MySQL AI User Guide
This topic describes how to generate recommendations for similar users.
For known users, the output includes a list of predicted users that have similar behavior and taste.
The predictions are expressed in cosine similarity, and range from 0, very dissimilar, to 1, very similar.
For a new user, there is no information to provide a prediction. This generates an error.
Review and complete the following tasks:
            When you run
            ML_PREDICT_TABLE
            to generate similar user recommendations, a default value of
            three similar users are recommended. To change this value,
            set the topk parameter.
          
You have the option to include item and user metadata when generating predictions. These steps include that metadata in the command to generate predictions.
                If not already done, load the model. You can use the
                session variable for the model that is valid for the
                duration of the connection. Alternatively, you can use
                the model handle previously set. For the option to set
                the user name, you can set it to
                NULL.
              
The following example uses the session variable.
mysql> CALL sys.ML_MODEL_LOAD(@model, NULL);
The following example uses the model handle.
mysql> CALL sys.ML_MODEL_LOAD('recommendation_use_case', NULL);
                Make predictions for the test dataset by using the
                ML_PREDICT_TABLE
                routine.
              
mysql> CALL sys.ML_PREDICT_TABLE(table_name, model_handle, output_table_name), [options]);
                Replace table_name,
                model_handle, and
                output_table_name with your
                own values. Add options as
                needed.
              
You have the option to specify the input table and output table as the same table if specific conditions are met. See Input Tables and Output Tables to learn more.
                The following example runs
                ML_PREDICT_TABLE
                on the testing dataset previously created and sets the
                topk parameter to 2, so only two
                similar users are generated.
              
mysql> CALL sys.ML_PREDICT_TABLE('recommendation_data.testing_dataset', @model, 'recommendation_data.similar_user_recommendations', 
                                  JSON_OBJECT('recommend', 'users_to_users', 
                                              'topk', 2, 
                                              'user_metadata', JSON_OBJECT('table_name', 'recommendation_data.users'), 
                                              'item_metadata', JSON_OBJECT('table_name', 'recommendation_data.items')));Where:
                    recommendation_data.testing_dataset
                    is the fully qualified name of the input table that
                    contains the data to generate predictions for
                    (database_name.table_name).
                  
                    @model is the session variable
                    for the model handle.
                  
                    recommendation_data.similar_user_recommendations
                    is the fully qualified name of the output table with
                    recommendations
                    (database_name.table_name).
                  
                    JSON_OBJECT('recommend', 'users_to_users',
                    'topk', 2) sets the recommendation task to
                    recommend similar users. A maximum of two similar
                    users is set.
                  
                    'user_metadata', JSON_OBJECT('table_name',
                    'recommendation_data.users') specifies the
                    table that has user metadata to use when generating
                    predictions.
                  
                    'item_metadata', JSON_OBJECT('table_name',
                    'recommendation_data.items') specifies the
                    table that has item metadata to use when generating
                    predictions.
                  
