-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathCreating tables and intial cleaning.sql
129 lines (106 loc) · 2.56 KB
/
Creating tables and intial cleaning.sql
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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
--creating table so that import data from "divvy-tripdata"
CREATE TABLE january_2021 (
ride_id VARCHAR(250),
rideable_type VARCHAR(250),
started_at TIMESTAMP,
ended_at TIMESTAMP,
start_station_name VARCHAR(250),
start_station_id VARCHAR(250),
end_station_name VARCHAR(250),
end_station_id VARCHAR(250),
start_lat FLOAT,
start_lng FLOAT,
end_lat FLOAT,
end_lng FLOAT,
member_casual VARCHAR(250)
)
CREATE TABLE february_2021 (
ride_id VARCHAR(250),
rideable_type VARCHAR(250),
started_at TIMESTAMP,
ended_at TIMESTAMP,
start_station_name VARCHAR(250),
start_station_id VARCHAR(250),
end_station_name VARCHAR(250),
end_station_id VARCHAR(250),
start_lat FLOAT,
start_lng FLOAT,
end_lat FLOAT,
end_lng FLOAT,
member_casual VARCHAR(250)
)
.
.
.
.
.
-- creating table upto december_2021
CREATE TABLE december_2021 (
ride_id VARCHAR(250),
rideable_type VARCHAR(250),
started_at TIMESTAMP,
ended_at TIMESTAMP,
start_station_name VARCHAR(250),
start_station_id VARCHAR(250),
end_station_name VARCHAR(250),
end_station_id VARCHAR(250),
start_lat FLOAT,
start_lng FLOAT,
end_lat FLOAT,
end_lng FLOAT,
member_casual VARCHAR(250)
-- creating table for importing all data into a single table
CREATE TABLE all_months (
ride_id VARCHAR(250),
rideable_type VARCHAR(250),
started_at TIMESTAMP,
ended_at TIMESTAMP,
start_station_name VARCHAR(250),
start_station_id VARCHAR(250),
end_station_name VARCHAR(250),
end_station_id VARCHAR(250),
start_lat FLOAT,
start_lng FLOAT,
end_lat FLOAT,
end_lng FLOAT,
member_casual VARCHAR(250)
)
-- Using UNION ALL command to import all the months from january_2021 to december_2021 in all_months table
INSERT INTO all_months
SELECT * FROM january_2021
UNION ALL
SELECT * FROM february_2021
UNION ALL
SELECT * FROM march_2021
UNION ALL
SELECT * FROM april_2021
UNION ALL
SELECT * FROM may_2021
UNION ALL
SELECT * FROM june_2021
UNION ALL
SELECT * FROM july_2021
UNION ALL
SELECT * FROM august_2021
UNION ALL
SELECT * FROM september_2021
UNION ALL
SELECT * FROM october_2021
UNION ALL
SELECT * FROM november_2021
UNION ALL
SELECT * FROM december_2021;
-- counting the nulls in start_station_name
SELECT COUNT(*) FROM all_months
WHERE start_station_name IS NULL
-- counting the nulls in end_station_name
SELECT COUNT(*) FROM all_months
WHERE end_station_name IS NULL
-- counting nulls in end_lat
SELECT COUNT(*) FROM all_months
WHERE end_lat IS NULL
-- counting nulls in end_lng
SELECT COUNT(*) FROM all_months
WHERE end_lng IS NULL
-- time in minutes
select FLOOR(EXTRACT(EPOCH FROM(ended_at - started_at)/60)) from all_months