diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/DatabaseType.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/DatabaseType.kt
index d2d28cf..e67b160 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/DatabaseType.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/misc/DatabaseType.kt
@@ -8,10 +8,10 @@ import ru.landgrafhomyak.db.serdha0.api.table.Table
 /**
  * Descriptor of a database type.
  *
- * @param RuntimeType Type in programming language to which database type is converted.
+ * @param RT Type in programming language to which database type is converted.
  */
 @Suppress("ClassName", "RemoveRedundantQualifierName")
-public interface DatabaseType<@Suppress("unused") RuntimeType> {
+public interface DatabaseType<@Suppress("unused") RT> {
 	@Suppress("INAPPLICABLE_JVM_NAME")
 	@get:JvmName("name")
 	public val name: String
@@ -35,7 +35,7 @@ public interface DatabaseType<@Suppress("unused") RuntimeType> {
 
 	public interface Nullable<RT : Any, @Suppress("unused") DT : DatabaseType<RT>> : DatabaseType<RT?>
 
-	public interface ROW_ID<TargetTableUserWrapper : Any> : DatabaseType<RowId<TargetTableUserWrapper>>
+	public interface ROW_ID<ttUE : Any> : DatabaseType<RowId<ttUE>>
 
 	public interface BOOLEAN : DatabaseType<Boolean>
 
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CreateTableScope.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CreateTableScope.kt
index 38c5f02..4889fb4 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CreateTableScope.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/CreateTableScope.kt
@@ -20,13 +20,23 @@ public interface CreateTableScope<tUE : Any> {
 	@Suppress("PropertyName")
 	public val rowId_uniqueConstraint: UniqueIndex<tUE>
 
-	public fun <TargetTableUserWrapper : Any> selfRowReference(
-		onDelete: ForeignRowReference.OnDeleteAction,
-	): ForeignRowReference<tUE, tUE>
+	public fun <ttUE : Any> selfRowReference(
+		onDelete: ForeignRowReference.OnDelete,
+	): ForeignRowReference<tUE, tUE, RowId<tUE>, DatabaseType.ROW_ID<tUE>>
 
-	public fun <TargetTableUserWrapper : Any> foreignRowReference(
+	public fun <ttUE : Any> nullableSelfRowReference(
+		onDelete: ForeignRowReference.OnDelete,
+	): ForeignRowReference<tUE, tUE, RowId<tUE>?, DatabaseType.Nullable<RowId<tUE>, DatabaseType.ROW_ID<tUE>>>
+
+	public fun <ttUE : Any> foreignRowReference(
 		columnName: String,
-		toTable: Table<TargetTableUserWrapper, *>,
-		onDelete: ForeignRowReference.OnDeleteAction,
-	): ForeignRowReference<tUE, TargetTableUserWrapper>
+		toTable: Table<ttUE, *>,
+		onDelete: ForeignRowReference.OnDelete,
+	): ForeignRowReference<tUE, ttUE, RowId<ttUE>, DatabaseType.ROW_ID<ttUE>>
+
+	public fun <ttUE : Any> nullableForeignRowReference(
+		columnName: String,
+		toTable: Table<ttUE, *>,
+		onDelete: ForeignRowReference.OnDelete,
+	): ForeignRowReference<tUE, ttUE, RowId<ttUE>?, DatabaseType.Nullable<RowId<ttUE>, DatabaseType.ROW_ID<ttUE>>>
 }
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ForeignRowReference.kt b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ForeignRowReference.kt
index 9a3a0d9..3f60e9a 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ForeignRowReference.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/db/serdha0/api/table/ForeignRowReference.kt
@@ -10,7 +10,7 @@ import ru.landgrafhomyak.db.serdha0.api.misc.DatabaseType
  * @param ctUE Type of [owner table's][ForeignRowReference.fromTable] user expression for static reporting errors when this descriptor passed to wrong table.
  * @param ttUE Type of [target table's][ForeignRowReference.toTable] user expression for static reporting errors when this descriptor passed to wrong table.
  */
-public interface ForeignRowReference<ctUE : Any, ttUE : Any> : Column<RowId<ttUE>, DatabaseType.ROW_ID<ttUE>, ctUE> {
+public interface ForeignRowReference<ctUE : Any, ttUE : Any, RT : RowId<ttUE>?, DT : DatabaseType<RT>> : Column<RowId<ttUE>, DatabaseType.ROW_ID<ttUE>, ctUE> {
 	/**
 	 * Table that contains references. For debugging.
 	 */
@@ -29,7 +29,7 @@ public interface ForeignRowReference<ctUE : Any, ttUE : Any> : Column<RowId<ttUE
 	/**
 	 * Enum of actions to do when referenced row in [ForeignRowReference.toTable] deleted.
 	 */
-	public enum class OnDeleteAction {
+	public enum class OnDelete {
 		/**
 		 * Forbids deleting row in [ForeignRowReference.toTable] if there is at least one reference from [ForeignRowReference.fromTable].
 		 */
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 e7caa4b..b1c7452 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
@@ -26,38 +26,56 @@ public interface UpdateTableScope<tnUE : Any, toUE : Any> : CreateTableScope<tnU
 	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 <ttUE : Any> keepForeignRowReference(
-		frr: ForeignRowReference<toUE, ttUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttUE>
+	public fun <ttUE : Any, RT : RowId<ttUE>?, DT : DatabaseType<RT>> keepForeignRowReference(
+		frr: ForeignRowReference<toUE, ttUE, RT, DT>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<toUE, ttUE, RT, DT>
 
