Repodb: Bug: UnaryExpression: Add support for && and || operators in the expressions

Created on 5 Mar 2020 · 6Comments · Source: mikependon/RepoDB

Hi. First of all, I want to thank you for this project, I really like the idea of a tool that's somewhere in-between Dapper and EntityFramework :)

But currently, it's possible to make queries only out of very simple expressions (e.g. no conditional statements).
I'd like to have this code working:

 await _repo.SearchAsync<MyEntity>(s => s.Prop1 == 3 && s.Prop2 == "test");

But it says "System.NotSupportedException: Operation: Expression 'AndAlso' is currently not supported."

Any plans for adding such functionality in the future?

UPD. I'm testing it on .net core 3.0, RepoDb.Mysql

Fixed bug deployed priority todo

Source

klym1

Most helpful comment

Thanks for the fast reply.

Yes, I'm using QueryAsync method like this:

public async Task<List<TEntity>> SearchAsync<TEntity>(Expression<Func<TEntity, bool>> expression) where TEntity : class
        {
            using var connection = _connectionFactory.GetConnection();
            return (await connection.QueryAsync(expression)).ToList();
        }

I was not fully precise when I provided an example of expression. In my case it also contains negation of a bool property:

await _repo.SearchAsync<MyEntity>(s => s.Prop1 == prop1 && !s.Prop2)

Without ! it works just fine.

klym1 on 6 Mar 2020

👍2

All 6 comments

RepoDb had thorough support on query tree expression.

See the codes here at 54. That address your concern, or, let me check this.

mikependon on 5 Mar 2020

Also, the codes here mimics yours.

Btw, would you be able to share your model?

I tested this one using the codes below and it works.

[TestMethod]
public void TestMySqlConnectionQueryAsyncViaExpression()
{
    // Setup
    var table = Database.CreateCompleteTables(1).First();

    using (var connection = new MySqlConnection(Database.ConnectionString))
    {
        // Act
        var result = connection.QueryAsync<CompleteTable>(e => e.ColumnInt == 0 &&
            e.ColumnVarchar == "Test").Result.FirstOrDefault();

        // Assert
        Helper.AssertPropertiesEquality(table, result);
    }
}

I would assume that you are using the underlying method QueryAsync for your SearchAsync.

mikependon on 6 Mar 2020

Thanks for the fast reply.

Yes, I'm using QueryAsync method like this:

public async Task<List<TEntity>> SearchAsync<TEntity>(Expression<Func<TEntity, bool>> expression) where TEntity : class
        {
            using var connection = _connectionFactory.GetConnection();
            return (await connection.QueryAsync(expression)).ToList();
        }

I was not fully precise when I provided an example of expression. In my case it also contains negation of a bool property:

await _repo.SearchAsync<MyEntity>(s => s.Prop1 == prop1 && !s.Prop2)

Without ! it works just fine.

klym1 on 6 Mar 2020

👍2

Great, I have to look at this then. This is a UnaryExpression then I could not say that why RepoDb fails to it. I have to debug it first.

Thank you for this and will definitely will get back to you.

But as an alternative fix, you can use the code below.

await _repo.SearchAsync<MyEntity>(s => s.Prop1 == prop1 && s.Prop2 == false);

By the way, always use the AsList() method over ToList() method. It cast things if it is castable, that is much more faster when converting each item ;)

mikependon on 6 Mar 2020

Just verified this one and this is a bug. It is very easy to replicate.