Allowing cascading joins

This commit is contained in:
simon petit 2024-11-25 10:36:33 +00:00
parent 9326be1ba9
commit e5b15bf93f
3 changed files with 96 additions and 39 deletions

View File

@ -6,7 +6,7 @@ and column =
| Column of string | Column of string
and table = and table =
| Table of string | Table of string
| Join of table * join_type * table | Join of table * join_type * table * condition option
and join_type = and join_type =
| Inner | Inner
| Left | Left
@ -15,4 +15,19 @@ and join_type =
| Cross | Cross
| Union | Union
| Natural | Natural
and condition =
| Condition of string * comparison
| And of condition * condition
| Or of condition * condition
| Not of condition
and comparison =
| Comparison of operator * string
and operator =
| Equals
| NotEquals
| LessThan
| GreaterThan
| LessEquals
| GreaterEquals
and search_condition =
| Search of string

View File

@ -53,7 +53,6 @@ table_reference :
(* | table_primary_or_joined_table sample_clause { $1 } *) (* | table_primary_or_joined_table sample_clause { $1 } *)
table_primary_or_joined_table: table_primary_or_joined_table:
(* | table_primary { Table($1) }*)
| table_primary { $1 } | table_primary { $1 }
| joined_table { $1 } | joined_table { $1 }
@ -70,24 +69,24 @@ joined_table :
| union_join { $1 } | union_join { $1 }
cross_join: cross_join:
| table_reference CROSS JOIN table_primary { Join($1, Cross, $4) } | table_reference CROSS JOIN table_primary { Join($1, Cross, $4, None) }
qualified_join: qualified_join:
| table_reference JOIN table_reference join_specification { Join($1, Left, $3) } | table_reference JOIN table_reference join_specification { Join($1, Left, $3, $4) }
| table_reference join_type JOIN table_reference join_specification { Join($1, $2, $4) } | table_reference join_type JOIN table_reference join_specification { Join($1, $2, $4, $5) }
join_specification: join_specification:
| join_condition {} | join_condition { $1 }
join_condition: join_condition:
| ON search_condition {} | ON search_condition { Some($2) }
natural_join: natural_join:
| table_reference NATURAL JOIN table_primary { Join($1, Natural, $4) } | table_reference NATURAL JOIN table_primary { Join($1, Natural, $4, None) }
| table_reference NATURAL join_type JOIN table_primary { Join($1, Natural, $5) } | table_reference NATURAL join_type JOIN table_primary { Join($1, Natural, $5, None) }
union_join: union_join:
| table_reference UNION JOIN table_primary { Join($1,Union, $4) } | table_reference UNION JOIN table_primary { Join($1, Union, $4, None) }
table_name : table_name :
| IDENT { Table($1) } | IDENT { Table($1) }
@ -107,43 +106,44 @@ where_clause :
| WHERE search_condition { } | WHERE search_condition { }
search_condition: search_condition:
| IDENT EQUALS_OPERATOR IDENT {} (*| IDENT EQUALS_OPERATOR IDENT {}*)
| boolean_value_expression { $1 }
boolean_value_expression: boolean_value_expression:
| boolean_term {} | boolean_term { $1 }
| boolean_value_expression OR boolean_term {} | boolean_value_expression OR boolean_term { Or($1, $3) }
boolean_term: boolean_term:
| boolean_factor {} | boolean_factor { $1 }
| boolean_term AND boolean_factor {} | boolean_term AND boolean_factor { And($1, $3) }
boolean_factor: boolean_factor:
| boolean_test {} | boolean_test { $1 }
| NOT boolean_test {} | NOT boolean_test { Not($2) }
boolean_test: boolean_test:
| boolean_primary {} | boolean_primary { $1 }
boolean_primary : boolean_primary :
| predicate {} | predicate { $1 }
| boolean_predicand {} (*| boolean_predicand {}*)
predicate : predicate :
| comparison_predicate {} | comparison_predicate { $1 }
comparison_predicate : comparison_predicate :
| row_value_predicand comparison_predicate_part2 {} | row_value_predicand comparison_predicate_part2 { Condition($1, $2) }
comparison_predicate_part2: comparison_predicate_part2:
| comp_op row_value_predicand {} | comp_op row_value_predicand { Comparison($1, $2) }
comp_op : comp_op :
| EQUALS_OPERATOR {} | EQUALS_OPERATOR { Equals }
| not_equals_operator {} | not_equals_operator { NotEquals }
| LESS_THAN_OPERATOR {} | LESS_THAN_OPERATOR { LessThan }
| GREATER_THAN_OPERATOR {} | GREATER_THAN_OPERATOR { GreaterThan }
| less_than_or_equals_operator {} | less_than_or_equals_operator { LessEquals }
| greater_than_or_equals_operator {} | greater_than_or_equals_operator { GreaterEquals }
not_equals_operator : not_equals_operator :
| LESS_THAN_OPERATOR GREATER_THAN_OPERATOR {} | LESS_THAN_OPERATOR GREATER_THAN_OPERATOR {}
@ -155,23 +155,23 @@ greater_than_or_equals_operator:
| GREATER_THAN_OPERATOR EQUALS_OPERATOR {} | GREATER_THAN_OPERATOR EQUALS_OPERATOR {}
row_value_predicand: row_value_predicand:
| row_value_special_case {} | row_value_special_case { $1 }
row_value_special_case : row_value_special_case :
| nonparenthesized_value_expression_primary {} | nonparenthesized_value_expression_primary { $1 }
nonparenthesized_value_expression_primary: nonparenthesized_value_expression_primary:
| column_reference {} | column_reference { $1 }
column_reference: column_reference:
| basic_identifier_chain {} | basic_identifier_chain { $1 }
basic_identifier_chain: basic_identifier_chain:
| identifier_chain {} | identifier_chain { $1 }
identifier_chain: identifier_chain:
| IDENT {} | IDENT { $1 }
| identifier_chain DOT IDENT {} (*| identifier_chain DOT IDENT {}*)
boolean_predicand: boolean_predicand:
| nonparenthesized_value_expression_primary {} | nonparenthesized_value_expression_primary {}

