diff --git a/row_type.go b/row_type.go
deleted file mode 100644
index 2777373..0000000
--- a/row_type.go
+++ /dev/null
@@ -1,6 +0,0 @@
-package jet
-
-type rowsType interface {
-	clause
-	projections() []projection
-}
diff --git a/select_statement.go b/select_statement.go
index 2a6670b..2174a7b 100644
--- a/select_statement.go
+++ b/select_statement.go
@@ -28,6 +28,13 @@ type SelectStatement interface {
 	OFFSET(offset int64) SelectStatement
 	FOR(lock SelectLock) SelectStatement
 
+	UNION(rhs SelectStatement) SelectStatement
+	UNION_ALL(rhs SelectStatement) SelectStatement
+	INTERSECT(rhs SelectStatement) SelectStatement
+	INTERSECT_ALL(rhs SelectStatement) SelectStatement
+	EXCEPT(rhs SelectStatement) SelectStatement
+	EXCEPT_ALL(rhs SelectStatement) SelectStatement
+
 	AsTable(alias string) ExpressionTable
 
 	projections() []projection
@@ -39,6 +46,7 @@ func SELECT(projection1 projection, projections ...projection) SelectStatement {
 
 type selectStatementImpl struct {
 	expressionInterfaceImpl
+	parent SelectStatement
 
 	table          ReadableTable
 	distinct       bool
@@ -46,8 +54,8 @@ type selectStatementImpl struct {
 	where          BoolExpression
 	groupBy        []groupByClause
 	having         BoolExpression
-	orderBy        []OrderByClause
 
+	orderBy       []OrderByClause
 	limit, offset int64
 
 	lockFor SelectLock
@@ -63,13 +71,86 @@ func newSelectStatement(table ReadableTable, projections []projection) SelectSta
 	}
 
 	newSelect.expressionInterfaceImpl.parent = newSelect
+	newSelect.parent = newSelect
 
 	return newSelect
 }
 
 func (s *selectStatementImpl) FROM(table ReadableTable) SelectStatement {
 	s.table = table
-	return s
+	return s.parent
+}
+
+func (s *selectStatementImpl) AsTable(alias string) ExpressionTable {
+	return newExpressionTable(s.parent, alias, s.parent.projections())
+}
+
+func (s *selectStatementImpl) WHERE(expression BoolExpression) SelectStatement {
+	s.where = expression
+	return s.parent
+}
+
+func (s *selectStatementImpl) GROUP_BY(groupByClauses ...groupByClause) SelectStatement {
+	s.groupBy = groupByClauses
+	return s.parent
+}
+
+func (s *selectStatementImpl) HAVING(expression BoolExpression) SelectStatement {
+	s.having = expression
+	return s.parent
+}
+
+func (s *selectStatementImpl) ORDER_BY(clauses ...OrderByClause) SelectStatement {
+	s.orderBy = clauses
+	return s.parent
+}
+
+func (s *selectStatementImpl) OFFSET(offset int64) SelectStatement {
+	s.offset = offset
+	return s.parent
+}
+
+func (s *selectStatementImpl) LIMIT(limit int64) SelectStatement {
+	s.limit = limit
+	return s.parent
+}
+
+func (s *selectStatementImpl) DISTINCT() SelectStatement {
+	s.distinct = true
+	return s.parent
+}
+
+func (s *selectStatementImpl) FOR(lock SelectLock) SelectStatement {
+	s.lockFor = lock
+	return s.parent
+}
+
+func (s *selectStatementImpl) UNION(rhs SelectStatement) SelectStatement {
+	return UNION(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) UNION_ALL(rhs SelectStatement) SelectStatement {
+	return UNION_ALL(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) INTERSECT(rhs SelectStatement) SelectStatement {
+	return INTERSECT(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) INTERSECT_ALL(rhs SelectStatement) SelectStatement {
+	return INTERSECT_ALL(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) EXCEPT(rhs SelectStatement) SelectStatement {
+	return EXCEPT(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) EXCEPT_ALL(rhs SelectStatement) SelectStatement {
+	return EXCEPT_ALL(s.parent, rhs)
+}
+
+func (s *selectStatementImpl) projections() []projection {
+	return s.projectionList
 }
 
