LINQ rules!

Here’s an example of a small refactoring I did today using LINQ’s features in C#. I had this method that simply constructs a WHERE clause for a SQL statement using an IList of table prefixes:
private string getWhereClauseForTablePrefixes(IList<String> tablePrefixes) { var where = ""; if (tablePrefixes.Count > 0) { where += " where "; var enumerator = tablePrefixes.GetEnumerator(); enumerator.MoveNext(); while (true) { where += "table_name like '" + enumerator.Current + "%'"; if (enumerator.MoveNext()) { where += " or "; } else { break; } } } return where; }

So, e.g. for a list containing A and B the method returned where table_name like 'A%' or table_name like 'B%'. Using the Select extension method on IList, the method now looks like this:

private string getWhereClauseForTablePrefixes(IList<String> tablePrefixes) { var where = ""; if (tablePrefixes.Count > 0) { where += " where "; where += String.Join(" OR ", tablePrefixes.Select(prefix => "table_name like '" + prefix + "%'")); } return where; }

Simple and concise! 🙂

Ãœber uns Stefan

Polyglot Clean Code Developer

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