Databases
StackOverflow2013
Postsdbo
POMatch a row with fixed columns as long as possible
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POMatch a row with fixed columns as long as possible
    primarykey
    data
    text
    <p>I'm going to parse a position base file from a legacy system. Each column in the file has a fixed column width and each row can maximum be 80 chars long. The problem is that you don't know how long a row is. Sometime they only have filled in the first five columns, and sometimes all columns are used.</p> <p>If I KNOW that all 80 chars where used, then I simple could do like this:</p> <pre><code>^\s* (?&lt;a&gt;\w{3}) (?&lt;b&gt;[ \d]{2}) (?&lt;c&gt;[ 0-9a-fA-F]{2}) (?&lt;d&gt;.{20}) ... </code></pre> <p>But the problem with this is that if the last columns is missing, the row will not match. The last column can even be less number of chars then the maximum of that column.</p> <p>See example</p> <pre><code>Text to match a b c d "AQM45A3A text " =&gt; AQM 45 A3 "A text " //group d has 9 chars instead of 20 "AQM45F5" =&gt; AQM 45 F5 //group d is missing "AQM4" =&gt; AQM 4 //group b has 1 char instead of 2 "AQM4 ASome Text" =&gt; AQM 4 A "Some Text" //group b and c only uses one char, but fill up the gap with space "AQM4FSome Text" =&gt; No match, group b should have two numbers, but it is only one. "COM*A comment" =&gt; Comments do not match (all comments are prefixed with COM*) " " =&gt; Empty lines do not match </code></pre> <p>How should I design the Regular Expression to match this?</p> <p><strong>Edit 1</strong></p> <p>In this example, EACH row that I want to parse, is starting with AQM</p> <ul> <li>Column a is always starting at position 0 </li> <li>Column b is always starting at position 3 </li> <li>Column c is always starting at position 5 </li> <li>Column d is always starting at position 7</li> </ul> <p>If a column is not using all its space, is files up with spaces Only the last column that is used can be trimed</p> <p><strong>Edit 2</strong> To make it more clearer, I enclose here soem exemple of how the data might look like, and the definition of the columns (note that the examples I have mentioned earlier in the question was heavily simplified)</p> <p><img src="https://i.stack.imgur.com/f0366.png" alt="Example for AQM"> <img src="https://i.stack.imgur.com/Lhobn.png" alt="Definition for AQM"></p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USmagol
    1. USmagol
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POMatch a row with fixed columns as long as possible
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYour requirements are not really clear. Which rows of your example should match and which shouldn't? And why?
      singulars
      1. POMatch a row with fixed columns as long as possible
      1. USmusefan
    2. COSorry. All the rows in the example should match. The task is to get all columns that are present on each row. I add some more examples to show row that do not match
      singulars
      1. POMatch a row with fixed columns as long as possible
      1. USmagol
    3. COThe main problem in your situation is the lack of any clear separator between the columns, what could qualify a certain character to be in this or that column since character number in each column is variable ?
      singulars
      1. POMatch a row with fixed columns as long as possible
      1. USIbrahim Najjar
 

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