This is in contrast to the more usual approach with SQL of defining a schema (a set of table rows and columns) for the data at storage time. A “schema”, in effect, gets defined on the fly at query time, by your specifying a given path. This design supports schemaless development.
It is used especially to retrieve fragments of a JSON document, typically a JSON object or array.įunction json_table projects some JSON data as a virtual table, which you can also think of as an inline view.īecause the path language is part of the query language, no fixed schema is imposed on the data. The former is used especially as a check constraint.įunction json_value selects a scalar value from some JSON data, as a SQL value.įunction json_query selects one or more values from some JSON data, as a SQL string representing the JSON values. You can use them to create, query, and operate on JSON data stored in Oracle Database.Ĭondition json_exists tests for the existence of a particular value within some JSON data.Ĭonditions is json and is not json test whether some data is well-formed JSON data. SQL/JSON functions and conditions, which completely support the path language and provide more power and flexibility than is available using the dot-notation syntax. This syntax is designed to be simple to use and to return JSON values whenever possible. An array step can follow each of the field names. Oracle provides two ways of querying JSON content:Ī dot-notation syntax, which is essentially a table alias, followed by a JSON column name, followed by one or more field names - all separated by periods (. More complex path expressions can contain filters and array indexes.
In its simplest form a path expression consists of one or more field names separated by periods (. To query particular JSON fields, or to map particular JSON fields to SQL columns, you can use the SQL/JSON path language. Because JSON data is stored in the database using standard data types ( VARCHAR2, BLOB, and CLOB), SQL queries work with JSON data the same as with any other database data.
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