using System;

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// Example entity

[Table("Student", "s")]

public class Student

{

    [Column("Id", "StudentId")]

    public int Id { get; set; }

​

    [Column("UserId", "MainUser")]

    public int UserId { get; set; }

​

    // INNER JOIN with Inquiry using dynamic condition

    [Join("Inquiry", "s.Id = i.StudentId AND s.UserId = i.UserId", JoinType.Inner, "i")]

    public Inquiry Inquiry { get; set; }

​

    // LEFT JOIN with Country using a single condition

    [Join("Country", "s.CountryId = c.Id", JoinType.Left, "c")]

    public Country Country { get; set; }

}

​

[Table("Inquiry", "i")]

public class Inquiry

{

    [Column("UserId", "InquiryUser")]

    public int UserId { get; set; }

}

​

[Table("Country", "c")]

public class Country

{

    [Column("Name", "CountryName")]

    public string Name { get; set; }

}

​

​

​

​

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// Attributes

[AttributeUsage(AttributeTargets.Class, Inherited = false)]

public class TableAttribute : Attribute

{

    public string TableName { get; }

    public string Alias { get; }

​

    public TableAttribute(string tableName, string alias = null)

    {

        TableName = tableName;

        Alias = alias;

    }

}

​

[AttributeUsage(AttributeTargets.Property, Inherited = false)]

public class ColumnAttribute : Attribute

{

    public string ColumnName { get; }

    public string Alias { get; }

​

    public ColumnAttribute(string columnName, string alias = null)

    {

        ColumnName = columnName;

        Alias = alias;

    }

}

​

[AttributeUsage(AttributeTargets.Property, Inherited = false)]

public class JoinAttribute : Attribute

{

    public string ForeignTable { get; }

    public JoinType JoinType { get; }

    public string Condition { get; }

    public string Alias { get; }

​

    // Constructor for fully dynamic join conditions

    public JoinAttribute(string foreignTable, string condition, JoinType joinType = JoinType.Inner, string alias = null)

    {

        ForeignTable = foreignTable;

        JoinType = joinType;

        Condition = condition;

        Alias = alias;

    }

}

​

// Enum

public enum JoinType

{

    Inner,

    Left

}

​

​