diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/RowExpression.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/RowExpression.kt
new file mode 100644
index 0000000..3066441
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/RowExpression.kt
@@ -0,0 +1,40 @@
+package ru.landgrafhomyak.db.serdha0.api.misc
+
+import ru.landgrafhomyak.db.serdha0.api.queries._Query
+import ru.landgrafhomyak.db.serdha0.api.runtime.OutputRow
+import ru.landgrafhomyak.db.serdha0.api.table.RowId
+import ru.landgrafhomyak.db.serdha0.api.table.Table
+
+public interface RowExpression<ttUE : Any, @Suppress("unused") R> {
+	public val targetTable: Table<ttUE, *>
+
+	public interface RowExportsConstructor<rUE : Any, ttUE : Any> {
+		public fun createRowExports(context: Scope<rUE, ttUE>): rUE
+
+		public interface Scope<rUE : Any, ttUE : Any> {
+			public val tt: Table<ttUE, *>
+
+			public fun <RT, DT : DatabaseType<RT>> selectFromTargetTable(column: Column<RT, DT, ttUE>): Column<RT, DT, rUE>
+
+			public fun <rtUE : Any, RT, DT : DatabaseType<RT>> followReference(
+				ref: Column<*, *, rUE>,
+				column: Column<RT, DT, rtUE>
+			): Column<RT, DT, rUE>
+
+			public fun <rtUE : Any, RT : Any, DT : DatabaseType<RT>> followReferenceNullable(
+				ref: Column<RowId<rtUE>, DatabaseType.ROW_ID<rtUE>, rUE>,
+				column: Column<RT, DT, rtUE>
+			): Column<RT?, DatabaseType.Nullable<RT, DT>, rUE>
+		}
+	}
+
+	public interface Constructor<ttUE : Any, rUE : Any, R> {
+		public val rowExports: RowExportsConstructor<rUE, ttUE>
+
+		public fun createRowExpression(internalQueries: _Query.Constructor.Scope, runtimeQueries: _Query.Constructor.Scope): Action<rUE, R>
+	}
+
+	public interface Action<rUE : Any, R> {
+		public suspend fun calculateRow(rowUE: rUE, row: OutputRow<rUE>): R
+	}
+}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CheckConstraint.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CheckConstraint.kt
index b52bbd6..64a0e6a 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CheckConstraint.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CheckConstraint.kt
@@ -1,39 +1,7 @@
 package ru.landgrafhomyak.db.serdha0.api.table
 
-import kotlin.jvm.JvmName
-import ru.landgrafhomyak.db.serdha0.api.misc.Column
-import ru.landgrafhomyak.db.serdha0.api.misc.IntermediateColumn
-import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
-import ru.landgrafhomyak.db.serdha0.api.misc.Mapper
+import ru.landgrafhomyak.db.serdha0.api.misc.RowExpression
 
