![]() ![]() Value as follows (any other SQL value raises an error):Īn instance of a user-defined SQL object type If an input is not known to be JSON data, then it produces a JSON ![]() This applies regardless of whether the input represents a JSON scalar, object, or If, one way or another, an input is known to be JSON data then it is usedĮssentially as is to construct the result - it need not be processed in any way. Input data is the result of using function json_query or one of the Such cases using FORMAT JSON or treat … AS In some cases where an input is not of JSON type,Īnd you do not use FORMAT JSON or treat …ĪS JSON, Oracle nevertheless knows that the result is JSON data. JSON in this case otherwise, an error is raised.) This includes the case where the JSON type constructor is used. If the input data is of JSON type then it is used as is. JSON to it - the effect is the same as using FORMAT SQL string "true" to produce the JSON Boolean valueĮquivalently, if the input type is not JSON then you canĪpply SQL function treat with keywords AS Example 23-1 illustrates the use of FORMAT JSON to cause input When employed as an alternative syntax for json_object or json_array, you follow constructor JSON directly with braces ( ". The only difference in behavior is that the return data type when you use the constructor is always JSON (there is no RETURNING clause for the constructor). JSON and JSON type only if database initialization You can use constructor JSON with a special syntax as anĪlternative to using json_object and json_array when Then all fields are used, including any duplicates. Only one field of a set of duplicates is used, and which is used is WITHOUT UNIQUE KEYS is present) then no check for unique fields is If there are duplicates, an error is raised. If present, the returned JSON object is checked to be sure there are no duplicate field (available only for json_object and json_objectagg). That could be the case, for example, if a client applicationĬreated the input data and it did not ensure that each JSON string is represented by a Input data is also of JSON type and (2) you suspect that it is notĬompletely strict. STRICT when returning JSON type data if (1) the Is not checked for strict well-formedness. ![]() Specify STRICT then that input is used as is in the returned data it Type, and doing so can introduce a small performance penalty.Īn input and the returned data are both of JSON type, if you do not Specify STRICT when generating data of JSON data Generate an entire set of JSON documents using a single SQL statement, which allows theīecause only the generated documents are returned to aĬlient, network overhead is minimized: there is at most one round trip per document They always construct well-formed JSON documents.īy using SQL subqueries with the functions, you can Not suffer from such problems they are designed for the job of constructing JSON data from The SQL/JSON generation functions and constructor JSON do Represent multiple levels of one-to-many relationships then this technique can be quite Required, to collect all of the non-JSON data needed. Relationships as JSON data, multiple SELECT operations are often Inefficient, particularly due to network overhead. Reading non-JSON result sets from the database and usingĬlient-side application code to generate JSON data is typically quite Rules, which can result in generating incorrect JSON data. It is easy to overlook or misunderstand these In particular, there are a number of complex rules that mustīe respected concerning when and how to escape special characters, such as double Using string concatenation to generate JSONĭocuments is error prone. The order of array elements reflects the query result order, by default, but you can use the ORDER BY clause to impose array element order.Īlternatives to using the SQL/JSON generation functionsĪre generally error prone or inefficient. SQL/JSON function json_arrayagg constructs a JSON array by aggregating information from multiple rows of a grouped SQL query as the array elements. SQL/JSON function json_objectagg constructs a JSON object by aggregating information from multiple rows of a grouped SQL query as the object members. SQL/JSON function json_array constructs a JSON array from the results of evaluating its argument SQL expressions. SQL/JSON function json_object constructs JSON objects from the results of evaluating its argument SQL expressions. How the input values are used depends on their SQL data type. The input values are used to produce JSON object field–value pairs or JSON array elements. The SQL/JSON generation functions take SQL values as input and return a JSON object or array. Handling of Input Values For SQL/JSON Generation Functions.An overview is presented of JSON data generation: best practices, the SQL/JSON generation functions, a simple JSON constructor syntax, handling of input SQL values, and resulting generated data. ![]()
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