Hequn Cheng created FLINK-11001:
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Summary: Window rowtime attribute can't be renamed in Java
Key: FLINK-11001
URL: https://issues.apache.org/jira/browse/FLINK-11001
Project: Flink
Issue Type: Bug
Environment:
Reporter: Hequn Cheng
Assignee: Hequn Cheng
Currently, we can rename window rowtime attribute like this in Scala:
{code:java}
table
.window(Tumble over 2.millis on 'rowtime as 'w)
.groupBy('w)
.select('w.rowtime as 'rowtime, 'int.count as 'int)
{code}
However, an exception will be thrown if we use java(by changing the Expressions
to String):
{code:java}
table
.window(Tumble over 2.millis on 'rowtime as 'w)
.groupBy('w)
.select("w.rowtime as rowtime, int.count as int")
{code}
The Exception is:
{code:java}
org.apache.flink.table.api.ExpressionParserException: Could not parse
expression at column 11: `,' expected but `a' found
w.rowtime as rowtime, int.count as int
{code}
To solve the problem, we can add rename support in {{ExpressionParser}}.
However, this may conflict with the design of source which use as before
rowtime:
{code:java}
stream.toTable(
tEnv,
ExpressionParser.parseExpressionList("(b as b).rowtime, c as c, a as a"):
_*)
{code}
Personally, I think we should keep the two consistent, so the final api would
be:
{code:java}
// window case
.select("w.rowtime as rowtime, int.count as int")
// source case
stream.toTable(
tEnv,
ExpressionParser.parseExpressionList("b.rowtime as b, c as c, a as a"):
_*)
{code}
Any suggestions would be greatly appreciated!
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