Case conditions

CHANGELOG.md

@@ -1,8 +1,12 @@
 # Changelog
 
+## 0.10.0 : 2021-11-30
+
+- **Feature**: `Case` introduced (without docs, there was no time, sry, let's call it Easter Egg for a while)
+
 ## 0.9.1 : 2021-07-20
 
-- **Fix**: Fixed problem with multiple properites in operations (I had to remove comparison property check)
+- **Fix**: Fixed problem with multiple properties in operations (I had to remove comparison property check)
 
 ## 0.9.0 : 2021-06-25
 

duckql/functions/avg.py

@@ -9,11 +9,12 @@
 from ..properties import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Avg(BaseFunction):
     obj: Literal['functions.Avg'] = 'functions.Avg'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/concat.py

@@ -9,11 +9,12 @@
 from ..properties.property import Property
 from ..properties.constant import Constant
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Concat(BaseFunction):
     obj: Literal['functions.Concat'] = 'functions.Concat'
-    properties: List[Union[Property, BaseFunction, Constant, CastOperator]]
+    properties: List[Union[Property, BaseFunction, Constant, CastOperator, Case]]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/convert_timezone.py

@@ -9,11 +9,12 @@
 from ..properties.constant import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class ConvertTimezone(BaseFunction):
     obj: Literal['functions.ConvertTimezone'] = 'functions.ConvertTimezone'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     date_from: Constant
     date_to: Constant
     alias: str = None

duckql/functions/count.py

@@ -10,11 +10,12 @@
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
 from ..structures.distinct import Distinct
+from ..structures.case import Case
 
 
 class Count(BaseFunction):
     obj: Literal['functions.Count'] = 'functions.Count'
-    property: Union[Property, BaseFunction, Constant, CastOperator, Distinct]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Distinct, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/date_add.py

@@ -10,11 +10,12 @@
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
 from ..structures.interval import Interval
+from ..structures.case import Case
 
 
 class DateAdd(BaseFunction):
     obj: Literal['functions.DateAdd'] = 'functions.DateAdd'
-    property: Union[Constant, Property, BaseFunction, CastOperator]
+    property: Union[Constant, Property, BaseFunction, CastOperator, Case]
     interval: Interval
     alias: str = None
 

duckql/functions/date_format.py

@@ -11,11 +11,12 @@
 from ..properties.property import Property
 from ..properties.constant import Constant
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class DateFormat(BaseFunction):
     obj: Literal['functions.DateFormat'] = 'functions.DateFormat'
-    property: Union[Property, Constant, BaseFunction, CastOperator]
+    property: Union[Property, Constant, BaseFunction, CastOperator, Case]
     format: str
     alias: str = None
 

duckql/functions/date_sub.py

@@ -10,11 +10,12 @@
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
 from ..structures.interval import Interval
+from ..structures.case import Case
 
 
 class DateSub(BaseFunction):
     obj: Literal['functions.DateSub'] = 'functions.DateSub'
-    property: Union[Constant, Property, BaseFunction, CastOperator]
+    property: Union[Constant, Property, BaseFunction, CastOperator, Case]
     interval: Interval
     alias: str = None
 

duckql/functions/extract.py

@@ -11,6 +11,7 @@
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
 from ..structures.interval import Interval
+from ..structures.case import Case
 
 
 class Extract(BaseFunction):
@@ -38,7 +39,7 @@ class Unit(Enum):
         YEAR = 'year'
 
     obj: Literal['functions.Extract'] = 'functions.Extract'
-    property: Union[Constant, Property, BaseFunction, Interval, CastOperator]
+    property: Union[Constant, Property, BaseFunction, Interval, CastOperator, Case]
     unit: Unit
     alias: str = None
 

duckql/functions/group_concat.py

@@ -9,11 +9,12 @@
 from ..properties.constant import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class GroupConcat(BaseFunction):
     obj: Literal['functions.GroupConcat'] = 'functions.GroupConcat'
-    property: Union[Constant, Property, BaseFunction, CastOperator]
+    property: Union[Constant, Property, BaseFunction, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/initcap.py

@@ -9,11 +9,12 @@
 from ..properties import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class InitCap(BaseFunction):
     obj: Literal['functions.InitCap'] = 'functions.InitCap'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/lower.py

@@ -9,11 +9,12 @@
 from ..properties import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Lower(BaseFunction):
     obj: Literal['functions.Lower'] = 'functions.Lower'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/min_max.py

@@ -8,11 +8,12 @@
 from ..functions.base import BaseFunction
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Max(BaseFunction):
     obj: Literal['functions.Max'] = 'functions.Max'
-    property: Union[Property, BaseFunction, CastOperator]
+    property: Union[Property, BaseFunction, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:
@@ -26,7 +27,7 @@ def to_sql(self) -> str:
 
 class Min(BaseFunction):
     obj: Literal['functions.Min'] = 'functions.Min'
-    property: Union[Property, BaseFunction, CastOperator]
+    property: Union[Property, BaseFunction, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/string_agg.py

@@ -12,11 +12,12 @@
 from ..properties import Array
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class StringAgg(BaseFunction):
     obj: Literal['functions.StringAgg'] = 'functions.StringAgg'
-    property: Union[Property, BaseFunction, Array, CastOperator, Distinct]
+    property: Union[Property, BaseFunction, Array, CastOperator, Distinct, Case]
     separator: str
     alias: str = None
 

duckql/functions/sum.py

@@ -8,11 +8,12 @@
 from ..functions.base import BaseFunction
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Sum(BaseFunction):
     obj: Literal['functions.Sum'] = 'functions.Sum'
-    property: Union[Property, BaseFunction, CastOperator]
+    property: Union[Property, BaseFunction, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/to_char.py