 func (s *selectStatementImpl) serialize(statement statementType, out *queryData, options ...serializeOption) error {
@@ -192,56 +273,26 @@ func (s *selectStatementImpl) Sql() (query string, args []interface{}, err error
 }
 
 func (s *selectStatementImpl) DebugSql() (query string, err error) {
-	return debugSql(s)
+	return debugSql(s.parent)
 }
 
-func (s *selectStatementImpl) projections() []projection {
-	return s.projectionList
+func (s *selectStatementImpl) Query(db execution.DB, destination interface{}) error {
+	return query(s.parent, db, destination)
 }
 
-func (s *selectStatementImpl) AsTable(alias string) ExpressionTable {
-	return newExpressionTable(s.parent, alias, s.projectionList)
+func (s *selectStatementImpl) QueryContext(db execution.DB, context context.Context, destination interface{}) error {
+	return queryContext(s.parent, db, context, destination)
 }
 
-func (s *selectStatementImpl) WHERE(expression BoolExpression) SelectStatement {
-	s.where = expression
-	return s
+func (s *selectStatementImpl) Exec(db execution.DB) (res sql.Result, err error) {
+	return exec(s.parent, db)
 }
 
-func (s *selectStatementImpl) GROUP_BY(groupByClauses ...groupByClause) SelectStatement {
-	s.groupBy = groupByClauses
-	return s
+func (s *selectStatementImpl) ExecContext(db execution.DB, context context.Context) (res sql.Result, err error) {
+	return execContext(s.parent, db, context)
 }
 
-func (s *selectStatementImpl) HAVING(expression BoolExpression) SelectStatement {
-	s.having = expression
-	return s
-}
-
-func (s *selectStatementImpl) ORDER_BY(clauses ...OrderByClause) SelectStatement {
-	s.orderBy = clauses
-	return s
-}
-
-func (s *selectStatementImpl) OFFSET(offset int64) SelectStatement {
-	s.offset = offset
-	return s
-}
-
-func (s *selectStatementImpl) LIMIT(limit int64) SelectStatement {
-	s.limit = limit
-	return s
-}
-
-func (s *selectStatementImpl) DISTINCT() SelectStatement {
-	s.distinct = true
-	return s
-}
-
-func (s *selectStatementImpl) FOR(lock SelectLock) SelectStatement {
-	s.lockFor = lock
-	return s
-}
+// SelectLock
 
 type SelectLock interface {
 	clause
@@ -288,19 +339,3 @@ func (s *selectLockImpl) serialize(statement statementType, out *queryData, opti
 
 	return nil
 }
-
-func (s *selectStatementImpl) Query(db execution.DB, destination interface{}) error {
-	return query(s, db, destination)
-}
-
-func (s *selectStatementImpl) QueryContext(db execution.DB, context context.Context, destination interface{}) error {
-	return queryContext(s, db, context, destination)
-}
-
-func (s *selectStatementImpl) Exec(db execution.DB) (res sql.Result, err error) {
-	return exec(s, db)
-}
-
-func (s *selectStatementImpl) ExecContext(db execution.DB, context context.Context) (res sql.Result, err error) {
-	return execContext(s, db, context)
-}
diff --git a/set_statement.go b/set_statement.go
index 8efca36..e28f0ec 100644
--- a/set_statement.go
+++ b/set_statement.go
@@ -1,23 +1,35 @@
 package jet
 
 import (
-	"context"
-	"database/sql"
 	"errors"
-	"github.com/go-jet/jet/execution"
 )
 
-type SetStatement interface {
-	Statement
-	Expression
+func UNION(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(union, false, toSelectList(lhs, rhs, selects...))
+}
 
