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Code Block
$ odb sql 'select count(*) where varno=2' -i $odbfile

 

count(*) is an aggregation function. Based on the other keys present in the SQL query (here: filtering to select only the temperature entries), each population of identified entries see the data subjected to the aggregation function.

 

Count the number of temperature records, this time per station identifier, where the observation values are not missing:

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Code Block
$ odb sql 'select count(*), statid where varno=2 and obsvalue is not NULL' -i $odbfile

 

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Get, at one station, the observation count and average temperature observation value by pressure level bins of 100 hPa each, showing also the average pressure in each pressure bin:

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Code Block
$ odb sql 'select count(*), avg(fg_depar), floor(vertco_reference_1/10000.0), avg(vertco_reference_1/100.0) where varno=2 and statid="10739" and fg_depar is not null' -i $odbfile

 

List See full  list of aggregation functions available, other than count(*):

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aggregate functions.

Get, at one station, the observation count and mean observation minus first-guess departure for meridional wind and zonal wind near 500 hPa:

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