This could save us from the decision of adding NoSQL solutions to our technology stack which could also add more complexity and additional costs. ConclusionĪs was mentioned in the previous article, in some cases, Postgres JSON types and functions can be good alternatives for NoSQL databases. Furthermore, the property in our entity that stores the JSON column does not have to be a complex object like JsonbConent in our examples. It does not have to be defined as a property in JSON type. You can query by any attribute which you want. With the posjsonhelper operator, you don't have this problem. That might be a problem if you assume that your JSON structure can be more dynamic and have an elastic structure not defined by any schema. And more importantly, you can not query by attribute if it is not mapped to the property in the JSON type. However, as you read at the beginning of the article, the native query support for JSON attributes is only allowed when the JSON class has properties with simple types. To see the difference between those operators, please check the Postgres documentation linked earlier. The jsonb_extract_path and jsonb_extract_path_text are wrappers for #> and #> operators. Why Use the posjsonhelper Library When Hibernate Has Some Support for JSON Attributes Queryīesides those two operators that support the array types mentioned above, the library has two additional useful operators. Jsonb_any_array_strings_exist(jsonb_extract_path(i1_0.jsonb_content,?),array)įor more examples of how to use numeric operators please check the demo dao object and dao tests. For the default setting these functions will have the implementation below. Posjsonhelper the library requires two custom SQL functions that will wrap those operators. That is why we need to wrap them, for example, in a custom SQL function. The operator above can not be used in HQL because of special characters. So generally if we have a JSON property that contains an array, then you can check if it contains the least of the elements that you are searching by.īesides executing native SQL queries, Hibernate 6 does not have support for the above operations. ?| - This checks if any of the strings in the text array exist as top-level keys or array elements.So generally if we have a JSON property that contains an array, then you can check if it contains all elements that you are searching by. ?&- This checks if all of the strings in the text array exist as top-level keys or array elements.The library supports a few Postgres JSON function operators, such as: The jsonb_extract_path_text is a Postgres function that is equivalent to the #> operator (please check the Postgres documentation linked earlier for more details). Jsonb_extract_path_text(i1_0.jsonb_content,?) like ? escape '' Public List findAllByStringValueAndLikeOperatorWithHQLQuery(String expression) ') īelow is an example of the same query presented at the beginning, but created with SQM components and criteria builder:
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