-public interface CheckConstraint<tUE : Any> {
-	@Suppress("INAPPLICABLE_JVM_NAME")
-	@get:JvmName("name")
+public interface CheckConstraint<ttUE : Any> : RowExpression<ttUE, Boolean> {
 	public val name: String
-
-	@Suppress("INAPPLICABLE_JVM_NAME")
-	@get:JvmName("table")
-	public val table: Table<tUE, *>
-
-	public interface Creator<cUE : Any, ttUE : Any> {
-		public fun createCheckConstraint(scope: Scope<cUE, ttUE>)
-
-		public interface Scope<cUE : Any, ttUE : Any> {
-			public val tt: Table<ttUE, *>
-
-			public var result: IntermediateColumn<Boolean, DatabaseType.BOOLEAN, cUE>
-			public fun <RT, DT : DatabaseType<RT>> selectFromTargetTable(column: Column<RT, DT, ttUE>): IntermediateColumn<RT, DT, cUE>
-
-			public fun <rtUE : Any, RT, DT : DatabaseType<RT>> followReference(
-				ref: IntermediateColumn<*, DatabaseType.ROW_ID<rtUE>, cUE>,
-				column: Column<RT, DT, rtUE>
-			): IntermediateColumn<RT, DT, rtUE>
-
-			public fun <eUE : Any> mapColumns(
-				expression: Mapper<eUE>,
-				input: ru.landgrafhomyak.db.serdha0.api.misc.Expression.Map.InputLinker<eUE, cUE>,
-				output: ru.landgrafhomyak.db.serdha0.api.misc.Expression.Map.OutputLinker<eUE, cUE>
-			)
-		}
-	}
 }
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ColumnDefaultValue.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ColumnDefaultValue.kt
new file mode 100644
index 0000000..a4552ce
--- /dev/null
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ColumnDefaultValue.kt
@@ -0,0 +1,6 @@
+package ru.landgrafhomyak.db.serdha0.api.table
+
+import ru.landgrafhomyak.db.serdha0.api.misc.RowExpression
+
+public interface ColumnDefaultValue<ttUE : Any, R> : RowExpression<ttUE, R> {
+}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/DefaultConstraint.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/DefaultConstraint.kt
deleted file mode 100644
index 55a8cb5..0000000
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/DefaultConstraint.kt
+++ /dev/null
@@ -1,39 +0,0 @@
-package ru.landgrafhomyak.db.serdha0.api.table
-
-import kotlin.jvm.JvmName
-import ru.landgrafhomyak.db.serdha0.api.misc.Column
-import ru.landgrafhomyak.db.serdha0.api.misc.IntermediateColumn
-import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
-import ru.landgrafhomyak.db.serdha0.api.misc.Mapper
-
-public interface DefaultConstraint<tUE : Any> {
-	@Suppress("INAPPLICABLE_JVM_NAME")
-	@get:JvmName("name")
-	public val name: String
-
-	@Suppress("INAPPLICABLE_JVM_NAME")
-	@get:JvmName("table")
-	public val table: Table<tUE, *>
-
-	public interface Creator<cUE : Any, RT, DT : DatabaseType<RT>, ttUE : Any> {
-		public fun createCheckConstraint(scope: Scope<cUE, RT, DT, ttUE>)
-
-		public interface Scope<cUE : Any, rRT, rDT : DatabaseType<rRT>, ttUE : Any> {
-			public val tt: Table<ttUE, *>
-
-			public var result: IntermediateColumn<rRT, rDT, cUE>
-			public fun <RT, DT : DatabaseType<RT>> selectFromTargetTable(column: Column<RT, DT, ttUE>): IntermediateColumn<RT, DT, cUE>
-
-			public fun <rtUE : Any, RT, DT : DatabaseType<RT>> followReference(
-				ref: IntermediateColumn<*, DatabaseType.ROW_ID<rtUE>, cUE>,
-				column: Column<RT, DT, rtUE>
-			): IntermediateColumn<RT, DT, rtUE>
-
-			public fun <eUE : Any> mapColumns(
-				expression: Mapper<eUE>,
-				input: ru.landgrafhomyak.db.serdha0.api.misc.Expression.Map.InputLinker<eUE, cUE>,
-				output: ru.landgrafhomyak.db.serdha0.api.misc.Expression.Map.OutputLinker<eUE, cUE>
-			)
-		}
-	}
-}
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/TableConstructor.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/TableConstructor.kt
index 6c64bbc..1712034 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/TableConstructor.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/TableConstructor.kt
@@ -2,6 +2,7 @@ package ru.landgrafhomyak.db.serdha0.api.table
 
 import ru.landgrafhomyak.db.serdha0.api.misc.Column
 import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
+import ru.landgrafhomyak.db.serdha0.api.misc.RowExpression
 
