You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@community.apache.org by "Gael Yimen Yimga (Jira)" <ji...@apache.org> on 2023/03/06 17:20:00 UTC
[jira] [Commented] (COMDEV-489) Apache ShardingSphere: Enhance SQLNodeConverterEngine to support more MySQL SQL statements
[ https://issues.apache.org/jira/browse/COMDEV-489?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17697050#comment-17697050 ]
Gael Yimen Yimga commented on COMDEV-489:
-----------------------------------------
Hello Mentors,
I started looking into this ticket and I have been investigating and debugging the *select_char* operator. Here is the beginning of my [thoughts|https://github.com/apache/shardingsphere/discussions/24097#discussioncomment-4996681]. I would like to give a proposal on how to solve the problem.
My findings are the following :
* I notice that for most of the MySQL functions, they are parsed as `*ExpressionSegment*`.
* That `*ExpressionSegment*` is converted into `*FunctionSegment*`.
* But the `*FunctionSegment*` that is supposed to have the parameters set does not have it.
The solution could be to find a mechanism to populate the parameters of `*FunctionSegment*` as a list of `*ExpressionSegment*`. By doing so the solution can fix al test case for the MySQL functions.
Please let me know what you think about.
> Apache ShardingSphere: Enhance SQLNodeConverterEngine to support more MySQL SQL statements
> ------------------------------------------------------------------------------------------
>
> Key: COMDEV-489
> URL: https://issues.apache.org/jira/browse/COMDEV-489
> Project: Community Development
> Issue Type: Improvement
> Components: GSoC/Mentoring ideas
> Reporter: Zhengqiang Duan
> Priority: Major
> Labels: Mentor, ShardingSphere, gsoc2023
>
> h2. Apache ShardingSphere
> Apache ShardingSphere is positioned as a Database Plus, and aims at building a standard layer and ecosystem above heterogeneous databases. It focuses on how to reuse existing databases and their respective upper layer, rather than creating a new database. The goal is to minimize or eliminate the challenges caused by underlying databases fragmentation.
> {*}Page{*}: [https://shardingsphere.apache.org|https://shardingsphere.apache.org/]
> {*}Github{*}: [https://github.com/apache/shardingsphere]
> h2. Background
> The ShardingSphere SQL federation engine provides support for complex SQL statements, and it can well support cross-database join queries, subqueries, aggregation queries and other statements. An important part of SQL federation engine is to convert the SQL statement parsed by ShardingSphere into SqlNode, so that Calcite can be used to implement SQL optimization and federated query.
> h2. Task
> This issue is to solve the MySQL exception that occurs during SQLNodeConverterEngine conversion. The specific case list is as follows.
> * select_char
> * select_extract
> * select_from_dual
> * select_from_with_table
> * select_group_by_with_having_and_window
> * select_not_between_with_single_table
> * select_not_in_with_single_table
> * select_substring
> * select_trim
> * select_weight_string
> * select_where_with_bit_expr_with_ampersand
> * select_where_with_bit_expr_with_caret
> * select_where_with_bit_expr_with_div
> * select_where_with_bit_expr_with_minus_interval
> * select_where_with_bit_expr_with_mod
> * select_where_with_bit_expr_with_mod_sign
> * select_where_with_bit_expr_with_plus_interval
> * select_where_with_bit_expr_with_signed_left_shift
> * select_where_with_bit_expr_with_signed_right_shift
> * select_where_with_bit_expr_with_vertical_bar
> * select_where_with_boolean_primary_with_comparison_subquery
> * select_where_with_boolean_primary_with_is
> * select_where_with_boolean_primary_with_is_not
> * select_where_with_boolean_primary_with_null_safe
> * select_where_with_expr_with_and_sign
> * select_where_with_expr_with_is
> * select_where_with_expr_with_is_not
> * select_where_with_expr_with_not
> * select_where_with_expr_with_not_sign
> * select_where_with_expr_with_or_sign
> * select_where_with_expr_with_xor
> * select_where_with_predicate_with_in_subquery
> * select_where_with_predicate_with_regexp
> * select_where_with_predicate_with_sounds_like
> * select_where_with_simple_expr_with_collate
> * select_where_with_simple_expr_with_match
> * select_where_with_simple_expr_with_not
> * select_where_with_simple_expr_with_odbc_escape_syntax
> * select_where_with_simple_expr_with_row
> * select_where_with_simple_expr_with_tilde
> * select_where_with_simple_expr_with_variable
> * select_window_function
> * select_with_assignment_operator
> * select_with_assignment_operator_and_keyword
> * select_with_case_expression
> * select_with_collate_with_marker
> * select_with_date_format_function
> * select_with_exists_sub_query_with_project
> * select_with_function_name
> * select_with_json_value_return_type
> * select_with_match_against
> * select_with_regexp
> * select_with_schema_name_in_column_projection
> * select_with_schema_name_in_shorthand_projection
> * select_with_spatial_function
> * select_with_trim_expr
> * select_with_trim_expr_from_expr
> You need to compare the difference between actual and expected, and then correct the logic in SQLNodeConverterEngine so that actual can be consistent with expected.
> After you make changes, remember to add case to SUPPORTED_SQL_CASE_IDS to ensure it can be tested.
>
> {*}Notice{*}, these issues can be a good example.
> [https://github.com/apache/shardingsphere/pull/14492|https://github.com/apache/shardingsphere/pull/15331]
> h2. Relevant Skills
>
> 1. Master JAVA language
> 2. Have a basic understanding of Antlr g4 file
> 3. Be familiar with MySQL and Calcite SqlNode
> h2. Targets files
>
> SQLNodeConverterEngineIT
> [https://github.com/apache/shardingsphere/blob/master/test/it/optimizer/src/test/java/org/apache/shardingsphere/test/it/optimize/SQLNodeConverterEngineIT.java]
> h3. Mentor
> Zhengqiang Duan, PMC of Apache ShardingSphere, duanzhengqiang@apache.org
> Chuxin Chen, Committer of Apache ShardingSphere, [tuichenchuxin@apache.org|mailto:tuichenchuxin@apache.org]
> Trista Pan, PMC of Apache ShardingSphere, panjuan@apache.org
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@community.apache.org
For additional commands, e-mail: dev-help@community.apache.org