View File

@ -7,5 +7,47 @@ let parse query =
let () = let () =
assert(parse "SELECT ab FROM b1" = Query(Select([Column("ab")], [Table "b1"]))); assert(parse "SELECT ab FROM b1" = Query(Select([Column("ab")], [Table "b1"])));
assert(parse "SELECT * FROM b1" = Query(Select([Asterisk], [Table "b1"]))); assert(parse "SELECT * FROM b1" = Query(Select([Asterisk], [Table "b1"])));
assert(parse "SELECT * FROM t1 CROSS JOIN t2" = Query(Select([Asterisk], [Join(Table("t1"), Cross, Table("t2"))]))); assert(parse "SELECT * FROM t1 CROSS JOIN t2" = Query(Select([Asterisk], [Join(Table("t1"), Cross, Table("t2"), None)])));
assert(parse "SELECT * FROM t1 JOIN t2 ON a = b" = Query(Select([Asterisk], [Join(Table("t1"), Left, Table("t2"))]))); assert(parse "SELECT * FROM t1 JOIN t2 ON a = b" = Query(
Select([Asterisk], [
Join(
Table("t1"),
Left,
Table("t2"),
Some(
Condition(
"a",
Comparison(Equals, "b")
)
)
)
]
)
));
assert(parse "SELECT * FROM t1 JOIN t2 ON a = b JOIN t3 ON c = d" = Query(
Select([Asterisk], [
Join(
Join(
Table("t1"),
Left,
Table("t2"),
Some(
Condition(
"a",
Comparison(Equals, "b")
)
)
),
Left,
Table("t3"),
Some(
Condition(
"c",
Comparison(Equals, "d")
)
)
)
]
)
)
);