works fine in general except when the value is something like that:

"disgust": 5.6780936574796215e-05. 

The error that I get is

Error converting data type nvarchar to decimal

INSERT INTO [Database].[post_metric_score] ([post_id], [metric_id], [score])
    SELECT @post_id, 4, [score]
    FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
         WITH ([score] DECIMAL(12, 8) '$.disgust') 

I tried to add a convert statement in the SELECT statement but it doesn't work eg

SELECT @post_id, 6, CONVERT(DECIMAL(12,8), [score]) AS [score] 

Any ideas of what I am doing wrong?

Answer 1

Try retrieving the value as a string and using try_convert() :

INSERT INTO [Database].[post_metric_score]([post_id], [metric_id], [score])
    SELECT @post_id, 4, try_convert(decimal(12, 8), try_convert(float, [score]))
    FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
        WITH ([score] VARCHAR(255) '$.disgust') ;

Or use a float directly:

INSERT INTO [Database].[post_metric_score]([post_id], [metric_id], [score])
    SELECT @post_id, 4, try_convert(decimal(12, 8), try_convert(float, [score]))
    FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
        WITH ([score] float '$.disgust') ;