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https://issues.apache.org/jira/browse/CALCITE-7378?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
zzwqqq updated CALCITE-7378:
----------------------------
Description:
In dialects where `{{{}hasImplicitTableAlias{}}}is` true, even if a table is
explicitly assigned an alias in the original SQL, the `RelToSqlConverter` will
strip it away during the conversion. In scenarios like self-joins, if no
explicit alias is provided, column references will be incorrectly attributed to
the nearest table in the generated SQL structure.
This issue also occurs when handle TPC-H Query 21.
A minimal reproducible example：
{code:java}
select "product_name"
from "product" t1
where "product_id" not in (
select "product_id"
from "product" t2
where t2."product_id" = t1."product_id" and t1."product_id" = 2 and
t2."product_id" = 1){code}
after rel-to-sql
{code:java}
SELECT "product_name"
FROM "foodmart"."product"
WHERE "product_id" IN (
SELECT "product_id"
FROM "foodmart"."product"
WHERE "product_id" = "product"."product_id" AND "product"."product_id" = 2
AND "product_id" = 1){code}
{code:java}
"product_id" = "product"."product_id" AND "product"."product_id" = 2 AND
"product_id" = 1{code}
*In the new expression, all the "product_id" come from the nearest table, but
in the original SQL, it comes from t1 and t2 respectively.* And the new
expression always evaluates to false.
I suggest that when a correlated table alias shares the same name as the
current table identifier, the table alias should be required.
was:
In dialects where `{{{}hasImplicitTableAlias{}}}is` true, even if a table is
explicitly assigned an alias in the original SQL, the `RelToSqlConverter` will
strip it away during the conversion. In scenarios like self-joins, if no
explicit alias is provided, column references will be incorrectly attributed to
the nearest table in the generated SQL structure.
This issue also occurs when handle TPC-H Query 21.
A minimal reproducible example：
{code:java}
select "product_name"
from "product" t1
where "product_id" not in (select "product_id"
from "product" t2
where t2."product_id" = t1."product_id" and t1."product_id" = 2 and
t2."product_id" = 1){code}
after rel-to-sql
{code:java}
SELECT "product_name"
FROM "foodmart"."product"
WHERE "product_id" IN (SELECT "product_id"
FROM "foodmart"."product"
WHERE "product_id" = "product"."product_id" AND "product"."product_id" = 2 AND
"product_id" = 1){code}
{code:java}
"product"."product_id" = 2 AND "product_id" = 1{code}
The expression always evaluates to false.
I suggest that when a correlated table alias shares the same name as the
current table identifier, the table alias should be required.
> Potential incorrect column attribution in RelToSqlConverter due to implicit
> table alias handling
> ------------------------------------------------------------------------------------------------
>
> Key: CALCITE-7378
> URL: https://issues.apache.org/jira/browse/CALCITE-7378
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: zzwqqq
> Priority: Major
> Labels: pull-request-available
>
> In dialects where `{{{}hasImplicitTableAlias{}}}is` true, even if a table is
> explicitly assigned an alias in the original SQL, the `RelToSqlConverter`
> will strip it away during the conversion. In scenarios like self-joins, if no
> explicit alias is provided, column references will be incorrectly attributed
> to the nearest table in the generated SQL structure.
> This issue also occurs when handle TPC-H Query 21.
> A minimal reproducible example：
> {code:java}
> select "product_name"
> from "product" t1
> where "product_id" not in (
> select "product_id"
> from "product" t2
> where t2."product_id" = t1."product_id" and t1."product_id" = 2 and
> t2."product_id" = 1){code}
> after rel-to-sql
> {code:java}
> SELECT "product_name"
> FROM "foodmart"."product"
> WHERE "product_id" IN (
> SELECT "product_id"
> FROM "foodmart"."product"
> WHERE "product_id" = "product"."product_id" AND "product"."product_id" =
> 2 AND "product_id" = 1){code}
> {code:java}
> "product_id" = "product"."product_id" AND "product"."product_id" = 2 AND
> "product_id" = 1{code}
> *In the new expression, all the "product_id" come from the nearest table, but
> in the original SQL, it comes from t1 and t2 respectively.* And the new
> expression always evaluates to false.
> I suggest that when a correlated table alias shares the same name as the
> current table identifier, the table alias should be required.
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