[Solved] This InfluxDB query returns no results:SELECT * FROM sensor_data WHERE time = now()What is the most likely reason? | Raspberry Pi

Raspberry Pi - Data Logging and Databases

This InfluxDB query returns no results:

SELECT * FROM sensor_data WHERE time = now()

What is the most likely reason?

Anow() function cannot be used in WHERE clause

BMissing measurement name

CUsing '=' with time instead of a range operator

DUsing '*' is not allowed in InfluxDB queries

Step-by-Step Solution

Solution:

Step 1: Understand time filtering in InfluxDB
Time comparisons with '=' are valid syntax but exact matches with now() return no results because timestamps use nanosecond precision and time advances continuously.
Step 2: Check query syntax
The measurement name is present, '*' is allowed, and now() can be used in WHERE clause.
Final Answer:
Using '=' with time instead of a range operator -> Option C
Quick Check:
Time filters need range operators [OK]

Quick Trick: Use > or < for time filters, not = [OK]

Common Mistakes:

MISTAKES

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