StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>Here is an example:</p> <pre><code>var user1 = new User {Name = "steve", Age = 28}; var user2 = new User {Name = "foobar", Age = 28}; Expression<Func<User, bool>> expression1 = t => t.Name == "steve"; Expression<Func<User, bool>> expression2 = t => t.Age == 28; var invokedExpression = Expression.Invoke(expression2, expression1.Parameters.Cast<Expression>()); var result = Expression.Lambda<Func<User, bool>>(Expression.And(expression1.Body, invokedExpression), expression1.Parameters); Console.WriteLine(result.Compile().Invoke(user1)); // true Console.WriteLine(result.Compile().Invoke(user2)); // false </code></pre> <p>You can reuse this code via extension methods: </p> <pre><code>class User { public string Name { get; set; } public int Age { get; set; } } public static class PredicateExtensions { public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expression1,Expression<Func<T, bool>> expression2) { InvocationExpression invokedExpression = Expression.Invoke(expression2, expression1.Parameters.Cast<Expression>()); return Expression.Lambda<Func<T, bool>>(Expression.And(expression1.Body, invokedExpression), expression1.Parameters); } } class Program { static void Main(string[] args) { var user1 = new User {Name = "steve", Age = 28}; var user2 = new User {Name = "foobar", Age = 28}; Expression<Func<User, bool>> expression1 = t => t.Name == "steve"; Expression<Func<User, bool>> expression2 = t => t.Age == 28; var result = expression1.And(expression2); Console.WriteLine(result.Compile().Invoke(user1)); Console.WriteLine(result.Compile().Invoke(user2)); } } </code></pre>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

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