For exchange one currency to another one I use:
https://developer.yahoo.com/yql/console/?q=show%20tables&env=store://datatables.org/alltableswithkeys#h=select+*+from+yahoo.finance.xchange+where+pair+in+(%22USDAZN%22)
this link, but how can I get Brent oil rate in JSON format with this API? Can anyone help me to build this link?
Try this query
https://developer.yahoo.com/yql/console/?q=select%20*%20from%20yahoo.finance.quote%20where%20symbol%20in%20(%22YHOO%22%2C%22AAPL%22%2C%22GOOG%22%2C%22MSFT%22)&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys#h=select+*+from+yahoo.finance.quote+where+symbol+in+(%22BNO%22)
It gives all the data regarding Brent(United States Brent Oil, If thats what you want or simply change the symbol).