%s%t%f%i%s%d%n How to use when discuz data is being tuned

%s%t%f%i%s%d%n How to use when discuz data is being tuned
There are many such symbols in discuz, and I understand that they are substitution symbols, which seem to be written for convenience.
In addition Discuz SQL statement has a lot of parameters, the official did not give a clear statement, of course, the source code I can only see a half understand.
For example, sometimes in such sentences, followed by an array (), in parentheses also put some parameters, I do not know what these parameters are to represent what yo
------to solve the idea----------------------
Your PHP base still needs to improve AH ...
The following array is the parameter of the method Fetch_first, the value inside the array and the%t,%d in the preceding SQL statement: A placeholder like one by one corresponds to a
such as: Db::fetch_first ("select * from%t WHERE uid=%d", Array (' Common_member ', 1));
%t=pre_common_member (default execution db::table plus table prefix)
%d=1 (Intval is performed by default)

