From a13a9858fb13828bab5815d2d02f8f9f69855a1a Mon Sep 17 00:00:00 2001
From: Andrew Golovashevich <landgrafhomyak@gmail.com>
Date: Sat, 15 Feb 2025 23:19:34 +0300
Subject: [PATCH] Support for SQL 'UNION' operation

---
 .../db/serdha0/api/queries/SelectQuery.kt     | 23 +++++++++++++++++++
 .../db/serdha0/api/queries/_Query.kt          |  1 +
 2 files changed, 24 insertions(+)

diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/SelectQuery.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/SelectQuery.kt
index 2ce9d47..2b3c03d 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/SelectQuery.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/SelectQuery.kt
@@ -147,4 +147,27 @@ public interface SelectQuery<out qUE : Any> : _Query<qUE> {
 			}
 		}
 	}
+
+
+	public interface Union<out qUE : Any> : SelectQuery<qUE>, _Query.Params2Table<qUE> {
+		public interface Constructor<qUE : Any, fqUE : Any, lqUE : Any> : _Query.Constructor<Union<qUE>> {
+			override fun createQuery(internalQueries: _Query.Constructor.Scope, outQueries: _Query.Constructor.Scope): Union<qUE> =
+				outQueries.selectUnion(this)
+
+			public val first: _Selectable<fqUE>
+			public val last: _Selectable<lqUE>
+
+			public fun createSelectWithJoin(context: Scope<qUE, fqUE, lqUE>): qUE
+
+			public interface Scope<qUE : Any, fqUE : Any, lqUE : Any> : _CommonSelectCreatorScope<qUE> {
+				public val fq: _Selectable<fqUE>
+				public val lq: _Selectable<lqUE>
+
+				public val firstSubqueryParams: InputRow.WithRedirect<fqUE, qUE>
+				public val lastSubqueryParams: InputRow.WithRedirect<lqUE, qUE>
+
+				public fun <RT, DT : DatabaseType<RT>> uniteColumns(first: Column<RT, DT, fqUE>, last: Column<RT, DT, lqUE>): IntermediateColumn<RT, DT, qUE>
+			}
+		}
+	}
 }
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/_Query.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/_Query.kt
index ca8a58f..2264aa5 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/_Query.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/queries/_Query.kt
@@ -22,6 +22,7 @@ public interface _Query<out qUE : Any> {
 			public fun <qUE : Any, lUE : Any, rUE : Any> selectWithJoin(constructor: SelectQuery.WithJoin.Constructor<qUE, lUE, rUE>): SelectQuery.WithJoin<qUE>
 			public fun <qUE : Any, sqUE : Any> selectReducing(constructor: SelectQuery.Reducing.Constructor<qUE, sqUE>): SelectQuery.Reducing<qUE>
 			public fun <qUE : Any, sqUE : Any> selectFolding(constructor: SelectQuery.Folding.Constructor<qUE, sqUE>): SelectQuery.Folding<qUE>
+			public fun <qUE : Any, fqUE : Any, lqUE : Any> selectUnion(constructor: SelectQuery.Union.Constructor<qUE, fqUE, lqUE>): SelectQuery.Union<qUE>
 		}
 
 		public interface Scope : _SelectsScope {