Trim a decimal to 2 places Bigquery

Question

I am currently running a query that runs a sum function and also divides this number. Currently I get values like 0.0904246741698848, and 1.6419814808335567. I want these decimals to be trimmed to 2 spaces past the decimal point. Their schema is a float. Here is my code. Thanks for the help.

#standardSQL
SELECT
  Serial,
  MAX(createdAt) AS Latest_Use,
  SUM(ConnectionTime/3600) as Total_Hours,
  COUNT(DISTINCT DeviceID) AS Devices_Connected
FROM `dataworks-356fa.FirebaseArchive.Firebase_ConnectionInfo`
WHERE PeripheralType = 1 or PeripheralType = 2 or PeripheralType = 12
GROUP BY Serial
ORDER BY Latest_Use DESC

Answer 1

#standardSQL
WITH `data` AS (
  SELECT 0.0904246741698848  AS val UNION ALL
  SELECT 1.6419814808335567 
)
SELECT val, ROUND(val, 2) AS rounded_val
FROM `data`   

for example, assuming your want apply this to your Total_Hours column :

#standardSQL
SELECT
  Serial,
  MAX(createdAt) AS Latest_Use,
  ROUND(SUM(ConnectionTime/3600),2) AS Total_Hours,
  COUNT(DISTINCT DeviceID) AS Devices_Connected
FROM `dataworks-356fa.FirebaseArchive.Firebase_ConnectionInfo`
WHERE PeripheralType = 1 OR PeripheralType = 2 OR PeripheralType = 12
GROUP BY Serial
ORDER BY Latest_Use DESC

Answer 2

You can always use the round() function.
If you are looking for precision after decimal (as using round will round-off the values) you can use substr(str(value),precision) which will give exact output after decimal.

Answer 3

I found that rounding was problematic if my data had a whole number such as 2.00 and I needed all of my data to reflect 2 decimal places as these were for prices that end up getting displayed. Big Query was returning 2.0 no matter what I specified to round to using ROUND.

Assuming you're working with data that never surpasses 2 decimal places, and it is stored as a STRING, this code will work (if it's more decimal places, add another 0 to the addition for each space).

FORMAT("%.*f",2,CAST(GROSS_SALES_AMT AS FLOAT64) + .0001)

Answer 4

This will take a float in BigQuery and format it with two decimal points.

CAST(SUM(ConnectionTime/3600) AS STRING FORMAT '999,999.99')

Note: Add a $ for currency ($999,999.99).

Example: