Query some part on each record.

rubyonrails-talk
#1

I would like to ask you this question
suppose that I've 1 record which contains very long contents like

Big_Row_Table

#2

i don't wann disappoint, but i think you'll have to query the whole
entry "very long contents" and cut off the tail.

  GetsomePart.Big_Row[0..3]

if anyone knows a better solution (one that offers more performance),
let me know.

#3

MaD wrote:

i don't wann disappoint, but i think you'll have to query the whole
entry "very long contents" and cut off the tail.

  GetsomePart.Big_Row[0..3]

if anyone knows a better solution (one that offers more performance),
let me know.

Thx , Mad :smiley:
Any other solution? :slight_smile:

#4

i don't wann disappoint, but i think you'll have to query the whole
entry "very long contents" and cut off the tail.

GetsomePart.Big_Row[0..3]

if anyone knows a better solution (one that offers more performance),
let me know.

Well I don't know if it's a good idea, probably database dependent
etc. etc. but Foo.find some_id, :select => 'substring(bar,0, 5) as
bar, id, ...'
Database almost certainly still needs to go and load that entire
column so I doubt it will make a huge difference.

Fred

#5

You could have another column in the table, containing the short version.

#6

Would you please tell more details on this solution? Fred I'm not
clearly understand this.

There's not a whole lot to it - use a select clause to control what is
fetched by the database.

Fred