MySQL AI User Guide
This topic describes how to generate recommendations for either ratings (recommendation model with explicit feedback) or rankings (recommendation model with implicit feedback). If generating a rating, the output predicts the rating the user will give to an item. If generating a ranking, the output is a ranking of the user compared to other users.
For known users and known items, the output includes the
predicted rating or ranking for an item for a given pair
of user_id
and
item_id
.
For a known user with a new item, the prediction is the global average rating or ranking. The routines can add a user bias if the model includes it.
For a new user with a known item, the prediction is the global average rating or ranking. The routines can add an item bias if the model includes it.
For a new user with a new item, the prediction is the global average rating or ranking.
Review and complete the following tasks:
Since the model you previously trained used explicit feedback, you generate ratings that the user is predicted to give an item. A higher rating means a better rating. If you train a recommendation model using implicit feedback, you generate rankings. A lower ranking means a better ranking. The steps below are the same for both types of recommendation models. See Recommendation Task Types to learn more.
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.
mysql> CALL sys.ML_PREDICT_TABLE('recommendation_data.testing_dataset', @model, 'recommendation_data.recommendations', NULL);
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.recommendations
is the fully qualified name of the output table with
predictions
(database_name.table_name
).
NULL
sets no options for the
routine.
Query the output table to review the predicted ratings that users give for each user-item pair.
mysql> SELECT * from recommendations;
+---------+---------+--------+-----------------------------------+
| user_id | item_id | rating | ml_results |
+---------+---------+--------+-----------------------------------+
| 1 | 2 | 4.0 | {"predictions": {"rating": 2.71}} |
| 1 | 4 | 7.0 | {"predictions": {"rating": 3.43}} |
| 1 | 6 | 1.5 | {"predictions": {"rating": 1.6}} |
| 1 | 8 | 3.5 | {"predictions": {"rating": 2.71}} |
| 10 | 18 | 1.5 | {"predictions": {"rating": 3.63}} |
| 10 | 2 | 6.5 | {"predictions": {"rating": 2.82}} |
| 10 | 5 | 3.0 | {"predictions": {"rating": 3.09}} |
| 10 | 6 | 5.5 | {"predictions": {"rating": 1.67}} |
| 2 | 1 | 5.0 | {"predictions": {"rating": 2.88}} |
| 2 | 3 | 8.0 | {"predictions": {"rating": 4.65}} |
| 2 | 5 | 2.5 | {"predictions": {"rating": 3.09}} |
| 2 | 7 | 6.5 | {"predictions": {"rating": 2.23}} |
| 3 | 18 | 7.0 | {"predictions": {"rating": 3.25}} |
| 3 | 2 | 3.5 | {"predictions": {"rating": 2.53}} |
| 3 | 5 | 6.5 | {"predictions": {"rating": 2.77}} |
| 3 | 8 | 2.5 | {"predictions": {"rating": 2.53}} |
| 4 | 1 | 5.5 | {"predictions": {"rating": 3.36}} |
| 4 | 3 | 8.5 | {"predictions": {"rating": 5.42}} |
| 4 | 6 | 2.0 | {"predictions": {"rating": 1.94}} |
| 4 | 7 | 5.5 | {"predictions": {"rating": 2.61}} |
| 5 | 12 | 5.0 | {"predictions": {"rating": 3.29}} |
| 5 | 2 | 7.0 | {"predictions": {"rating": 2.9}} |
| 5 | 4 | 1.5 | {"predictions": {"rating": 3.68}} |
| 5 | 6 | 4.0 | {"predictions": {"rating": 1.72}} |
| 6 | 3 | 6.0 | {"predictions": {"rating": 4.98}} |
| 6 | 5 | 1.5 | {"predictions": {"rating": 3.31}} |
| 6 | 7 | 4.5 | {"predictions": {"rating": 2.4}} |
| 6 | 8 | 7.0 | {"predictions": {"rating": 3.03}} |
| 7 | 1 | 6.5 | {"predictions": {"rating": 3.18}} |
| 7 | 4 | 3.0 | {"predictions": {"rating": 3.95}} |
| 7 | 5 | 5.5 | {"predictions": {"rating": 3.41}} |
| 7 | 9 | 8.0 | {"predictions": {"rating": 3.17}} |
| 8 | 2 | 8.5 | {"predictions": {"rating": 2.6}} |
| 8 | 4 | 2.5 | {"predictions": {"rating": 3.3}} |
| 8 | 6 | 5.0 | {"predictions": {"rating": 1.54}} |
| 8 | 9 | 3.5 | {"predictions": {"rating": 2.65}} |
| 9 | 1 | 5.0 | {"predictions": {"rating": 2.99}} |
| 9 | 3 | 8.0 | {"predictions": {"rating": 4.83}} |
| 9 | 7 | 2.5 | {"predictions": {"rating": 2.32}} |
| 9 | 8 | 5.5 | {"predictions": {"rating": 2.93}} |
+---------+---------+--------+-----------------------------------+
40 rows in set (0.0459 sec)
Review each user_id
and
item_id
pair and the respective
rating
value in the
ml_results
column. For example, in
the first row, user 1 is expected to give item 2 a
rating of 2.71.
The values in the rating
column refer
to the past rating the user_id
gave
to the item_id
. They are not relevant
to the values in ml_results
.
Alternatively, if you do not want to generate an entire
table of predicted ratings or rankings, you can run
ML_PREDICT_ROW
to specify a user-item pair.
mysql> SELECT sys.ML_PREDICT_ROW(input_data
, model_handle
), [options
]);
Replace input_data
and
model_handle
with your own
values. Add options
as
needed.
The following example runs
ML_PREDICT_ROW
and specifies user 2 and item 1.
mysql> SELECT sys.ML_PREDICT_ROW('{"user_id":"2", "item_id": "1"}', @model, NULL);
+-----------------------------------------------------------------------------------+
| sys.ML_PREDICT_ROW('{"user_id":"2", "item_id": "1"}', @model, NULL) |
+-----------------------------------------------------------------------------------+
| {"item_id": "1", "user_id": "2", "ml_results": {"predictions": {"rating": 2.88}}} |
+-----------------------------------------------------------------------------------+
1 row in set (0.8726 sec)
The predicted rating of 2.88 for the user-item pair is the same as the one in the output table previously created.
Learn how to generate different types of recommendations:
Learn how to Score a Recommendation Model.