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Query: Add TableReferenceExpression as a bridge to ColumnExpression for referential integrity #24458

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merged 1 commit into from
Mar 23, 2021

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smitpatel
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@smitpatel smitpatel commented Mar 19, 2021

Part of #17337

  • Add TableReferenceExpression
  • SelectExpression contains tableReferenceExpression for each table added
  • TableReferenceExpression can identify the table by querying the selectExpression
  • During pushdown and set operation we update the table references as the selectExpression where columns belong is changing
  • Whenever adding something to selectExpression, we assign unique alises if there is nested selectExpression
  • Improve identifier detection for Distinct/GroupBy cases
  • Pushdown internally gives a visitor to update the expression being added in terms of new column expressions
  • Copy proper identifiers when applying set operation
  • Make dictionary being passed around in query IReadOnlyDictionary
  • Move entityProjectionCache from QueryExpression to ProjectionBindingExpressionVisitor as it is not an internal state for QueryExpression. It existing only in the context of applying particular projection mapping once.
  • Remove TableAliasUniquifyingExpressionVisitor, added debug only (currently disabled) TableAliasVerifyingExpressionVisitor which verifies that all alises are unique and used in order.

@smitpatel smitpatel marked this pull request as draft March 19, 2021 23:11
@smitpatel smitpatel force-pushed the smit/ABriefRevisitToGraphTheory branch from 48b9bc3 to f801da6 Compare March 20, 2021 07:42
@smitpatel smitpatel changed the title Query: Add TableReferenceExpression as a bridge to ColumnExpression f… Query: Add TableReferenceExpression as a bridge to ColumnExpression for referential integrity Mar 20, 2021
@smitpatel smitpatel force-pushed the smit/ABriefRevisitToGraphTheory branch from f801da6 to 1d2cd44 Compare March 20, 2021 07:58
@smitpatel smitpatel force-pushed the smit/ABriefRevisitToGraphTheory branch 3 times, most recently from 7ba85c7 to fb3c5b8 Compare March 22, 2021 20:53
@smitpatel smitpatel marked this pull request as ready for review March 23, 2021 00:22
<data name="UnableToTranslateSubqueryWithDistinct" xml:space="preserve">
<value>Subquery with 'Distinct' can only be translated if projection consists only of entities and their properties, or it contains keys of all entities required to generate results on the client side. Either add '{column}' to the projection, remove complex elements of the projection, or rewrite the query to not use the 'Distinct' operation.</value>
</data>
<data name="UnableToTranslateSubqueryWithGroupBy" xml:space="preserve">
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since these are gone, we should probably also update message for InsufficientInformationToIdentifyOuterElementOfCollectionJoin

@smitpatel smitpatel force-pushed the smit/ABriefRevisitToGraphTheory branch from dd7277f to 6e46d5f Compare March 23, 2021 16:06
Base automatically changed from smit/movingaround to main March 23, 2021 16:54
…or referential integrity

- Add TableReferenceExpression
- SelectExpression contains tableReferenceExpression for each table added
- TableReferenceExpression can identify the table by querying the selectExpression
- During pushdown and set operation we update the table references as the selectExpression where columns belong is changing
- Whenever adding something to selectExpression, we assign unique alises if there is nested selectExpression
- Improve identifier detection for Distinct/GroupBy cases
- Pushdown internally gives a visitor to update the expression being added in terms of new column expressions
- Copy proper identifiers when applying set operation
- Make dictionary being passed around in query IReadOnlyDictionary
- Move entityProjectionCache from QueryExpression to ProjectionBindingExpressionVisitor as it is not an internal state for QueryExpression. It existing only in the context of applying particular projection mapping once.
- Remove TableAliasUniquifyingExpressionVisitor, added debug only (currently disabled) TableAliasVerifyingExpressionVisitor which verifies that all alises are unique and used in order.

Resolves #17337
@smitpatel smitpatel force-pushed the smit/ABriefRevisitToGraphTheory branch from 6e46d5f to 247ce69 Compare March 23, 2021 16:56
@smitpatel smitpatel merged commit 26c0d2a into main Mar 23, 2021
@smitpatel smitpatel deleted the smit/ABriefRevisitToGraphTheory branch March 23, 2021 17:36
@sfsharapov
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Why not to make TableReferenceExpression and ColumnExpression classes public? After these changes EfCore.SqlServer2008Query package could not translate queries as it was worked in fifth version.

@smitpatel
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ColumnExpression is still a public class.
As for TableReferenceExpression it is not public it is a transparent wrapper which no one is supposed to access or use other than SelectExpression internally as an implementation detail. If something stops working after this change then that code is probably written incorrectly using wrong set of APIs and worked by chance.

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sfsharapov commented Nov 16, 2021

ColumnExpression is still a public class.

Sorry, I meant ConcreteColumnExpression. ColumnExpression, used before introducing ConcreteColumnExpression, is public.

@smitpatel
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Notes same as TableReferenceExpression applies to ConcreteColumnExpression too. It is implementation details and no one needs to know about it.

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3 participants