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copied!<p>So what you're looking for is an implementation of a predicate builder that can take any number of expressions and OR them together. Here is an implementation that will work with any query provider:</p> <pre><code>public static class PredicateBuilder { public static Expression<Func<T, bool>> True<T>() { return f => true; } public static Expression<Func<T, bool>> False<T>() { return f => false; } public static Expression<Func<T, bool>> Or<T>( this Expression<Func<T, bool>> expr1, Expression<Func<T, bool>> expr2) { var secondBody = expr2.Body.Replace(expr2.Parameters[0], expr1.Parameters[0]); return Expression.Lambda<Func<T, bool>> (Expression.OrElse(expr1.Body, secondBody), expr1.Parameters); } public static Expression<Func<T, bool>> And<T>( this Expression<Func<T, bool>> expr1, Expression<Func<T, bool>> expr2) { var secondBody = expr2.Body.Replace(expr2.Parameters[0], expr1.Parameters[0]); return Expression.Lambda<Func<T, bool>> (Expression.AndAlso(expr1.Body, secondBody), expr1.Parameters); } } </code></pre> <p>which uses:</p> <pre><code>internal class ReplaceVisitor : ExpressionVisitor { private readonly Expression from, to; public ReplaceVisitor(Expression from, Expression to) { this.from = from; this.to = to; } public override Expression Visit(Expression node) { return node == from ? to : base.Visit(node); } } public static Expression Replace(this Expression expression, Expression searchEx, Expression replaceEx) { return new ReplaceVisitor(searchEx, replaceEx).Visit(expression); } </code></pre> <p>This allows you to take any two expressions and create a new expression that is the result of ORing them together.</p> <pre><code>List<Tuple<string, string>> list = CreateList(); var finalExpression = list.Aggregate(PredicateBuilder.False<Data>(), (predicate, pair) => predicate.Or(n => n.Item1 == pair.Item2)); var query = data.Where(finalExpression); </code></pre>

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