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Title: Refactor Parenthesed SelectBody and FromItem by manticore-projects · Pull Request #1754 · JSQLParser/JSqlParser · GitHub

Open Graph Title: Refactor Parenthesed SelectBody and FromItem by manticore-projects · Pull Request #1754 · JSQLParser/JSqlParser

X Title: Refactor Parenthesed SelectBody and FromItem by manticore-projects · Pull Request #1754 · JSQLParser/JSqlParser

Description: This is a heavy API breaking refactoring on the bracket-handling related to SelectBody, FromItem and OperationSet, SubSelect, WithItem: it fixes some issues and wrong examples (e. g. Test for #1094, which was incorrect) simplifies the Grammar and drops some redundant productions (e. g. SubSelect, SpecialSubSelect, SubJoin, SubJoinList, SetOperationListWithoutIntialSelect, ValuesList) It should warrant a major Version JSQLParser-5.0 and also people should properly test it before. Goal: get rid of all the "hasBrackets" properties for any entity move JoinList from PlainSelect to FromItem (since there can't be a Join without a From) SelectBody replaces SubSelect and implements FromItem directly This has the big advantaged, that any occurrence of ( table=Table() | subSelect=SubSelect() ) can be parsed as fromItem=FromItem() without LOOKAHEAD (for example Merge parses a simple FromItem now) SelectBody implements Statement directly and so becomes the Select Statement (removing 1 hierarchy level from the AST): -- before statement = new Select().withSelectBody(new PlainSelect() .addSelectItems(new AllTableColumns().withTable(t)).withFromItem(t)); statement = new Select().withSelectBody(new ValuesStatement().withExpressions(expressionList)); -- now better ( when SelectBody became Select, all its implementations became a Statement ) statement = new PlainSelect() .addSelectItems(new AllTableColumns().withTable(t)).withFromItem(t); statement = new Values().withExpressions(expressionList); LateralSubSelect extends ParenthesedSelectBody (axing SubSelect and SpecialSubSelect ) values.ValuesStatement becomes select.Values implementing SelectBody (with Statement and FromItem). So we got rid of ValuesList move ORDER BY, LIMIT, OFFSET, FETCH, WITH isolation into SelectBody since all its implementations support it -- valid SQL values(1,2,3) limit 1 -- valid SQL (values(1,2,3)) limit 1 Nested WithItems with a as ( with b as ( with c as (select 1) select c.* from c ) select b.* from b ) select a.* from a Merge implements the Visitor Pattern all the Tests succeed verify/validate performance. It is a little bit slower but much more correct. Before: 42500 statements parsed in 13095 milliseconds (3245 statements per second, 0.0003082 seconds per statement ) 38500 select scans for table name executed in 80 milliseconds (481250 select scans for table name per second, 0.0000021 seconds per select scans for table name) New: 42500 statements parsed in 15062 milliseconds (2821 statements per second, 0.0003545 seconds per statement ) 38500 select scans for table name executed in 101 milliseconds (381188 select scans for table name per second, 0.0000026 seconds per select scans for table name) so far 900 lines less code at better functionality and simplicity (traversing the AST got much easier) Fixes #1737 Fixes #1764 Succeeds on another Special Oracle Test Condition15 Succeeds on another Special Oracle Test Cast_MultiSet07 @wumpz Please start reviewing and provide feedback as early as possible.

Open Graph Description: This is a heavy API breaking refactoring on the bracket-handling related to SelectBody, FromItem and OperationSet, SubSelect, WithItem: it fixes some issues and wrong examples (e. g. Test for #109...

X Description: This is a heavy API breaking refactoring on the bracket-handling related to SelectBody, FromItem and OperationSet, SubSelect, WithItem: it fixes some issues and wrong examples (e. g. Test for #109...

Opengraph URL: https://github.com/JSQLParser/JSqlParser/pull/1754

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