将数据从 JSON 插入数据库 table 时避免使用多个 INSERT 语句

Question

我在 SQL 服务器上编写了一个存储过程，它将以下内容作为输入 JSON post:

{"sentiment_results": {"polarity": -0.6, "subjectivity": 0.7, "emotions": {"anger": 0.08296050131320953, "disgust": 0.00219865539111197, "fear": 0.07708118110895157, "joy": 0.757244884967804, "surprise": 0.027166856452822685, "sadness": 0.05334791541099548}}, "sentiment_time": "2020-08-04T16:43:47.141948"}

...并使用以下脚本在数据库 table 中输入数据（post_metric_score table -> 每个数据点一行）

         INSERT INTO [STAGING].[post_metric_score]([post_id],[metric_id],[score])
            SELECT @post_id, 1, try_convert(decimal(12, 8), [score])
            FROM OPENJSON(@postJson, '$.sentiment_results')
                WITH ([score] FLOAT '$.polarity')

            INSERT INTO [STAGING].[post_metric_score]([post_id],[metric_id],[score])
            SELECT @post_id, 2, try_convert(decimal(12, 8), [score])
            FROM OPENJSON(@postJson, '$.sentiment_results')
                WITH ([score] FLOAT '$.subjectivity')

            INSERT INTO [STAGING].[post_metric_score]([post_id],[metric_id],[score])
            SELECT @post_id, 3, try_convert(decimal(12, 8), [score])
            FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
                WITH ([score] FLOAT '$.anger')

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

            INSERT INTO [STAGING].[post_metric_score]([post_id],[metric_id],[score])
            SELECT @post_id, 5, try_convert(decimal(12, 8), [score])
            FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
                WITH ([score] FLOAT '$.fear')

            INSERT INTO [STAGING].[post_metric_score]([post_id],[metric_id],[score])
            SELECT @post_id, 6, try_convert(decimal(12, 8), [score])
            FROM OPENJSON(@postJson, '$.sentiment_results.emotions')
                WITH ([score] FLOAT '$.joy')

该脚本工作正常，但它使用了很多 CPU，因为每个 JSON post.[=14= 运行将相同的插入查询插入 6 次]

有没有办法简化上面的脚本，这样就不必多次运行插入语句？

Answer 1

您可以打开 JSON 一次，获取您想要的列并使用 apply 取消透视。这是一个包含两列的示例：

INSERT INTO [STAGING].[post_metric_score]([post_id], [metric_id], [score])
    SELECT @post_id, v.metric_id, try_convert(decimal(12, 8), v.score)
    FROM OPENJSON(@postJson, '$.sentiment_results')
         WITH (polarity FLOAT '$.polarity',
               subjectivity FLOAT '$.subjectivity'
              ) as o CROSS APPLY
         (VALUES (1, o.polarity), (2, o.subjectivity)
         ) v(metric_id, score);

所有列：

INSERT INTO [STAGING].[post_metric_score]([post_id], [metric_id], [score])
    SELECT @post_id, v.metric_id, try_convert(decimal(12, 8), v.score)
    FROM OPENJSON(@postJson, '$.sentiment_results')
         WITH (polarity FLOAT '$.polarity',
               subjectivity FLOAT '$.subjectivity',
               anger FLOAT '$.emotions.anger',
               disgust FLOAT '$.emotions.disgust',
               fear FLOAT '$.emotions.fear',
               joy FLOAT'$.emotions.joy'
              ) as o CROSS APPLY
         (VALUES (1, o.polarity), (2, o.subjectivity), (3, o.anger), (4, o.disgust), (5, o.fear), (6, o.joy)
         ) v(metric_id, score);

Here 是 SQL fiddle.

Answer 2

另一个选项是使用 JSON_VALUE()（注意，OPENJSON() 可能比使用 JSON_VALUE() 六次更快）：

INSERT INTO [STAGING].[post_metric_score]([post_id], [metric_id], [score])
SELECT @postId, [metric_id], TRY_CONVERT(decimal(12, 8), [score])
FROM (VALUES 
    (1, JSON_VALUE(@postJson, '$.sentiment_results.polarity')),
    (2, JSON_VALUE(@postJson, '$.sentiment_results.subjectivity')),
    (3, JSON_VALUE(@postJson, '$.sentiment_results.emotions.anger')),
    (4, JSON_VALUE(@postJson, '$.sentiment_results.emotions.disgust')),
    (5, JSON_VALUE(@postJson, '$.sentiment_results.emotions.fear')),
    (6, JSON_VALUE(@postJson, '$.sentiment_results.emotions.joy'))
) v ([metric_id], [score])

将数据从 JSON 插入数据库 table 时避免使用多个 INSERT 语句

Avoid using multiple INSERT statements when inserting data from JSON to database table

sql

sql-server

json

stored-procedures