SQL select statement - returning records starting with variable length string
I am using an alphabetical sorting feature and need a SQL statement to return records beginning with a variable length string. However, records also need to be returned if there are periods, spaces, or dashes between any of the characters in the string.
For example, the value passed in could be "M" (easy). Or "MA" (in which case it need开发者_如何学Pythons to return records starting with "MA", "M.A", "M A", and "M-A"). Or "MAA", and so on.
This is the statement I have so far:
"SELECT * from table where LEFT(name," + value.Length + ")='" + value + "'"
But I can't work out how to get it to return results where there are periods, spaces or dashes in name
. Any help constructing the statement would be great.
If you're on MS SQL Server you could use the replace function if you have a reasonably finite set of "special" characters. You'll ruin index usage, but you'll likely do that anyway. For example:
SELECT
name,
i_will,
never_use,
select_star
FROM
My_Table MT
WHERE
REPLACE(REPLACE(REPLACE(name, '.', ''), ' ', ''), '-', '') LIKE @prefix + '%'
As you can see though, the statement quickly gets unwieldy as you add "_", "(", ")", etc...
Looks like a job for Regular Expressions. You can do it by returning some matching records in and applying Regex in ASP.NET & LINQ...or more efficiently, you can apply it to your SQL statement.
http://msdn.microsoft.com/en-us/magazine/cc163473.aspx
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