-	ORDER_BY(clauses ...OrderByClause) SetStatement
-	LIMIT(limit int64) SetStatement
-	OFFSET(offset int64) SetStatement
+func UNION_ALL(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(union, true, toSelectList(lhs, rhs, selects...))
+}
 
-	AsTable(alias string) ExpressionTable
+func INTERSECT(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(intersect, false, toSelectList(lhs, rhs, selects...))
+}
 
-	projections() []projection
+func INTERSECT_ALL(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(intersect, true, toSelectList(lhs, rhs, selects...))
+}
+
+func EXCEPT(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(except, false, toSelectList(lhs, rhs, selects...))
+}
+
+func EXCEPT_ALL(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement {
+	return newSetStatementImpl(except, true, toSelectList(lhs, rhs, selects...))
+}
+
+func toSelectList(lhs, rhs SelectStatement, selects ...SelectStatement) []SelectStatement {
+	return append([]SelectStatement{lhs, rhs}, selects...)
 }
 
 const (
@@ -26,71 +38,30 @@ const (
 	except    = "EXCEPT"
 )
 
-func UNION(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(union, false, selects...)
-}
-
-func UNION_ALL(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(union, true, selects...)
-}
-
-func INTERSECT(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(intersect, false, selects...)
-}
-
-func INTERSECT_ALL(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(intersect, true, selects...)
-}
-
-func EXCEPT(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(except, false, selects...)
-}
-
-func EXCEPT_ALL(selects ...rowsType) SetStatement {
-	return newSetStatementImpl(except, true, selects...)
-}
-
 // Similar to selectStatementImpl, but less complete
 type setStatementImpl struct {
-	expressionInterfaceImpl
+	selectStatementImpl
 
-	operator      string
-	selects       []rowsType
-	orderBy       []OrderByClause
-	limit, offset int64
-
-	all bool
+	operator string
+	all      bool
+	selects  []SelectStatement
 }
 
-func newSetStatementImpl(operator string, all bool, selects ...rowsType) SetStatement {
+func newSetStatementImpl(operator string, all bool, selects []SelectStatement) SelectStatement {
 	setStatement := &setStatementImpl{
 		operator: operator,
-		selects:  selects,
-		limit:    -1,
-		offset:   -1,
 		all:      all,
+		selects:  selects,
 	}
 
-	setStatement.expressionInterfaceImpl.parent = setStatement
+	setStatement.selectStatementImpl.expressionInterfaceImpl.parent = setStatement
+	setStatement.selectStatementImpl.parent = setStatement
+	setStatement.limit = -1
+	setStatement.offset = -1
 
 	return setStatement
 }
 
-func (s *setStatementImpl) ORDER_BY(orderBy ...OrderByClause) SetStatement {
-	s.orderBy = orderBy
-	return s
-}
-
-func (s *setStatementImpl) LIMIT(limit int64) SetStatement {
-	s.limit = limit
-	return s
-}
-
-func (s *setStatementImpl) OFFSET(offset int64) SetStatement {
-	s.offset = offset
-	return s
-}
-
 func (s *setStatementImpl) projections() []projection {
 	if len(s.selects) > 0 {
 		return s.selects[0].projections()
@@ -98,10 +69,6 @@ func (s *setStatementImpl) projections() []projection {
 	return []projection{}
 }
 
-func (s *setStatementImpl) AsTable(alias string) ExpressionTable {
-	return newExpressionTable(s.parent, alias, s.projections())
-}
-
 func (s *setStatementImpl) serialize(statement statementType, out *queryData, options ...serializeOption) error {
 	if s == nil {
 		return errors.New("Set expression is nil. ")
@@ -153,6 +120,10 @@ func (s *setStatementImpl) serializeImpl(out *queryData) error {
 			out.newLine()
 		}
 
