**# AGGREGATE FUNCTIONS**

     count(*) -- how many row's in the database
     count(column name) -- count's all the NuN Values
     min(amount) as min_amount -- function of the minimum amount
     max(amount) as max_amount -- function of the maximum amount
     avg(amount) as avg_amount -- function of the average amount
     floor(avg(amount)) as floor_avg -- round's down the decimals
     ceiling(avg(amount)) as ceiling_avg -- round's up the decimals
     round(amount) -- it gives you the round it amount
     length(k_simbol) -- gives you the length of the column
     concat(order_id,account_id) -- concatenate the 2 columns
     lower(k_simbol) -- gives you the lowercases from the column
     upper(k_symbol) -- gives you the uppercase from the column
     left(k_symbol,2) -- gives you the first 2 letter's of the string's
     ltrim(k_symbol) -- remove spaces from the beginning of the string's
     rtrim(k_symbol) -- remove spaces from the end of the string's
     substring_index(issued,':',1)
     -- in this function, it run's the row from the column "issued",
     -- tell's to stop on the on the first ":"
     substring_index(issued,':',2)
      -- in this function, it run's the row from the column "issued",
      -- tell's to stop on the on the second ":"