Query the output table to review the top two similar users generated for each user in the output table.
mysql> SELECT * from similar_user_recommendations;
+---------+---------+--------+---------------------------------------------------------------------------+
| user_id | item_id | rating | ml_results                                                                |
+---------+---------+--------+---------------------------------------------------------------------------+
| 1       | 2       |    4.0 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.7922, 0.7238]}}  |
| 1       | 4       |    7.0 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.7922, 0.7238]}}  |
| 1       | 6       |    1.5 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.7922, 0.7238]}}  |
| 1       | 8       |    3.5 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.7922, 0.7238]}}  |
| 10      | 18      |    1.5 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.6827, 0.5943]}}  |
| 10      | 2       |    6.5 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.6827, 0.5943]}}  |
| 10      | 5       |    3.0 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.6827, 0.5943]}}  |
| 10      | 6       |    5.5 | {"predictions": {"user_id": ["3", "5"], "similarity": [0.6827, 0.5943]}}  |
| 2       | 1       |    5.0 | {"predictions": {"user_id": ["7", "9"], "similarity": [0.6473, 0.5746]}}  |
| 2       | 3       |    8.0 | {"predictions": {"user_id": ["7", "9"], "similarity": [0.6473, 0.5746]}}  |
| 2       | 5       |    2.5 | {"predictions": {"user_id": ["7", "9"], "similarity": [0.6473, 0.5746]}}  |
| 2       | 7       |    6.5 | {"predictions": {"user_id": ["7", "9"], "similarity": [0.6473, 0.5746]}}  |
| 3       | 18      |    7.0 | {"predictions": {"user_id": ["1", "10"], "similarity": [0.7922, 0.6827]}} |
| 3       | 2       |    3.5 | {"predictions": {"user_id": ["1", "10"], "similarity": [0.7922, 0.6827]}} |
| 3       | 5       |    6.5 | {"predictions": {"user_id": ["1", "10"], "similarity": [0.7922, 0.6827]}} |
| 3       | 8       |    2.5 | {"predictions": {"user_id": ["1", "10"], "similarity": [0.7922, 0.6827]}} |
| 4       | 1       |    5.5 | {"predictions": {"user_id": ["9", "7"], "similarity": [0.9764, 0.9087]}}  |
| 4       | 3       |    8.5 | {"predictions": {"user_id": ["9", "7"], "similarity": [0.9764, 0.9087]}}  |
| 4       | 6       |    2.0 | {"predictions": {"user_id": ["9", "7"], "similarity": [0.9764, 0.9087]}}  |
| 4       | 7       |    5.5 | {"predictions": {"user_id": ["9", "7"], "similarity": [0.9764, 0.9087]}}  |
| 5       | 12      |    5.0 | {"predictions": {"user_id": ["8", "1"], "similarity": [0.992, 0.7238]}}   |
| 5       | 2       |    7.0 | {"predictions": {"user_id": ["8", "1"], "similarity": [0.992, 0.7238]}}   |
| 5       | 4       |    1.5 | {"predictions": {"user_id": ["8", "1"], "similarity": [0.992, 0.7238]}}   |
| 5       | 6       |    4.0 | {"predictions": {"user_id": ["8", "1"], "similarity": [0.992, 0.7238]}}   |
| 6       | 3       |    6.0 | {"predictions": {"user_id": ["4", "9"], "similarity": [0.5695, 0.4862]}}  |
| 6       | 5       |    1.5 | {"predictions": {"user_id": ["4", "9"], "similarity": [0.5695, 0.4862]}}  |
| 6       | 7       |    4.5 | {"predictions": {"user_id": ["4", "9"], "similarity": [0.5695, 0.4862]}}  |
| 6       | 8       |    7.0 | {"predictions": {"user_id": ["4", "9"], "similarity": [0.5695, 0.4862]}}  |
| 7       | 1       |    6.5 | {"predictions": {"user_id": ["9", "4"], "similarity": [0.9738, 0.9087]}}  |
| 7       | 4       |    3.0 | {"predictions": {"user_id": ["9", "4"], "similarity": [0.9738, 0.9087]}}  |
| 7       | 5       |    5.5 | {"predictions": {"user_id": ["9", "4"], "similarity": [0.9738, 0.9087]}}  |
| 7       | 9       |    8.0 | {"predictions": {"user_id": ["9", "4"], "similarity": [0.9738, 0.9087]}}  |
| 8       | 2       |    8.5 | {"predictions": {"user_id": ["5", "1"], "similarity": [0.992, 0.6356]}}   |
| 8       | 4       |    2.5 | {"predictions": {"user_id": ["5", "1"], "similarity": [0.992, 0.6356]}}   |
| 8       | 6       |    5.0 | {"predictions": {"user_id": ["5", "1"], "similarity": [0.992, 0.6356]}}   |
| 8       | 9       |    3.5 | {"predictions": {"user_id": ["5", "1"], "similarity": [0.992, 0.6356]}}   |
| 9       | 1       |    5.0 | {"predictions": {"user_id": ["4", "7"], "similarity": [0.9764, 0.9738]}}  |
| 9       | 3       |    8.0 | {"predictions": {"user_id": ["4", "7"], "similarity": [0.9764, 0.9738]}}  |
| 9       | 7       |    2.5 | {"predictions": {"user_id": ["4", "7"], "similarity": [0.9764, 0.9738]}}  |
| 9       | 8       |    5.5 | {"predictions": {"user_id": ["4", "7"], "similarity": [0.9764, 0.9738]}}  |
+---------+---------+--------+---------------------------------------------------------------------------+
40 rows in set (0.0414 sec)
                Review the recommended similar users in the
                ml_results column next to
                user_id. For example, for user 1,
                users 3 and 5 are the top users predicted to be most
                similar. Review the similarity values in the
                ml_results column next to
                similarity to review the how similar
                each user is. For example, user 3 has a similarity value
                of 0.7922 to user 1, and user 5 has a similarity value
                of 0.7238.
              
Learn how to generate different types of recommendations:
Learn how to Score a Recommendation Model.