 
 public interface TableConstructor<TableUserExtension : Any> {
@@ -16,8 +17,8 @@ public interface TableConstructor<TableUserExtension : Any> {
 		public fun index(name: String, vararg columns: Column<*, *, tUE>): Index<tUE>
 
 		public fun uniqueIndex(name: String, distinctNulls: Boolean, vararg columns: Column<*, *, tUE>): UniqueIndex<tUE>
-		public fun <cUE : Any> checkConstraint(name: String, creator: CheckConstraint.Creator<cUE, tUE>, recheckExistingRows: Boolean = false): CheckConstraint<tUE>
-		public fun <cUE : Any, RT : Any, DT : DatabaseType<RT>> defaultValue(c: Column<RT, DT, tUE>, creator: DefaultConstraint.Creator<cUE, RT, DT, tUE>): DefaultConstraint<tUE>
+		public fun checkConstraint(name: String, constructor: RowExpression.Constructor<tUE, *, Boolean>, recheckExistingRows: Boolean = false): CheckConstraint<tUE>
+		public fun <RT : Any> defaultValue(c: Column<RT, *, tUE>, creator: RowExpression.Constructor<tUE, *, RT>): ColumnDefaultValue<tUE, RT>
 
 		@Suppress("PropertyName")
 		public val rowId_column: Column<RowId<tUE>, DatabaseType<RowId<tUE>>, tUE>
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/UpdateTableScope.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/UpdateTableScope.kt
index 7a6f550..1e06851 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/UpdateTableScope.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/UpdateTableScope.kt
@@ -4,7 +4,7 @@ import ru.landgrafhomyak.db.serdha0.api.misc.Column
 import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
 
 
-public interface UpdateTableScope<tnUE : Any, toUE : Any> : CreateTableScope<tnUE> {
+public interface UpdateTableScope<tnUE : Any, toUE : Any> : TableConstructor.Scope<tnUE> {
 	public fun <RT, DT : DatabaseType<RT>> keepColumn(c: Column<RT, DT, toUE>): Column<RT, DT, tnUE>
 	public fun <RT, DT : DatabaseType<RT>> keepColumnUntilUpgraded(c: Column<RT, DT, toUE>): Column<RT, DT, tnUE>
 	public fun <RT, DT : DatabaseType<RT>> renameAndKeepColumn(c: Column<RT, DT, toUE>, newName: String): Column<RT, DT, tnUE>
@@ -22,9 +22,9 @@ public interface UpdateTableScope<tnUE : Any, toUE : Any> : CreateTableScope<tnU
 	public fun renameAndKeepUniqueIndex(i: UniqueIndex<toUE>, newName: String): UniqueIndex<tnUE>
 	public fun deleteUniqueIndex(i: UniqueIndex<toUE>)
 
-	public fun <RT, DT : DatabaseType<RT>> keepDefaultValue(c: Column<RT, DT, tnUE>, d: DefaultConstraint<toUE>): DefaultConstraint<tnUE>
-	public fun <RT, DT : DatabaseType<RT>> changeDefaultValue(c: Column<RT, DT, tnUE>, d: DefaultConstraint<toUE>): DefaultConstraint<tnUE>
-	public fun deleteDefaultValue(i: DefaultConstraint<toUE>)
+	public fun <RT, DT : DatabaseType<RT>> keepDefaultValue(c: Column<RT, DT, tnUE>, d: ColumnDefaultValue<toUE, RT>): ColumnDefaultValue<tnUE, RT>
+	public fun <RT, DT : DatabaseType<RT>> changeDefaultValue(c: Column<RT, DT, tnUE>, d: ColumnDefaultValue<toUE, RT>): ColumnDefaultValue<tnUE, RT>
+	public fun deleteDefaultValue(i: ColumnDefaultValue<toUE, *>)
 
 	public fun <ttUE : Any, RT, DT : DatabaseType<RT>> keepForeignRowReference(
 		frr: ForeignRowReference<toUE, ttUE, RT, DT>,