Re:How to dynamically modify the schema information of a table

[Xuyang]

I tried this and found that the comment information will be lost forever when 
using "fromDataStream". I think you can create a issue to report this bug.



At 2022-04-22 10:44:47, "草莓" <w757227...@163.com> wrote:

The following is the Java code


@Test
public void test(){
StreamExecutionEnvironment env = 
StreamExecutionEnvironment.getExecutionEnvironment();
StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);
DataStream<String> dataStream = env.fromElements("Alice", "Bob", "John");
Schema.Builder builder = Schema.newBuilder();
builder.column("f0",DataTypes.of(String.class)).withComment("this is a 
comment");
Table table = tableEnv.fromDataStream(dataStream, 
builder.build()).as("user_name");
table.getResolvedSchema();
table.printSchema();
}


Its output is:
(
  `user_name` STRING
)


My question is, if the comment is lost, what should I do to display the comment 
information?


What I need is that the result is
(
  `user_name` STRING COMMENT 'this is a comment'
)