[CALCITE-3010] In SQL parser, move JsonValueExpression into Expression

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.20.0
• Labels: pull-request-available
• Assignee: Hongze Zhang
• Reporter: Hongze Zhang
• Created: 17/Apr/19 09:52
• Updated: 24/Jun/19 15:01
• Resolved: 22/Apr/19 13:23

Description

Below is the syntax definition of JsonValueExpression from ISO/SEC 19075-6:

<JSON value expression> ::=
  <value expression> [ <JSON input clause> ]
<JSON input clause> ::=
  FORMAT <JSON representation>
<JSON representation> ::=
    JSON [ ENCODING { UTF8 | UTF16 | UTF32 } ]
  | <implementation-defined JSON representation option>

Currently it's an individual syntax standing out of Expression for easily implementing the behavior of "implicit JSON format". As the amount of JSON functions is getting larger, the design could definitely be improved. For example, it can be categorized as a PostfixOperator[1].

[1] https://github.com/apache/calcite/blob/master/core/src/main/java/org/apache/calcite/sql/SqlPostfixOperator.java

Issue Links

• is related to: CALCITE-2869 JSON data type support
• links to: GitHub Pull Request #1175