Question

I’m trying to build an asp.net page using c# that will query a column in an Oracle database that has 20,000 rows.

I want to display all rows that match this regular expression pattern “[\r\n]$”.(should only have about 5 rows that match this pattern)

The version of Oracle we use does not support regex so I need to find a way to do this in c# but I’m not sure how do that.

Answer 1

First, start by figuring out what the regular expression does.

Let’s break this one down:

[\r\n]$

The brackets [] give you a character class and says “match one of these characters.” Thus [\r\n] says match \r (carriage return) or \n (line break). The $ is an anchor and says “match at the end of the string.” Thus, the regular expression says “match a carriage return or line break at the end of the string.”

Now, can you translate that into SQL? For this you need something like

SELECT * FROM TABLE
WHERE
    SOMECOLUMN LIKE '%'||CHR(13)||CHR(10) OR
    SOMECOLUMN LIKE '%'||CHR(13)

(Sorry, my Oracle is weak but this is a close first approximation.)

If not, can you get the data out of your table (SELECT * FROM TABLE) and run this regex locally in .NET? Twenty-thousand rows is not that much to just pull the whole thing into memory and run it locally.