JSON_QUERY is a function in Oracle PL/SQL that is used to extract a JSON value from a JSON document. It takes two arguments – the JSON document and a JSON path expression that specifies the location of the value to be extracted.
The JSON document can be a JSON object, JSON array, or a scalar JSON value. The JSON path expression is a string that specifies the location of the value to be extracted using a syntax similar to XPath.
Here is the basic syntax of the JSON_QUERY function:
JSON_QUERY(json_document, json_path_expression)
The json_document is the JSON data to be queried and the json_path_expression is the JSON path to the data to be extracted.
For example, consider the following JSON document:
{
"employees":[
{"firstName":"John", "lastName":"Doe", "age":28},
{"firstName":"Jane", "lastName":"Doe", "age":24},
{"firstName":"Jim", "lastName":"Smith", "age":32}