Support UNION
#78
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jaypipes
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May 21, 2018
UNION JOIN is a rare join type that was supported in ANSI-92 SQL but subsequently removed from the SQL standard in ANSI SQL:2003. Issue #78
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jaypipes
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May 26, 2018
In supporting UNION/INTERSECT/EXCEPT, we need to segregate the parsing of query expression components from both table references and the select_statement_t. This patch adds specific parsers for the following query expression components: - <non_join_query_expression> - <non_join_query_term> - <non_join_query_primary> - <query_term> - <query_primary> - <joined_table> - <query_expression> The parsing of <query_specification> (which is basically the SELECT statement) is left for a followup patch, since that will need to reshape the parse_select() function substantially. Issue #78 Issue #111 Issue #112
jaypipes
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May 26, 2018
The remaining pieces of the separate query component parsers were the parsing of the query_specification_t and table_expression_t. Next step is to convert parse_select() into a smaller parser that calles parse_query_specification() and checks terminal symbols that can come after a SELECT statement. Issue #78 Issue #111 Issue #112
jaypipes
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May 29, 2018
query expressions, query terms and query primaries are all query components. They can either contains non-join elements or joined table elements. So, instead of having a query_expression_type, query_term_type and query_primary_type, let's just have a single query_component_type that can be used by all of the query component subclasses. Issue #78
jaypipes
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May 29, 2018
Makes non_join_query_term_t a derivative of query_term_t and prepares the term parser for upcoming INTERSECTS processing. Issue #78
jaypipes
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May 29, 2018
Makes non_join_query_primary_t derive properly from query_primary_t and make sure that parse_query_primary() properly attempts to parse a non_join_query_primary_t first, then a joined_table_t if that failed. Issue #78
jaypipes
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Jun 13, 2018
query expressions, query terms and query primaries are all query components. They can either contains non-join elements or joined table elements. So, instead of having a query_expression_type, query_term_type and query_primary_type, let's just have a single query_component_type that can be used by all of the query component subclasses. Issue #78
jaypipes
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Jun 13, 2018
Makes non_join_query_term_t a derivative of query_term_t and prepares the term parser for upcoming INTERSECTS processing. Issue #78
jaypipes
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Jun 13, 2018
Makes non_join_query_primary_t derive properly from query_primary_t and make sure that parse_query_primary() properly attempts to parse a non_join_query_primary_t first, then a joined_table_t if that failed. Issue #78
jaypipes
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Jun 14, 2018
Most of the patch is test file updates after doing the necessary breakout of the YAML printers for query_term_t and the various query_expression_t subtypes. We begin the process of parsing UNION and EXCEPT query expressions but as of now do not include functional tests for those expression subtypes. That will come in a following patch, since this is already getting a little long in the tooth. Issue #78
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Need to support the
UNIONoperation which combines the results of two selectionsThe text was updated successfully, but these errors were encountered: