diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/Column.kt b/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/Column.kt
index 6435ef2..c2689e3 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/Column.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/Column.kt
@@ -1,9 +1,9 @@
 package ru.landgrafhomyak.serdha.api.v0.ddl
 
-public interface Column<RuntimeType, DatabaseType : ColumnType<RuntimeType & Any>, TableUserWrapper : Any> /*: Expression<RuntimeType, DatabaseType>*/ {
+public interface Column<RuntimeType, DatabaseType : ColumnType<RuntimeType>, TableUserExtension : Any> {
 	public val name: String
 
 	public val type: DatabaseType
 
-	public val table: Table<TableUserWrapper, *>
+	public val table: Table<TableUserExtension, *>
 }
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/TableCreator.kt b/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/TableCreator.kt
index 6183c48..46f5a63 100644
--- a/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/TableCreator.kt
+++ b/src/commonMain/kotlin/ru/landgrafhomyak/serdha/api/v0/ddl/TableCreator.kt
@@ -3,64 +3,52 @@ package ru.landgrafhomyak.serdha.api.v0.ddl
 import kotlin.jvm.JvmName
 import ru.landgrafhomyak.serdha.api.v0.Expression
 
-public interface TableCreator<TableUserWrapper : Any> {
+public interface TableCreator<TableUserExtension : Any> {
+	public val expressionBuilder: Expression.Builder<TableUserExtension>
+
 	/**
 	 * Offers column of type [D][type] with `NOT NULL` constraint named [name] and runtime type [RuntimeType].
 	 *
 	 * @return Descriptor of offered column for future operations.
 	 */
-	public fun <RuntimeType : Any, DatabaseType : ColumnType<RuntimeType>> column(name: String, type: DatabaseType): Column<RuntimeType, DatabaseType, TableUserWrapper>
+	public fun <RuntimeType : Any, DatabaseType : ColumnType<RuntimeType>> column(name: String, type: DatabaseType): Column<RuntimeType, DatabaseType, TableUserExtension>
 
-	@Suppress("INAPPLICABLE_JVM_NAME")
-	@JvmName("nullableColumn\$notNull")
-	@Deprecated("This column can be not-null", replaceWith = ReplaceWith("this.column"))
-	public fun <RuntimeType : Any, DatabaseType : ColumnType<RuntimeType>> nullableColumn(name: String, type: DatabaseType): Column<RuntimeType?, DatabaseType, TableUserWrapper> =
-		this.nullableColumn<RuntimeType?, DatabaseType>(name, type)
+	public fun index(name: String, vararg columns: Column<*, *, TableUserExtension>): Index<TableUserExtension>
 
-	/**
-	 * Offers column of type [D][type] named [name] and runtime type [R?][RuntimeType].
-	 *
-	 * @return Descriptor of offered column for future operations.
-	 */
-	public fun <RuntimeType, DatabaseType : ColumnType<RuntimeType & Any>> nullableColumn(name: String, type: DatabaseType): Column<RuntimeType?, DatabaseType, TableUserWrapper>
+	public fun unique(name: String, distinctNulls: Boolean, vararg columns: Column<*, *, TableUserExtension>): UniqueConstraint<TableUserExtension>
+	public fun check(name: String, constraint: Expression<Boolean, ColumnType.BOOLEAN, TableUserExtension>): CheckConstraint<TableUserExtension>
 
-	public fun index(name: String, vararg columns: Column<*, *, TableUserWrapper>): Index<TableUserWrapper>
+	public fun rowIdColumn(): Column<RowId<TableUserExtension>, ColumnType<RowId<TableUserExtension>>, TableUserExtension>
 
-	// todo not-null column uniqueness
-	public fun unique(name: String, distinctNulls: Boolean, vararg columns: Column<*, *, TableUserWrapper>): UniqueConstraint<TableUserWrapper>
-	public fun check(name: String, constraint: Expression<Boolean, ColumnType.BOOLEAN, TableUserWrapper>): CheckConstraint<TableUserWrapper>
-
-	public fun rowIdColumn(): Column<RowId<TableUserWrapper>, ColumnType<RowId<TableUserWrapper>>, TableUserWrapper>
-
-	public fun rowIdUniqueConstraint(): UniqueConstraint<TableUserWrapper>
+	public fun rowIdUniqueConstraint(): UniqueConstraint<TableUserExtension>
 
 	public fun <TargetTableUserWrapper : Any, ColumnType1 : ColumnType<*>> foreignKey(
-		fromColumn: Column<*, ColumnType1, TableUserWrapper>,
+		fromColumn: Column<*, ColumnType1, TableUserExtension>,
 		toTable: Table<TargetTableUserWrapper, *>,
 		toColumn: Column<*, ColumnType1, TargetTableUserWrapper>,
 		onUpdate: ForeignKey.OnUpdateAction,
 		onDelete: ForeignKey.OnDeleteAction
-	): ForeignKey<TableUserWrapper, TargetTableUserWrapper>
+	): ForeignKey<TableUserExtension, TargetTableUserWrapper>
 
 	public fun <TargetTableUserWrapper : Any, ColumnType1 : ColumnType<*>, ColumnType2 : ColumnType<*>> foreignKey(
-		fromColumn1: Column<*, ColumnType1, TableUserWrapper>,
-		fromColumn2: Column<*, ColumnType2, TableUserWrapper>,
+		fromColumn1: Column<*, ColumnType1, TableUserExtension>,
+		fromColumn2: Column<*, ColumnType2, TableUserExtension>,
 		toTable: Table<TargetTableUserWrapper, *>,
 		toColumn1: Column<*, ColumnType1, TargetTableUserWrapper>,
 		toColumn2: Column<*, ColumnType2, TargetTableUserWrapper>,
 		onUpdate: ForeignKey.OnUpdateAction,
 		onDelete: ForeignKey.OnDeleteAction
-	): ForeignKey<TableUserWrapper, TargetTableUserWrapper>
+	): ForeignKey<TableUserExtension, TargetTableUserWrapper>
 
 	public fun <TargetTableUserWrapper : Any, ColumnType1 : ColumnType<*>, ColumnType2 : ColumnType<*>, ColumnType3 : ColumnType<*>> foreignKey(
-		fromColumn1: Column<*, ColumnType1, TableUserWrapper>,
-		fromColumn2: Column<*, ColumnType2, TableUserWrapper>,
-		fromColumn3: Column<*, ColumnType3, TableUserWrapper>,
+		fromColumn1: Column<*, ColumnType1, TableUserExtension>,
+		fromColumn2: Column<*, ColumnType2, TableUserExtension>,
+		fromColumn3: Column<*, ColumnType3, TableUserExtension>,
 		toTable: Table<TargetTableUserWrapper, *>,
 		toColumn1: Column<*, ColumnType1, TargetTableUserWrapper>,
 		toColumn2: Column<*, ColumnType2, TargetTableUserWrapper>,
 		toColumn3: Column<*, ColumnType3, TargetTableUserWrapper>,
 		onUpdate: ForeignKey.OnUpdateAction,
 		onDelete: ForeignKey.OnDeleteAction
-	): ForeignKey<TableUserWrapper, TargetTableUserWrapper>
+	): ForeignKey<TableUserExtension, TargetTableUserWrapper>
 }
\ No newline at end of file