I try to copy the content of a CSV file into my postgresql db and I get this error \"extra data after last expected column\".
The content of my CSV is
Now you have 7 fields.
You need to map those 6 fields from the CSV into 6 fields into the table.
You cannot map only 3 fields from csv when you have it 6 like you do in:
\COPY agency (agency_name, agency_url, agency_timezone) FROM 'myFile.txt' CSV HEADER DELIMITER ',';
All fields from the csv file need to to be mapped in the copy from command.
And since you defined csv , delimiter is default, you don't need to put it.