-
Notifications
You must be signed in to change notification settings - Fork 1
/
hello_world_transform.py
86 lines (63 loc) · 2.92 KB
/
hello_world_transform.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
from mETL.etl.raw_model import RawModel
from mETL.etl.transform_database import TransformDatabase
from mETL.column_data_type import IntegerColumn, TextColumn
from mETL.etl.transform import Transform
from mETL.etl.query import Query
def level_zero():
class TestDatabase(TransformDatabase):
class TestTable(RawModel):
num_col = IntegerColumn()
text_col = TextColumn()
test_table = TestTable(table_name='test_table')
test_database = TestDatabase(queue_name='mETL.fifo', database='metl')
test_database.create_all_tables()
message = test_database.queue.read_from_queue()
test_database.process_queue_message(message)
def level_one():
class ColorsDatabase(TransformDatabase):
class Colors(RawModel):
id = IntegerColumn()
name = TextColumn()
class Users(RawModel):
id = IntegerColumn()
name = TextColumn()
favorite_color_id = IntegerColumn()
color_table = Colors(table_name='colors')
user_table = Users(table_name='users')
class FavoriteColors(Transform):
def transform(self):
return '''
select users.id as user_id, users.name, favorite_color_id, colors.name as favorite_color_name
from colors
join users
on colors.id = users.favorite_color_id
'''
favorite_colors = FavoriteColors(table_name='favorite_colors', source_tables=[color_table, user_table])
colors_database = ColorsDatabase(queue_name='mETL.fifo', database='metl')
colors_database.create_all_tables()
message = colors_database.queue.read_from_queue()
colors_database.process_queue_message(message)
def level_two():
class ColorsDatabase(TransformDatabase):
class Colors(RawModel):
id = IntegerColumn()
name = TextColumn()
class Users(RawModel):
id = IntegerColumn()
name = TextColumn()
favorite_color_id = IntegerColumn()
colors = Colors(table_name='colors')
users = Users(table_name='users')
favorite_colors = Transform(table_name='favorite_colors', source_tables=[colors, users])
favorite_colors.transform = (Query()
.select(user_id=users.id, name=users.name,
favorite_color_id=colors.id, favorite_color_name=colors.name)
.from_table(users)
.join(colors, how='inner', left_on=users.favorite_color_id, right_on=colors.id)
.build)
colors_database = ColorsDatabase(queue_name='mETL.fifo', database='metl')
colors_database.create_all_tables()
message = colors_database.queue.read_from_queue()
colors_database.process_queue_message(message)
if __name__ == '__main__':
level_two()