+		if selectStmt == nil {
+			return errors.New("select statement is nil")
+		}
+
 		err := selectStmt.serialize(set_statement, out)
 
 		if err != nil {
@@ -198,23 +169,3 @@ func (s *setStatementImpl) Sql() (query string, args []interface{}, err error) {
 	query, args = queryData.finalize()
 	return
 }
-
-func (s *setStatementImpl) DebugSql() (query string, err error) {
-	return debugSql(s)
-}
-
-func (s *setStatementImpl) Query(db execution.DB, destination interface{}) error {
-	return query(s, db, destination)
-}
-
-func (s *setStatementImpl) QueryContext(db execution.DB, context context.Context, destination interface{}) error {
-	return queryContext(s, db, context, destination)
-}
-
-func (s *setStatementImpl) Exec(db execution.DB) (res sql.Result, err error) {
-	return exec(s, db)
-}
-
-func (s *setStatementImpl) ExecContext(db execution.DB, context context.Context) (res sql.Result, err error) {
-	return execContext(s, db, context)
-}
diff --git a/set_statement_test.go b/set_statement_test.go
index 87b57bb..9741c14 100644
--- a/set_statement_test.go
+++ b/set_statement_test.go
@@ -1,34 +1,13 @@
 package jet
 
 import (
+	"fmt"
 	"gotest.tools/assert"
 	"testing"
 )
 
-func TestUnionNoSelect(t *testing.T) {
-	_, _, err := UNION().Sql()
-
-	assert.Assert(t, err != nil)
-	//fmt.Println(err.Error())
-	//fmt.Print(query, args)
-}
-
-func TestUnionOneSelect(t *testing.T) {
-	_, _, err := UNION(
-		table1.SELECT(table1Col1),
-	).Sql()
-
-	assert.Assert(t, err != nil)
-}
-
 func TestUnionTwoSelect(t *testing.T) {
-	query, args, err := UNION(
-		table1.SELECT(table1Col1),
-		table2.SELECT(table2Col3),
-	).Sql()
-
-	assert.NilError(t, err)
-	assert.Equal(t, query, `
+	var expectedSql = `
 (
      (
           SELECT table1.col1 AS "table1.col1"
@@ -40,19 +19,71 @@ func TestUnionTwoSelect(t *testing.T) {
           FROM db.table2
      )
 );
-`)
-	assert.Equal(t, len(args), 0)
+`
+	unionStmt1 := table1.
+		SELECT(table1Col1).
+		UNION(
+			table2.SELECT(table2Col3),
+		)
+
+	unionStmt2 := UNION(table1.SELECT(table1Col1), table2.SELECT(table2Col3))
+
+	assertStatement(t, unionStmt1, expectedSql)
+	assertStatement(t, unionStmt2, expectedSql)
 }
 
-func TestUnionThreeSelect(t *testing.T) {
-	query, args, err := UNION(
+func TestUnionNilSelect(t *testing.T) {
+	unionStmt := table1.
+		SELECT(table1Col1).
+		UNION(nil)
+
+	assertStatementErr(t, unionStmt, "select statement is nil")
+}
+
+func TestUnionThreeSelect1(t *testing.T) {
+
+	unionStmt1 := table1.SELECT(table1Col1).
+		UNION(
+			table2.SELECT(table2Col3),
+		).
+		UNION(
+			table3.SELECT(table3Col1),
+		)
+
+	var expectedSql = `
+(
+     
+     (
+          (
+               SELECT table1.col1 AS "table1.col1"
+               FROM db.table1
+          )
+          UNION
+          (
+               SELECT table2.col3 AS "table2.col3"
+               FROM db.table2
+          )
+     )
+     UNION
+     (
+          SELECT table3.col1 AS "table3.col1"
+          FROM db.table3
+     )
+);
+`
+
+	assertStatement(t, unionStmt1, expectedSql)
+}
+
+func TestUnionThreeSelect2(t *testing.T) {
+
+	unionStmt2 := UNION(
 		table1.SELECT(table1Col1),
 		table2.SELECT(table2Col3),
 		table3.SELECT(table3Col1),
-	).Sql()
+	)
 
