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I am trying to work with a database that I barly know and I need to know column names of a table:

Here is what I tried:

client = DataFrameClient(host, 8086, username, password, "marketdata")
client.switch_database('marketdata')
print(client.query("show measurements"))
# ResultSet({'('measurements', None)': [{'name': 'bookTicker'}]})

query = "SELECT COUNT(DISTINCT bookTicker) FROM information_schema.columns WHERE table_schema = 'marketdata'"

dataframes = client.query(query)

raise InfluxDBClientError(self.error)
influxdb.exceptions.InfluxDBClientError: retention policy not found: information_schema

I also tried:

query = "select * from bookTicker limit 10"

raise ChunkedEncodingError(e)
requests.exceptions.ChunkedEncodingError: ("Connection broken: InvalidChunkLength(got length b'', 0 bytes read)", InvalidChunkLength(got length b'', 0 bytes read))
Abolfazl
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1 Answers1

3

You are trying to use SQL knowledge for nonSQL InfluxDB.

InfluxDB doesn't have concept of columns, but tags (in SQL meaning something like indexed column) and fields (something like a column).

You can explore them with the queries:

SHOW TAG KEYS [ON <database_name>] [FROM_clause] [WHERE <tag_key> ['<tag_value>' | <regular_expression>]] [LIMIT_clause] [OFFSET_clause]

https://docs.influxdata.com/influxdb/v1.7/query_language/schema_exploration/#show-tag-keys

SHOW FIELD KEYS [ON <database_name>] [FROM <measurement_name>]

https://docs.influxdata.com/influxdb/v1.7/query_language/schema_exploration/#show-field-keys

Jan Garaj
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