feat: default value for source/(table with conn)

[st1page]

Currently, the definition on the source/table with conn will not take effect

create table t (
  x int,
  y int default 1,
  z timestamptz default now(),
) with (
  connector = 'kafka',
  topic = 't',
  properties.bootstrap.server = 'localhost:29092',
  scan.startup.mode = 'earliest'
) FORMAT PLAIN ENCODE JSON;

when insert {"x":"1"} to the topic, it will be resolved as

dev=> select * from mv;
 x | y | z 
---+---+---
 1 |   | 
(1 row)

using create source will get the same result.

[BugenZhao]

If we're going to support it, we should also update this to pad the specified default values for parsing failures.

risingwave/src/connector/src/parser/mod.rs

Line 359 in 14b2f9c

// TODO: figure out a way to fill in not-null default value if user specifies one

[xiangjinwu]

To clarify, does it only apply to json / csv where columns are listed in SQL?

For protobuf and avro, columns are derived and each encoding has their own specification about default values: protobuf avro

[st1page]

To clarify, does it only apply to json / csv where columns are listed in SQL?

For protobuf and avro, columns are derived and each encoding has their own specification about default values: protobuf avro

Good point. I think for protobuf or avro, we need to give user an error to tell them the default value declared in the create statement does not take effect.