-	assert.NilError(t, err)
-	assert.Equal(t, query, `
+	var expectedSql = `
 (
      (
           SELECT table1.col1 AS "table1.col1"
@@ -69,18 +100,19 @@ func TestUnionThreeSelect(t *testing.T) {
           FROM db.table3
      )
 );
-`)
-	assert.Equal(t, len(args), 0)
+`
+
+	assertStatement(t, unionStmt2, expectedSql)
 }
 
 func TestUnionWithOrderBy(t *testing.T) {
-	query, args, err := UNION(
+	unionStmt := UNION(
 		table1.SELECT(table1Col1),
 		table2.SELECT(table2Col3),
-	).ORDER_BY(table1Col1.ASC()).Sql()
+	).
+		ORDER_BY(table1Col1.ASC())
 
-	assert.NilError(t, err)
-	assert.Equal(t, query, `
+	assertStatement(t, unionStmt, `
 (
      (
           SELECT table1.col1 AS "table1.col1"
@@ -94,14 +126,15 @@ func TestUnionWithOrderBy(t *testing.T) {
 )
 ORDER BY "table1.col1" ASC;
 `)
-	assert.Equal(t, len(args), 0)
 }
 
-func TestUnionWithLimit(t *testing.T) {
+func TestUnionWithLimitAndOffset(t *testing.T) {
 	query, args, err := UNION(
 		table1.SELECT(table1Col1),
 		table2.SELECT(table2Col3),
-	).LIMIT(10).OFFSET(11).Sql()
+	).
+		LIMIT(10).
+		OFFSET(11).Sql()
 
 	assert.NilError(t, err)
 	assert.Equal(t, query, `
@@ -150,11 +183,8 @@ func TestUnionInUnion(t *testing.T) {
 		UNION_ALL(table1.SELECT(table1Col1), table2.SELECT(table2Col3)),
 	)
 
-	queryStr, args, err := query.Sql()
-
-	assert.NilError(t, err)
-	assert.Equal(t, len(args), 0)
-	assert.Equal(t, queryStr, expectedSql)
+	fmt.Println(query.Sql())
+	assertStatement(t, query, expectedSql)
 }
 
 func TestUnionALL(t *testing.T) {
diff --git a/tests/select_test.go b/tests/select_test.go
index 4dfc337..cab7198 100644
--- a/tests/select_test.go
+++ b/tests/select_test.go
@@ -963,6 +963,41 @@ OFFSET 20;
 	})
 }
 
+func TestAllSetOperators(t *testing.T) {
+
+	select1 := Payment.SELECT(Payment.AllColumns).WHERE(Payment.PaymentID.GT_EQ(Int(17600)).AND(Payment.PaymentID.LT(Int(17610))))
+	select2 := Payment.SELECT(Payment.AllColumns).WHERE(Payment.PaymentID.GT_EQ(Int(17620)).AND(Payment.PaymentID.LT(Int(17630))))
+
+	type setOperator func(lhs, rhs SelectStatement, selects ...SelectStatement) SelectStatement
+	operators := []setOperator{
+		UNION,
+		UNION_ALL,
+		INTERSECT,
+		INTERSECT_ALL,
+		EXCEPT,
+		EXCEPT_ALL,
+	}
+
+	expectedDestLen := []int{
+		20,
+		20,
+		0,
+		0,
+		10,
+		10,
+	}
+
+	for i, operator := range operators {
+		query := operator(select1, select2)
+
+		dest := []model.Payment{}
+		err := query.Query(db, &dest)
+
+		assert.NilError(t, err)
+		assert.Equal(t, len(dest), expectedDestLen[i])
+	}
+}
+
 func TestSelectWithCase(t *testing.T) {
 	expectedQuery := `
 SELECT (CASE payment.staff_id WHEN 1 THEN 'ONE' WHEN 2 THEN 'TWO' WHEN 3 THEN 'THREE' ELSE 'OTHER' END) AS "staff_id_num"