Yash-cor commented on code in PR #34384:
URL: https://github.com/apache/shardingsphere/pull/34384#discussion_r1924987094
##########
infra/binder/src/main/java/org/apache/shardingsphere/infra/binder/engine/segment/dml/with/WithSegmentBinder.java:
##########
@@ -71,18 +74,26 @@ public static WithSegment bind(final WithSegment segment,
final SQLStatementBind
}
private static SimpleTableSegmentBinderContext
createWithTableBinderContext(final CommonTableExpressionSegment
commonTableExpressionSegment) {
- return new
SimpleTableSegmentBinderContext(commonTableExpressionSegment.getSubquery().getSelect().getProjections().getProjections());
+ if (commonTableExpressionSegment.getColumns().isEmpty()) {
+ return new
SimpleTableSegmentBinderContext(commonTableExpressionSegment.getSubquery().getSelect().getProjections().getProjections());
+ } else {
+ Collection<ProjectionSegment> projectionSegments = new
LinkedList<>();
+ commonTableExpressionSegment.getColumns().forEach(each ->
projectionSegments.add(new ColumnProjectionSegment(each)));
Review Comment:
Hello @strongduanmu while changing the logic I found Error in the way
WithSegment is handling Recursive segment of with clause.
- Recursive segment allows user to use the same common table expression (
cte ) name in cte's subquery
Example -
```
WITH RECURSIVE cte AS
(
SELECT 1 as (n)
UNION ALL
SELECT n + 1 FROM cte WHERE n < 5
)
SELECT * FROM cte;
```
or similarly can be written as
```
WITH RECURSIVE cte (n) AS
(
SELECT 1
UNION ALL
SELECT n + 1 FROM cte WHERE n < 5
)
SELECT * FROM cte;
```
- The WITH clause must begin with WITH RECURSIVE if any CTE in the WITH
clause refers to itself. (If no CTE refers to itself, RECURSIVE is permitted
but not required.) We have to include a check for it.
- The recursive CTE subquery has two parts, separated by UNION ALL or UNION
DISTINCT. Thus, a recursive CTE consists of a non-recursive SELECT part
followed by a recursive SELECT part. Should i include a check for it as this
check happens when the query hits the MySQL database.
##########
infra/binder/src/main/java/org/apache/shardingsphere/infra/binder/engine/segment/dml/with/WithSegmentBinder.java:
##########
@@ -71,18 +74,26 @@ public static WithSegment bind(final WithSegment segment,
final SQLStatementBind
}
private static SimpleTableSegmentBinderContext
createWithTableBinderContext(final CommonTableExpressionSegment
commonTableExpressionSegment) {
- return new
SimpleTableSegmentBinderContext(commonTableExpressionSegment.getSubquery().getSelect().getProjections().getProjections());
+ if (commonTableExpressionSegment.getColumns().isEmpty()) {
+ return new
SimpleTableSegmentBinderContext(commonTableExpressionSegment.getSubquery().getSelect().getProjections().getProjections());
+ } else {
+ Collection<ProjectionSegment> projectionSegments = new
LinkedList<>();
+ commonTableExpressionSegment.getColumns().forEach(each ->
projectionSegments.add(new ColumnProjectionSegment(each)));
Review Comment:
> Can you move this logic to CommonTableExpressionSegmentBinder?
Along with this should we also move the bindWithColumns to
CommonTableExpressionBinder.
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