[ASTERIXDB-2401] Support parameterized queries

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Component/s: SQL - Translator SQL++
• Assignee: Dmitry Lychagin
• Reporter: Dmitry Lychagin
• Created: 13/Jun/18 00:33
• Updated: 15/Jun/18 17:01
• Resolved: 15/Jun/18 17:01

Description

We need to support external statement parameters in SQL++. They can be of three kinds:
1) Named parameters, referred as: $name

2) Positional parameters, referred as: $n where n is an integer, >= 1

3) Positional parameters, referred as ?, which are treated as $1, ... $n in the order in which they appear in the statement.

Parameters should be assignable through the statement execution API (/query/service). 

For each named parameter there should be a request parameter "$name" which contains the parameter's JSON value.

Positional parameters are passed in "args" request parameter which should be a JSON array containing parameter values.

Statement parameters should be inlined at query compilation time, so they do not impact query optimization.

It's an error if a statement parameter is referred by a query but its value is not provided in the API request.