Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I would suggest using the <a href="http://ruby-doc.org/stdlib-1.9.2/libdoc/csv/rdoc/CSV.html#method-i-header_row-3F" rel="nofollow">CSV::header_row</a> function to perform the check, and raising an error if it's not what you expect. Something like:</p> <pre><code>def ReadLongFile(longFile) CSV.foreach(longFile, :headers =&gt; true, :return_headers =&gt; true, :col_sep =&gt; '|') do |row| if row.header_row? then raise ArgumentError, "Bad headers" unless header_sane?(row) end # Otherwise do the processing end end </code></pre> <p>Your implemenation of <code>header_sane?</code> will perform the validation that you need to ensure the file is what you expect it to be. Your calling code can rescue the ArgumentError if it can recover from it, or just let it fail :-)</p> <p>Note: Updated to reflect error noted in the comments below. Be sure to set the :return_headers option when calling <a href="http://ruby-doc.org/stdlib-1.9.2/libdoc/csv/rdoc/CSV.html#method-c-foreach" rel="nofollow">CSV::foreach</a>.</p> <p>If you are worried about the minimal overhead of calling header_row? for each of the row entries, you can construct a CSV instance and use <a href="http://ruby-doc.org/stdlib-1.9.2/libdoc/csv/rdoc/CSV.html#method-i-shift" rel="nofollow">shift</a> to manually check the first row before continuing. For instance:</p> <pre><code>def ReadLongFile(longFile) File.open(longFile) do |file| reader = CSV.new(file, {:col_sep =&gt; '|', :headers =&gt; true, :return_headers =&gt; true}) header_row = reader.shift raise ArgumentError, "Bad file headers" unless header_sane?(header_row) reader.each do |row| p row end end end </code></pre> <p>Implemented as above, the following behavior holds true:</p> <pre><code>[4] pry(main)&gt; def header_sane? row [4] pry(main)* true [4] pry(main)* end =&gt; nil [5] pry(main)&gt; ReadLongFile("file.csv") #&lt;CSV::Row "date":"2010-01-01" "time":"07:00:00" "account":"A1"&gt; #&lt;CSV::Row "date":"2010-01-01" "time":"07:00:01" "account":"A2"&gt; =&gt; nil [6] pry(main)&gt; def header_sane? row [6] pry(main)* false [6] pry(main)* end =&gt; nil [7] pry(main)&gt; ReadLongFile("file.csv") ArgumentError: Bad file headers from (pry):7:in `block in ReadLongFile' </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POCheck file header and then loop through
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USRon Dahlgren
    1. USRon Dahlgren
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POCheck file header and then loop through
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    1. COThis is incorrect. First `is_header?` in your function should be `header_row?`. Also, it is necessary to set `:return_headers` to true.
      singulars
      1. PO
      1. USidealistikz
    2. CO@idealistikz updated accordingly - thanks!
      singulars
      1. PO
      1. USRon Dahlgren
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload