Odtnhj

In one of our erlang project we are loading data from mysql database using mysql-otp as below -

ok, Columns, Rows = mysql:query(ConnectionPid, <<"SELECT * FROM credentials WHERE username = ?">>, [Username])

Now Columns is a list of binaries consisting all column names and Rows are the list of list of records.

For eg.

Columns = [<<"id">>, <<"username">>, <<"password">>, <<"is_active">>]
Rows = [[1,"test_user_1", "password", 'Y'], [2, "test_user_2", "password", 'Y']]

Now we would like to cache the mysql records into ets tables on load. So we will need to create the records from the above two lists.

For eg. we have the below record declaration

-record(credentials, id, username, password, is_active).

So how to create the list of credentials record from the above two list Columns and Rows. Any idea?

Edits

we can't use list_to_tuple function as there might be variable number of elements in the Rows list than credentials

If your data in Rows is consistent in the way that the values in [Id,Username,Password,IsActive|_] can always be expected to be orderly and other extra values will be tailing them, you won't need Columns as mentioned by @7stud in the post's comments.

Here is how I'd do with list comprehension:

Creds = [ #credentials
 id=Id,
 username=Usr,
 password=Pw,
 is_active=Act || [Id,Usr,Pw,Act|_] <- Rows ]

The _ means that we ignore whatever extra values there might be that won't fit into credentials's shape.