@@ -12,11 +12,12 @@
 from ..properties.constant import Constant
 from ..structures.cast_operator import CastOperator
 from ..structures.interval import Interval
+from ..structures.case import Case
 
 
 class ToChar(BaseFunction):
     obj: Literal['functions.ToChar'] = 'functions.ToChar'
-    property: Union[Property, Constant, BaseFunction, CastOperator, Interval]
+    property: Union[Property, Constant, BaseFunction, CastOperator, Interval, Case]
     format: str
     alias: str = None
 

duckql/functions/to_date.py

@@ -11,11 +11,12 @@
 from ..properties.property import Property
 from ..properties.constant import Constant
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class ToDate(BaseFunction):
     obj: Literal['functions.ToDate'] = 'functions.ToDate'
-    property: Union[Property, Constant, BaseFunction, CastOperator]
+    property: Union[Property, Constant, BaseFunction, CastOperator, Case]
     format: str
     alias: str = None
 

duckql/functions/unaccent.py

@@ -9,14 +9,15 @@
 from ..properties import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Unaccent(BaseFunction):
     """
     TODO: only in PostgreSQL
     """
     obj: Literal['functions.Unaccent'] = 'functions.Unaccent'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/upper.py

@@ -9,11 +9,12 @@
 from ..properties import Constant
 from ..properties.property import Property
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Upper(BaseFunction):
     obj: Literal['functions.Upper'] = 'functions.Upper'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/functions/weekday.py

@@ -9,11 +9,12 @@
 from ..properties.property import Property
 from ..properties.constant import Constant
 from ..structures.cast_operator import CastOperator
+from ..structures.case import Case
 
 
 class Weekday(BaseFunction):
     obj: Literal['functions.Weekday'] = 'functions.Weekday'
-    property: Union[Property, BaseFunction, Constant, CastOperator]
+    property: Union[Property, BaseFunction, Constant, CastOperator, Case]
     alias: str = None
 
     def to_sql(self) -> str:

duckql/structures/__init__.py

@@ -8,6 +8,7 @@
 from .between import Between
 from .operator import Operator
 from .cast_operator import CastOperator
+from .case import Case
 
 __all__ = [
     "Join",
@@ -19,5 +20,6 @@
     "Comparision",
     "Between",
     "Operator",
-    "CastOperator"
+    "CastOperator",
+    "Case"
 ]

duckql/structures/case.py

@@ -0,0 +1,42 @@
+from typing import List, Union, Optional
+
+from pydantic import BaseModel
+
+try:
+    from typing import Literal
+except ImportError:
+    from typing_extensions import Literal
+
+from ..base import BaseType
+from ..properties.property import Property
+from ..properties.constant import Constant
+from ..structures.comparision import Comparision
+from ..structures.operator import Operator
+from ..functions.base import BaseFunction
+
+
+class Case(BaseType):
+    # TODO: Docs!
+    class Condition(BaseModel):
+        when: Comparision
+        then: Union[BaseFunction, Property, Constant, Operator]
+
+        def __str__(self):
+            return f"WHEN {self.when} THEN {self.then}"
+
+    obj: Literal['structures.Case'] = 'structures.Case'
+    conditions: List[Condition]
+    alternative: Optional[Union[BaseFunction, Property, Constant]] = None
+    alias: str = None
+
+    def to_sql(self) -> str:
+        sql = "CASE " + " ".join(map(str, self.conditions))
+        if self.alternative:
+            sql = f"{sql} ELSE {self.alternative}"
+
+        sql = f"({sql} END)"
+
+        if self.alias is not None:
+            sql = f"{sql} AS {self.alias}"
+
+        return sql

duckql/structures/query.py

@@ -1,5 +1,6 @@
 from typing import List, Union
 
+from .case import Case
 from .cast_operator import CastOperator
 from ..functions.base import BaseFunction
 from pydantic import validator
@@ -25,7 +26,7 @@ class Config:
 
     obj: Literal['structures.Query'] = 'structures.Query'
     entity: Union[str, 'Query']
-    properties: List[Union[BaseFunction, Property, Distinct, CastOperator]]
+    properties: List[Union[BaseFunction, Property, Distinct, CastOperator, Case]]
     joins: List[Join] = []
     conditions: Union[Operator, Comparision] = None
     having: Union[Operator, Comparision] = None

duckql/structures/tests/test_case.py

@@ -0,0 +1,26 @@
+from duckql.properties.property import Property
+from duckql.properties.constant import Constant
+from duckql.structures.comparision import Comparision
+from duckql.structures.case import Case
+
+
+def test_simple():
+    my_structure = Case(
+        conditions=[
+            Case.Condition(
+                when=Comparision(
+                    properties=[
+                        Property(name='transactions.direction'),
+                        Constant(value='in')
+                    ],
+                    operation=Comparision.Operation.EQUAL
+                ),
+                then=Property(name='transactions.direction')
+            )
+        ],
+        alternative=Constant(value=0),
+        alias='test_case'
+    )
+
+    sql = "(CASE WHEN (transactions.direction = 'in') THEN transactions.direction ELSE 0 END) AS test_case"
+    assert str(my_structure) == sql

duckql/version.py

@@ -1 +1 @@
-__version__ = '0.9.1'
+__version__ = '0.10.0'