On 5/20/18 12:08 PM, ipkwena wrote:
I have started learning D and I am enjoying it so far.
How does one access the columns fields in a Mysql query results by the
column name. Currently I have to use the method as shown in a couple of
example by indexing array values (f being a struct variable):
Data f;
f.name = to!string(allrows[0][0]);
f.surname = to!string(allrows[0][1]);
f.title = to!string(allrows[0][2]);
I am using the mysql-native package or DB connectivity.
This is one of the weak spots of mysql-native -- the Row object has no
knowledge of the column names, so you have to "know" the order of the
columns you got from the server.
So what you can do is:
1. Use ResultRange instead of the Row interface. This provides a couple
of ways to use column names, .asAA to get all the data in a nice AA
format (they are still variants), .colNames to get the list of column
names ordered by the row fields, or .colNameIndicies which gives you an
AA of names to indices. Note that the AA generating versions will
allocate a lot of throw-away data.
2. Write a complicated serialization library like I did :) In this case,
I'm turning my ResultRange from a range of Rows to a range of the data
type I want, all serialized by column name instead of index.
Unfortunately, this is not open source so I can't share it.
At some point, I want to fix this part of mysql-native. I'm a bit
annoyed that we have to do Variants instead of writing directly to the
data type we are going to use anyway.
-Steve
