Add typed join specification builder syntax

AmalgamationTool/DynamORM.Amalgamation.cs

@@ -7190,6 +7190,12 @@ namespace DynamORM
                 /// <returns>Builder instance.</returns>
                 IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null, DynamicJoinType joinType = DynamicJoinType.Inner);
 
+                /// <summary>Add typed join using join-spec builder syntax (<c>As()</c>, join kind and <c>On()</c>).</summary>
+                /// <typeparam name="TRight">Joined mapped entity type.</typeparam>
+                /// <param name="specification">Join specification builder callback.</param>
+                /// <returns>Builder instance.</returns>
+                IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Func<TypedJoinBuilder<T, TRight>, TypedJoinBuilder<T, TRight>> specification);
+
                 /// <summary>Add INNER JOIN using typed ON predicate.</summary>
                 IDynamicTypedSelectQueryBuilder<T> InnerJoin<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null);
 
@@ -7402,6 +7408,64 @@ namespace DynamORM
                     return source;
                 }
             }
+            /// <summary>Typed join specification builder used by typed fluent select queries.</summary>
+            /// <typeparam name="TLeft">Left side mapped type.</typeparam>
+            /// <typeparam name="TRight">Right side mapped type.</typeparam>
+            public class TypedJoinBuilder<TLeft, TRight>
+            {
+                internal TypedJoinBuilder()
+                {
+                    JoinType = DynamicJoinType.Inner;
+                }
+                /// <summary>Gets join alias.</summary>
+                public string Alias { get; private set; }
+
+                /// <summary>Gets join type.</summary>
+                public DynamicJoinType JoinType { get; private set; }
+
+                /// <summary>Gets ON predicate.</summary>
+                public Expression<Func<TLeft, TRight, bool>> OnPredicate { get; private set; }
+
+                /// <summary>Sets join alias.</summary>
+                public TypedJoinBuilder<TLeft, TRight> As(string alias)
+                {
+                    Alias = alias;
+                    return this;
+                }
+                /// <summary>Sets INNER JOIN.</summary>
+                public TypedJoinBuilder<TLeft, TRight> Inner()
+                {
+                    JoinType = DynamicJoinType.Inner;
+                    return this;
+                }
+                /// <summary>Sets LEFT JOIN.</summary>
+                public TypedJoinBuilder<TLeft, TRight> Left()
+                {
+                    JoinType = DynamicJoinType.Left;
+                    return this;
+                }
+                /// <summary>Sets RIGHT JOIN.</summary>
+                public TypedJoinBuilder<TLeft, TRight> Right()
+                {
+                    JoinType = DynamicJoinType.Right;
+                    return this;
+                }
+                /// <summary>Sets FULL JOIN.</summary>
+                public TypedJoinBuilder<TLeft, TRight> Full()
+                {
+                    JoinType = DynamicJoinType.Full;
+                    return this;
+                }
+                /// <summary>Sets ON predicate.</summary>
+                public TypedJoinBuilder<TLeft, TRight> On(Expression<Func<TLeft, TRight, bool>> predicate)
+                {
+                    if (predicate == null)
+                        throw new ArgumentNullException("predicate");
+
+                    OnPredicate = predicate;
+                    return this;
+                }
+            }
             /// <summary>Compatibility and convenience extensions for typed joins.</summary>
             public static class TypedJoinExtensions
             {
@@ -10742,6 +10806,19 @@ namespace DynamORM
                         base.Join(x => joinExpr);
                         return this;
                     }
+                    public IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Func<TypedJoinBuilder<T, TRight>, TypedJoinBuilder<T, TRight>> specification)
+                    {
+                        if (specification == null)
+                            throw new ArgumentNullException("specification");
+
+                        TypedJoinBuilder<T, TRight> spec = specification(new TypedJoinBuilder<T, TRight>());
+                        if (spec == null)
+                            throw new ArgumentException("Join specification cannot resolve to null.", "specification");
+                        if (spec.OnPredicate == null)
+                            throw new ArgumentException("Join specification must define ON predicate.", "specification");
+
+                        return Join(spec.OnPredicate, spec.Alias, spec.JoinType);
+                    }
                     public IDynamicTypedSelectQueryBuilder<T> InnerJoin<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null)
                     {
                         return Join(on, alias, DynamicJoinType.Inner);

DynamORM.Tests/Select/TypedFluentBuilderTests.cs

@@ -100,7 +100,7 @@ namespace DynamORM.Tests.Select
         public void TestTypedJoin()
         {
             var cmd = Database.From<TypedFluentUser>("u")
-                .Join<TypedFluentUser>((l, r) => l.Id == r.Id, "x")
+                .Join<TypedFluentUser>(j => j.As("x").On((l, r) => l.Id == r.Id))
                 .Select(u => u.Id);
 
             Assert.AreEqual("SELECT u.\"id_user\" FROM \"sample_users\" AS u INNER JOIN \"sample_users\" AS x ON (u.\"id_user\" = x.\"id_user\")",
@@ -111,7 +111,7 @@ namespace DynamORM.Tests.Select
         public void TestTypedLeftJoin()
         {
             var cmd = Database.From<TypedFluentUser>("u")
-                .LeftJoin<TypedFluentUser>((l, r) => l.Id == r.Id, "x")
+                .Join<TypedFluentUser>(j => j.Left().As("x").On((l, r) => l.Id == r.Id))
                 .Select(u => u.Id);
 
