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Use statement #936

Merged
merged 5 commits into from
Aug 18, 2023
Merged

Use statement #936

merged 5 commits into from
Aug 18, 2023

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jiashenC
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Working example

USE postgres {
    CREATE TABLE (...)
}

@jiashenC jiashenC requested review from gaurav274 and xzdandy August 17, 2023 18:13
@jiashenC
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@xzdandy @gaurav274 You can give read about the design. I will add more implementations to check in binder/catalog.

@xzdandy
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xzdandy commented Aug 17, 2023

For use query, we have the option to skip the binder and optimizer using SKIP_BINDER_AND_OPTIMIZER_STATEMENTS. This can simplify the implementation.

@jiashenC
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For use query, we have the option to skip the binder and optimizer using SKIP_BINDER_AND_OPTIMIZER_STATEMENTS. This can simplify the implementation.

I meant just checking if the data source is valid. Not gonna check anything for the native query.

@@ -172,11 +174,19 @@ explain_statement: EXPLAIN explainable_statement

explainable_statement : select_statement | insert_statement | update_statement | delete_statement | create_table

// Context Statements

use_statement: USE database_name "{" query_string "}" // One shortcoming that query string cannot have parenthesis
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Is this the limitation of the lark or ? Why we can not have parenthesis?

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I will remove this comment. The native query can have parenthesis after I change to use curly bracket if that makes sense

// now
USE postgres {
   // some query
}

// before
USE postgres (
    // some query
)

If I use the parenthesis and the native query has arbitrary parentheses as well, I have some trouble of coming up with a grammar that works for all cases.

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Let me take care of it

@@ -1239,3 +1240,37 @@ def __hash__(self) -> int:
self.search_query_expr,
)
)


class LogicalUse(Operator):
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Can you also bypass optimizer for use? Just to simplify the code

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Will push the code to take care of this

engine = create_engine(conn_str)

with engine.connect() as con:
if "SELECT" in self._query_string or "select" in self._query_string:
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We need to make this robust for cases where select is used for creating tables etc. Also, if query contains Select etc

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What is the output for CREATE TABLE from sqlalchemy? Is it possible to simply execute the query and yield whatever output sqlalchemy yields in dataframe type?

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I like this idea

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sqlalchemy/sqlalchemy#5433 (comment)

Based on what I see, it is still true for this API for latest SQLAlchemy. There is no rows returned besides SELECT.

@gaurav274 gaurav274 merged commit 045db67 into master Aug 18, 2023
@gaurav274 gaurav274 deleted the use-statement branch August 18, 2023 15:25
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3 participants