How to extract JSON object field in PostgreSQL?
Extracts n ‘th element of JSON array (array elements are indexed from zero, but negative integers count from the end). Extracts JSON object field with the given key. Extracts n ‘th element of JSON array, as text. Extracts JSON object field with the given key, as text.
What are the JSON types supported in PostgreSQL?
For details on JSON types supported in PostgreSQL, see Section 8.14. 9.16.1. Processing and Creating JSON Data Table 9.44 shows the operators that are available for use with JSON data types (see Section 8.14 ).
How to suppress jsonpath errors in PostgreSQL?
The jsonpath operators @? and @@ suppress the following errors: missing object field or array element, unexpected JSON item type, datetime and numeric errors. The jsonpath -related functions described below can also be told to suppress these types of errors.
When to use the cast function in PostgreSQL?
Otherwise, if there is a cast from the SQL data type to json, the cast function will be used to perform the conversion; [a] otherwise, a scalar JSON value is produced. For any scalar other than a number, a Boolean, or a null value, the text representation will be used, with escaping as necessary to make it a valid JSON string value.
Are there any comparison operators for JSON in PostgreSQL?
In addition, the usual comparison operators shown in Table 9.1 are available for jsonb, though not for json. The comparison operators follow the ordering rules for B-tree operations outlined in Section 8.14.4. Extracts n ‘th element of JSON array (array elements are indexed from zero, but negative integers count from the end).
How to concatenate two JSON objects in PostgreSQL?
The || operator concatenates two JSON objects by generating an object containing the union of their keys, taking the second object’s value when there are duplicate keys. All other cases produce a JSON array: first, any non-array input is converted into a single-element array, and then the two arrays are concatenated.
Which is the best documentation for PostgreSQL JSON?
PostgreSQL: Documentation: 12: 9.15. JSON Functions and Operators Supported Versions: Current ( 13 ) / 12 / 11 / 10 / 9.6 9.15. JSON Functions and Operators Chapter 9. Functions and Operators 9.15. JSON Functions and Operators 9.15.1. Processing and Creating JSON Data 9.15.2. The SQL/JSON Path Language the SQL/JSON path language