             Assert.AreEqual("SELECT u.\"id_user\" FROM \"sample_users\" AS u LEFT JOIN \"sample_users\" AS x ON (u.\"id_user\" = x.\"id_user\")",

DynamORM/Builders/IDynamicTypedSelectQueryBuilder.cs

@@ -43,6 +43,12 @@ namespace DynamORM.Builders
         /// <returns>Builder instance.</returns>
         IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null, DynamicJoinType joinType = DynamicJoinType.Inner);
 
+        /// <summary>Add typed join using join-spec builder syntax (<c>As()</c>, join kind and <c>On()</c>).</summary>
+        /// <typeparam name="TRight">Joined mapped entity type.</typeparam>
+        /// <param name="specification">Join specification builder callback.</param>
+        /// <returns>Builder instance.</returns>
+        IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Func<TypedJoinBuilder<T, TRight>, TypedJoinBuilder<T, TRight>> specification);
+
         /// <summary>Add INNER JOIN using typed ON predicate.</summary>
         IDynamicTypedSelectQueryBuilder<T> InnerJoin<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null);
 

DynamORM/Builders/Implementation/DynamicTypedSelectQueryBuilder.cs

@@ -104,6 +104,20 @@ namespace DynamORM.Builders.Implementation
             return this;
         }
 
+        public IDynamicTypedSelectQueryBuilder<T> Join<TRight>(Func<TypedJoinBuilder<T, TRight>, TypedJoinBuilder<T, TRight>> specification)
+        {
+            if (specification == null)
+                throw new ArgumentNullException("specification");
+
+            TypedJoinBuilder<T, TRight> spec = specification(new TypedJoinBuilder<T, TRight>());
+            if (spec == null)
+                throw new ArgumentException("Join specification cannot resolve to null.", "specification");
+            if (spec.OnPredicate == null)
+                throw new ArgumentException("Join specification must define ON predicate.", "specification");
+
+            return Join(spec.OnPredicate, spec.Alias, spec.JoinType);
+        }
+
         public IDynamicTypedSelectQueryBuilder<T> InnerJoin<TRight>(Expression<Func<T, TRight, bool>> on, string alias = null)
         {
             return Join(on, alias, DynamicJoinType.Inner);

DynamORM/Builders/TypedJoinBuilder.cs

@@ -0,0 +1,76 @@
+/*
+ * DynamORM - Dynamic Object-Relational Mapping library.
+ * Copyright (c) 2012-2026, Grzegorz Russek (grzegorz.russek@gmail.com)
+ * All rights reserved.
+ */
+
+using System;
+using System.Linq.Expressions;
+
+namespace DynamORM.Builders
+{
+    /// <summary>Typed join specification builder used by typed fluent select queries.</summary>
+    /// <typeparam name="TLeft">Left side mapped type.</typeparam>
+    /// <typeparam name="TRight">Right side mapped type.</typeparam>
+    public class TypedJoinBuilder<TLeft, TRight>
+    {
+        internal TypedJoinBuilder()
+        {
+            JoinType = DynamicJoinType.Inner;
+        }
+
+        /// <summary>Gets join alias.</summary>
+        public string Alias { get; private set; }
+
+        /// <summary>Gets join type.</summary>
+        public DynamicJoinType JoinType { get; private set; }
+
+        /// <summary>Gets ON predicate.</summary>
+        public Expression<Func<TLeft, TRight, bool>> OnPredicate { get; private set; }
+
+        /// <summary>Sets join alias.</summary>
+        public TypedJoinBuilder<TLeft, TRight> As(string alias)
+        {
+            Alias = alias;
+            return this;
+        }
+
+        /// <summary>Sets INNER JOIN.</summary>
+        public TypedJoinBuilder<TLeft, TRight> Inner()
+        {
+            JoinType = DynamicJoinType.Inner;
+            return this;
+        }
+
+        /// <summary>Sets LEFT JOIN.</summary>
+        public TypedJoinBuilder<TLeft, TRight> Left()
+        {
+            JoinType = DynamicJoinType.Left;
+            return this;
+        }
+
+        /// <summary>Sets RIGHT JOIN.</summary>
+        public TypedJoinBuilder<TLeft, TRight> Right()
+        {
+            JoinType = DynamicJoinType.Right;
+            return this;
+        }
+
+        /// <summary>Sets FULL JOIN.</summary>
+        public TypedJoinBuilder<TLeft, TRight> Full()
+        {
+            JoinType = DynamicJoinType.Full;
+            return this;
+        }
+
+        /// <summary>Sets ON predicate.</summary>
+        public TypedJoinBuilder<TLeft, TRight> On(Expression<Func<TLeft, TRight, bool>> predicate)
+        {
+            if (predicate == null)
+                throw new ArgumentNullException("predicate");
+
+            OnPredicate = predicate;
+            return this;
+        }
+    }
+}