Clickhouse query with dictionary - database

Question

I imported the database of ontime airlines from here https://clickhouse.com/docs/en/getting-started/example-datasets/ontime/
Then I created a dictionary mapping the 2 digit airplane codes to company names like this:
id,code,company
1,UA,United Airlines
2,HA,Hawaiian Airlines
3,OO,SkyWest
4,B6,Jetblue Airway
5,QX,Horizon Air
6,YX,Republic Airway
7,G4,Allegiant Air
...
..
I used this query to generate it and it seems to be working:
CREATE DICTIONARY airlinecompany
(
id UInt64,
code String,
company String
)
PRIMARY KEY id
SOURCE(FILE(path '/var/lib/clickhouse/user_files/airlinenames.csv' format 'CSVWithNames'))
LAYOUT(FLAT())
LIFETIME(3600)
In the main database (ontime) Looks like this:
SELECT Reporting_Airline AS R_air
FROM ontime
GROUP BY R_air
LIMIT 4
┌─R_air─┐
│ UA │
│ HA │
│ OO │
│ B6 │
└───────┘
What I want to do is have a table that uses R_air's 2 code value and then checks it against the airlinecompany dict to create a mapping ie
R_Air Company
UA | United Airlines
HA | Hawaiian Airlines
00 | SkyWest
...
..
But I cant seem to form this query correctly:
SELECT
Reporting_Airline AS R_Air,
dictGetString('airlinecompany', 'company', R_Air) AS company
FROM ontime
GROUP BY R_Air
Received exception from server (version 22.3.3):
Code: 6. DB::Exception: Received from localhost:9000. DB::Exception: Cannot parse string 'UA' as UInt64: syntax error at begin of string. Note: there are toUInt64OrZero and toUInt64OrNull functions, which returns zero/NULL instead of throwing exception.: while executing 'FUNCTION dictGetString('airlinecompany' :: 1, 'company' :: 2, Reporting_Airline :: 0) -> dictGetString('airlinecompany', 'company', Reporting_Airline) String : 4'. (CANNOT_PARSE_TEXT)
What am I missing? I dont know why it thinks UA is a UInt64

Answer 1

LAYOUT = COMPLEX_KEY_HASHED
CREATE DICTIONARY airlinecompany
(
id UInt64,
code String,
company String
)
PRIMARY KEY code
SOURCE(FILE(path '/var/lib/clickhouse/user_files/airlinenames.csv' format 'CSVWithNames'))
LAYOUT(COMPLEX_KEY_HASHED())
LIFETIME(3600)
SELECT dictGet('airlinecompany', 'company', tuple('UA'))
┌─dictGet('airlinecompany', 'company', tuple('UA'))─┐
│ United Airlines │
└───────────────────────────────────────────────────┘
SELECT Reporting_Airline AS R_air,
dictGetString('airlinecompany', 'company', tuple(R_Air)) AS company
FROM ontime
LIMIT 4;
┌─R_Air─┬─company───────────┐
│ B6 │ Jetblue Airway │
│ G4 │ Allegiant Air │
│ HA │ Hawaiian Airlines │
│ OO │ SkyWest │
└───────┴───────────────────┘