Feat(prql): add filter, set operations (#3291)

fool1280 · web-flow · commit eabb708db9ce · 2024-04-09T23:41:20.000+03:00
* filter for prql

* add todo

* add todo and test

* add append

* update set op

* update

* update CONJUCTION

* update FILTER
diff --git a/sqlglot/dialects/prql.py b/sqlglot/dialects/prql.py
@@ -7,7 +7,13 @@
 from sqlglot.tokens import TokenType
 
 
+def _select_all(table: exp.Expression) -> t.Optional[exp.Select]:
+    return exp.select("*").from_(table, copy=False) if table else None
+
+
 class PRQL(Dialect):
+    DPIPE_IS_STRING_CONCAT = False
+
     class Tokenizer(tokens.Tokenizer):
         IDENTIFIERS = ["`"]
         QUOTES = ["'", '"']
@@ -26,10 +32,26 @@ class Tokenizer(tokens.Tokenizer):
         }
 
     class Parser(parser.Parser):
+        CONJUNCTION = {
+            **parser.Parser.CONJUNCTION,
+            TokenType.DAMP: exp.And,
+            TokenType.DPIPE: exp.Or,
+        }
+
         TRANSFORM_PARSERS = {
             "DERIVE": lambda self, query: self._parse_selection(query),
             "SELECT": lambda self, query: self._parse_selection(query, append=False),
             "TAKE": lambda self, query: self._parse_take(query),
+            "FILTER": lambda self, query: query.where(self._parse_conjunction()),
+            "APPEND": lambda self, query: query.union(
+                _select_all(self._parse_table()), distinct=False, copy=False
+            ),
+            "REMOVE": lambda self, query: query.except_(
+                _select_all(self._parse_table()), distinct=False, copy=False
+            ),
+            "INTERSECT": lambda self, query: query.intersect(
+                _select_all(self._parse_table()), distinct=False, copy=False
+            ),
         }
 
         def _parse_statement(self) -> t.Optional[exp.Expression]:
diff --git a/tests/dialects/test_prql.py b/tests/dialects/test_prql.py
@@ -10,8 +10,35 @@ def test_prql(self):
         self.validate_identity("FROM x DERIVE x = a + 1", "SELECT *, a + 1 AS x FROM x")
         self.validate_identity("FROM x DERIVE {a + 1}", "SELECT *, a + 1 FROM x")
         self.validate_identity("FROM x DERIVE {x = a + 1, b}", "SELECT *, a + 1 AS x, b FROM x")
+        self.validate_identity(
+            "FROM x DERIVE {x = a + 1, b} SELECT {y = x, 2}", "SELECT a + 1 AS y, 2 FROM x"
+        )
         self.validate_identity("FROM x TAKE 10", "SELECT * FROM x LIMIT 10")
         self.validate_identity("FROM x TAKE 10 TAKE 5", "SELECT * FROM x LIMIT 5")
+        self.validate_identity("FROM x FILTER age > 25", "SELECT * FROM x WHERE age > 25")
         self.validate_identity(
-            "FROM x DERIVE {x = a + 1, b} SELECT {y = x, 2}", "SELECT a + 1 AS y, 2 FROM x"
+            "FROM x DERIVE {x = a + 1, b} FILTER age > 25",
+            "SELECT *, a + 1 AS x, b FROM x WHERE age > 25",
+        )
+        self.validate_identity("FROM x FILTER dept != 'IT'", "SELECT * FROM x WHERE dept <> 'IT'")
+        self.validate_identity(
+            "FROM x FILTER p == 'product' SELECT { a, b }", "SELECT a, b FROM x WHERE p = 'product'"
+        )
+        self.validate_identity(
+            "FROM x FILTER age > 25 FILTER age < 27", "SELECT * FROM x WHERE age > 25 AND age < 27"
+        )
+        self.validate_identity(
+            "FROM x FILTER (age > 25 && age < 27)", "SELECT * FROM x WHERE (age > 25 AND age < 27)"
+        )
+        self.validate_identity(
+            "FROM x FILTER (age > 25 || age < 27)", "SELECT * FROM x WHERE (age > 25 OR age < 27)"
+        )
+        self.validate_identity(
+            "FROM x FILTER (age > 25 || age < 22) FILTER age > 26 FILTER age < 27",
+            "SELECT * FROM x WHERE ((age > 25 OR age < 22) AND age > 26) AND age < 27",
+        )
+        self.validate_identity("FROM x APPEND y", "SELECT * FROM x UNION ALL SELECT * FROM y")
+        self.validate_identity("FROM x REMOVE y", "SELECT * FROM x EXCEPT ALL SELECT * FROM y")
+        self.validate_identity(
+            "FROM x INTERSECT y", "SELECT * FROM x INTERSECT ALL SELECT * FROM y"
         )
