#253 Support for table join queries using CTE

mk3008 · Oct 24, 2023 · 3535083 · 3535083
1 parent 55c51b8
commit 3535083
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Showing 4 changed files with 102 additions and 20 deletions.
diff --git a/src/QueryBuilderByLinq/MemberExpressionExtension.cs b/src/QueryBuilderByLinq/MemberExpressionExtension.cs
@@ -42,6 +42,7 @@ internal static ValueBase ToValue(this MemberExpression exp, List<string> tables
 		if (exp.Expression is MemberExpression mem)
 		{
 			var table = tables.Where(x => x == mem.Member.Name).FirstOrDefault();
+			if (mem.Member.Name.StartsWith("<>h__TransparentIdentifier")) table = mem.Member.Name;
 
 			if (!string.IsNullOrEmpty(table))
 			{

diff --git a/src/QueryBuilderByLinq/SelectQueryBuilder.cs b/src/QueryBuilderByLinq/SelectQueryBuilder.cs
@@ -233,33 +233,59 @@ private SelectQuery BuildRootQuery(MethodCallExpression expression, ConstantExpr
 	private SelectQuery BuildNestedQuery(MethodCallExpression expression, SelectQuery sq)
 	{
 		var where = GetWhereExpression(expression);
-
-		if (sq.FromClause == null && (expression.Arguments.Count == 2))
-		{
-			var exp = (MethodCallExpression)expression.Arguments[0];
-			return BuildRootQuery(exp, sq, where);
-		}
-
 		var join = GetJoinExpression(expression);
 		var select = GetSelectExpression(expression);
 		var joinAlias = GetJoinAlias(select, where);
 
-		var tables = sq.GetSelectableTables().Select(x => x.Alias).ToList();
-
-		if (join != null && joinAlias != null)
+		if (sq.FromClause == null)
 		{
-			tables.Add(joinAlias.Name!);
-			sq.AddJoinClause(join, tables, joinAlias);
+			if (expression.Arguments.Count == 2)
+			{
+				var exp = (MethodCallExpression)expression.Arguments[0];
+				sq = BuildRootQuery(exp, sq);
+
+				var ts = sq.GetSelectableTables().Select(x => x.Alias).ToList();
+				if (where != null) sq.Where(where.ToValue(ts));
+				return sq;
+			}
+			if (expression.Arguments.Count == 3 && join != null && joinAlias != null)
+			{
+				var exp = (MethodCallExpression)expression.Arguments[0];
+				sq = BuildRootQuery(exp, sq);
+
+				var ts = sq.GetSelectableTables().Select(x => x.Alias).ToList();
+				ts.Add(joinAlias.Name!);
+				sq.AddJoinClause(join, ts, joinAlias);
+
+				if (where != null) sq.Where(where.ToValue(ts));
+
+				return sq;
+			}
 		}
 
-		if (where != null) sq.Where(where.ToValue(tables));
+		if (sq.FromClause == null) throw new NotSupportedException();
+		{
+			var tables = sq.GetSelectableTables().Select(x => x.Alias).ToList();
 
-		//refresh select clause
-		sq.SelectClause = null;
-		return sq.AddSelectClause(select, where, tables);
+			if (join != null && joinAlias != null)
+			{
+				tables.Add(joinAlias.Name!);
+				sq.AddJoinClause(join, tables, joinAlias);
+			}
+
+			if (where != null) sq.Where(where.ToValue(tables));
+
+			//refresh select clause
+			if (select != null)
+			{
+				sq.SelectClause = null;
+				sq.AddSelectClause(select, where, tables);
+			}
+			return sq;
+		}
 	}
 
-	private SelectQuery BuildRootQuery(MethodCallExpression expression, SelectQuery sq, LambdaExpression? where)
+	private SelectQuery BuildRootQuery(MethodCallExpression expression, SelectQuery sq)
 	{
 		var select = GetSelectExpression(expression);
 
@@ -272,7 +298,7 @@ private SelectQuery BuildRootQuery(MethodCallExpression expression, SelectQuery
 		if (string.IsNullOrEmpty(alias?.Name)) throw new NotSupportedException();
 
 		var tables = new List<string> { alias.Name! };
-		if (where != null) sq.Where(where.ToValue(tables));
+		//if (where != null) sq.Where(where.ToValue(tables));
 
 		var v = (ValueCollection)select.Body.ToValue(tables);
 

diff --git a/src/QueryBuilderByLinq/SelectQueryExtension.cs b/src/QueryBuilderByLinq/SelectQueryExtension.cs
@@ -4,7 +4,6 @@
 using Carbunql.Tables;
 using Carbunql.Values;
 using System.Linq.Expressions;
-using System.Xml.Linq;
 
 namespace QueryBuilderByLinq;
 
@@ -91,6 +90,10 @@ public static SelectQuery AddJoinClause(this SelectQuery sq, LambdaExpression jo
 			return sq;
 		}
 
+		if (sq.FromClause == null)
+		{
+			throw new InvalidProgramException();
+		}
 		var f = sq.FromClause!;
 
 		if (me.Method.Name == nameof(Sql.InnerJoinTable))
@@ -113,7 +116,20 @@ public static SelectQuery AddJoinClause(this SelectQuery sq, LambdaExpression jo
 			}
 			else if (me.GetJoinTableName(out var name))
 			{
-				f.InnerJoin(name).As(joinAlias.Name!).On((_) => condition);
+				var cte = sq.WithClause?.Where(x => x.Alias == name).FirstOrDefault();
+				if (cte != null && !string.IsNullOrEmpty(cte.Alias))
+				{
+					var t = new PhysicalTable()
+					{
+						Table = cte.Alias,
+						ColumnNames = cte.GetColumnNames().ToList()
+					};
+					f.InnerJoin(t.ToSelectable()).As(joinAlias.Name!).On((_) => condition);
+				}
+				else
+				{
+					f.InnerJoin(name).As(joinAlias.Name!).On((_) => condition);
+				}
 			}
 			else
 			{

diff --git a/test/QueryBuilderByLinq.Test/CommonTableTest.cs b/test/QueryBuilderByLinq.Test/CommonTableTest.cs
@@ -51,5 +51,44 @@ cte AS b
 		Assert.Equal(sql.ToValidateText(), sq.ToText().ToValidateText());
 	}
 
+	[Fact]
+	public void RelationTest()
+	{
+		var subq = from a in FromTable<table_a>() select new { ID = a.a_id, Text = a.text };
+
+		var query = from cte in CommonTable(subq)
+					from b in FromTable<table_a>(nameof(cte))
+					from c in InnerJoinTable<table_a>(nameof(cte), x => b.a_id == x.a_id)
+					where b.a_id == 1
+					select new { b, c };
+
+		var sq = query.ToQueryAsPostgres();
+
+		Monitor.Log(sq);
+
+		var sql = @"
+WITH
+    cte AS (
+        SELECT
+            a.a_id AS ID,
+            a.text AS Text
+        FROM
+            table_a AS a
+    )
+SELECT
+    b.ID,
+    b.Text,
+    c.ID,
+    c.Text
+FROM
+    cte AS b
+    INNER JOIN cte AS c ON b.a_id = c.a_id
+WHERE
+    b.a_id = 1";
+
+		Assert.Equal(59, sq.GetTokens().ToList().Count);
+		Assert.Equal(sql.ToValidateText(), sq.ToText().ToValidateText());
+	}
+
 	public record struct table_a(int a_id, string text, int value);
 }