 	public fun <ttoUE : Any, ttnUE : Any> keepForeignRowReferenceToUpdatedTable(
-		frr: ForeignRowReference<toUE, ttoUE>,
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>,
 		updatedTable: Table<ttnUE, ttoUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttnUE>
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>
 
-	public fun <ttUE : Any> renameAndKeepForeignRowReference(
-		frr: ForeignRowReference<toUE, ttUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttUE>
+	public fun <ttoUE : Any, ttnUE : Any> keepNullableForeignRowReferenceToUpdatedTable(
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>?, DatabaseType.Nullable<RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>>,
+		updatedTable: Table<ttnUE, ttoUE>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>
+
+	public fun <ttUE : Any, RT : RowId<ttUE>?, DT : DatabaseType<RT>> renameAndKeepForeignRowReference(
+		frr: ForeignRowReference<toUE, ttUE, RT, DT>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttUE, RT, DT>
 
 	public fun <ttoUE : Any, ttnUE : Any> renameAndKeepForeignRowReferenceToUpdatedTable(
-		frr: ForeignRowReference<toUE, ttoUE>,
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>,
 		updatedTable: Table<ttnUE, ttoUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttnUE>
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>
 
-	public fun deleteForeignRowReference(frr: ForeignRowReference<toUE, *>)
+	public fun <ttoUE : Any, ttnUE : Any> renameAndKeepNullableForeignRowReferenceToUpdatedTable(
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>?, DatabaseType.Nullable<RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>>,
+		updatedTable: Table<ttnUE, ttoUE>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>?, DatabaseType.Nullable<RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>>
 
-	public fun <ttUE : Any> keepForeignRowReferenceUntilUpgraded(
-		frr: ForeignRowReference<toUE, ttUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttUE>
+	public fun deleteForeignRowReference(frr: ForeignRowReference<toUE, *, *, *>)
+
+	public fun <ttUE : Any, RT : RowId<ttUE>?, DT : DatabaseType<RT>> keepForeignRowReferenceUntilUpgraded(
+		frr: ForeignRowReference<toUE, ttUE, RT, DT>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttUE, RT, DT>
 
 	public fun <ttoUE : Any, ttnUE : Any> keepForeignRowReferenceToUpdatedTableUntilUpgraded(
-		frr: ForeignRowReference<toUE, ttoUE>,
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>,
 		updatedTable: Table<ttnUE, ttoUE>,
-		onDelete: ForeignRowReference.OnDeleteAction? = null
-	): ForeignRowReference<tnUE, ttnUE>
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>
+
+	public fun <ttoUE : Any, ttnUE : Any> keepNullableForeignRowReferenceToUpdatedTableUntilUpgraded(
+		frr: ForeignRowReference<toUE, ttoUE, RowId<ttoUE>?, DatabaseType.Nullable<RowId<ttoUE>, DatabaseType.ROW_ID<ttoUE>>>,
+		updatedTable: Table<ttnUE, ttoUE>,
+		onDelete: ForeignRowReference.OnDelete? = null
+	): ForeignRowReference<tnUE, ttnUE, RowId<ttnUE>?, DatabaseType.Nullable<RowId<ttnUE>, DatabaseType.ROW_ID<ttnUE>>>
 }
\ No newline at end of file