[jira] [Commented] (FLINK-27275) Support partial insert in flink-connector-jdbc

["Martijn Visser (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-27275?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17524128#comment-17524128 ] 

Martijn Visser commented on FLINK-27275:
----------------------------------------

[~liufangliang] How do you see this work for users where the current behavior is actually the desired behavior? We've had similar discussions for other connectors and decided not to change it, because there are users groups who explicitly want to overwrite values with null and there's user groups who don't. 

> Support partial insert in flink-connector-jdbc
> ----------------------------------------------
>
>                 Key: FLINK-27275
>                 URL: https://issues.apache.org/jira/browse/FLINK-27275
>             Project: Flink
>          Issue Type: New Feature
>          Components: Connectors / JDBC
>    Affects Versions: 1.14.3
>            Reporter: Fangliang Liu
>            Priority: Major
>
> I use the following statement to create a flink job.
> a field in the source data is null, but the field in mysql is not null, then the field will be overwritten by null after the record is written to the database. If I don't want this historical value to be overwritten by null, it is necessary to take out the historical value in the database in this task, and then update it to the database again, which is very costly for us.
> So, i think the choice of whether to update to the database if a field is null can actually be left to the use.
> {code:java}
>  CREATE TABLE IF NOT EXISTS t_source (
>     `user_id`  bigint,
>     `A` string,
>     `B` string,
>     `C` string,
>     `flag` varchar(256)
> )WITH (
>     'connector' = 'kafka',
>     'format' = 'canal-json',
>     'scan.startup.mode' = 'latest-offset',
>     ... ...
> );
> CREATE TABLE IF NOT EXISTS t_sink (
>     `user_id`  bigint,
>     `A` string,
>     `B` string,
>     `C` string,
>     `flag` varchar(256),
>     PRIMARY KEY (`user_id`) NOT ENFORCED
> )WITH (
>     'connector' = 'jdbc',
>     'url' = 'jdbc:mysql://xx.xx.xx.xx:xxx/test',
>     'table-name' = 'user',
>     ... ...
>  ); 
> INSERT INTO t_sink(
>     `user_id`,
>     `A`,
>     `B`,
>     `C`,
>     `flag`
> ) SELECT  `user_id`, `A`, `B`, `C`, `flag` FROM t_source;
> {code}
>  



--
This message was sent by Atlassian Jira
(v8.20.1#820001)