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https://issues.apache.org/jira/browse/CALCITE-7508?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18096010#comment-18096010
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Haris Sattar commented on CALCITE-7508:
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Hi [~krooswu] ,
Apologies for the missing context — this issue only manifests when using a
dialect where hasImplicitTableAlias() returns true (e.g., PrestoSqlDialect).
With the default dialect, alias uniquification works correctly and the mismatch
doesn't occur.
To reproduce, use a correlated scalar subquery in the SELECT list with
PrestoSqlDialect:
RelToSqlConverter converter = new RelToSqlConverter(PrestoSqlDialect.DEFAULT);
With a query like:
SELECT id, (SELECT SUM(value) FROM table_b WHERE table_b.id = table_a.id) AS
total FROM table_a
The correlation reference will emit an alias (e.g., "t0"."id") that doesn't
match the outer table's FROM clause (AS "t").
> RelToSqlConverter registers wrong alias for correlation variable in
> visit(Project)
> ----------------------------------------------------------------------------------
>
> Key: CALCITE-7508
> URL: https://issues.apache.org/jira/browse/CALCITE-7508
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.39.0
> Reporter: Haris Sattar
> Assignee: krooswu
> Priority: Major
> Labels: pull-request-available
>
> *Example:*
> Input RelNode tree: a correlated scalar subquery where the outer table is
> table_a and the inner table is table_b, correlated on column "id".
> *Expected SQL output:*
> SELECT "id",
> (SELECT SUM("value") FROM "table_b" AS "t1"
> WHERE "id" = "t"."id") AS "total_value"
> FROM "table_a" AS "t"
> *Actual SQL output:*
> SELECT "id",
> (SELECT SUM("value") FROM "table_b" AS "t1"
> WHERE "id" = "t0"."id") AS "total_value"
> FROM "table_a" AS "t"
> The correlation reference emits "t0"."id" but the outer table's FROM clause
> says AS "t". "t0" does not exist in the query. The SQL is invalid and will be
> rejected by the execution engine.
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