diff --git a/internal/jet/clause.go b/internal/jet/clause.go
index 90d194e..349c6dc 100644
--- a/internal/jet/clause.go
+++ b/internal/jet/clause.go
@@ -518,7 +518,7 @@ type SetPair struct {
 }
 
 // SetClause clause
-type SetClause []SetPair
+type SetClause []ColumnAssigment
 
 // Serialize for SetClause
 func (s SetClause) Serialize(statementType StatementType, out *SQLBuilder, options ...SerializeOption) {
@@ -526,16 +526,15 @@ func (s SetClause) Serialize(statementType StatementType, out *SQLBuilder, optio
 	out.WriteString("SET")
 	out.IncreaseIdent(4)
 
-	for i, pair := range s {
+	for i, assigment := range s {
 		if i > 0 {
 			out.WriteString(",")
 			out.NewLine()
 		}
 
-		pair.Column.serialize(statementType, out, ShortName.WithFallTrough(options)...)
-		out.WriteString("=")
-		pair.Value.serialize(statementType, out, FallTrough(options)...)
+		assigment.serialize(statementType, out, FallTrough(options)...)
 	}
+
 	out.DecreaseIdent(4)
 }
 
diff --git a/internal/jet/column.go b/internal/jet/column.go
index 0fd59be..3e4c300 100644
--- a/internal/jet/column.go
+++ b/internal/jet/column.go
@@ -115,56 +115,3 @@ func (c ColumnExpressionImpl) serialize(statement StatementType, out *SQLBuilder
 		out.WriteIdentifier(c.name)
 	}
 }
-
-//------------------------------------------------------//
-
-// ColumnList is a helper type to support list of columns as single projection
-type ColumnList []ColumnExpression
-
-func (cl ColumnList) fromImpl(subQuery SelectTable) Projection {
-	newProjectionList := ProjectionList{}
-
-	for _, column := range cl {
-		newProjectionList = append(newProjectionList, column.fromImpl(subQuery))
-	}
-
-	return newProjectionList
-}
-
-func (cl ColumnList) serialize(statement StatementType, out *SQLBuilder, options ...SerializeOption) {
-	out.WriteString("(")
-	for i, column := range cl {
-		if i > 0 {
-			out.WriteString(", ")
-		}
-		column.serialize(statement, out, FallTrough(options)...)
-	}
-	out.WriteString(")")
-}
-
-func (cl ColumnList) serializeForProjection(statement StatementType, out *SQLBuilder) {
-	projections := ColumnListToProjectionList(cl)
-
-	SerializeProjectionList(statement, projections, out)
-}
-
-// dummy column interface implementation
-
-// Name is placeholder for ColumnList to implement Column interface
-func (cl ColumnList) Name() string { return "" }
-
-// TableName is placeholder for ColumnList to implement Column interface
-func (cl ColumnList) TableName() string                { return "" }
-func (cl ColumnList) setTableName(name string)         {}
-func (cl ColumnList) setSubQuery(subQuery SelectTable) {}
-func (cl ColumnList) defaultAlias() string             { return "" }
-
-// SetTableName is utility function to set table name from outside of jet package to avoid making public setTableName
-func SetTableName(columnExpression ColumnExpression, tableName string) {
-	columnExpression.setTableName(tableName)
-}
-
-// SetSubQuery is utility function to set table name from outside of jet package to avoid making public setSubQuery
-func SetSubQuery(columnExpression ColumnExpression, subQuery SelectTable) {
-	columnExpression.setSubQuery(subQuery)
-}
diff --git a/internal/jet/column_assigment.go b/internal/jet/column_assigment.go
new file mode 100644
index 0000000..440f3eb
--- /dev/null
+++ b/internal/jet/column_assigment.go
@@ -0,0 +1,20 @@
+package jet
+
+// ColumnAssigment is interface wrapper around column assigment
+type ColumnAssigment interface {
+	Serializer
+	isColumnAssigment()
+}
+
+type columnAssigmentImpl struct {
+	column     ColumnSerializer
+	expression Expression
+}
+
+func (a columnAssigmentImpl) isColumnAssigment() {}
+
+func (a columnAssigmentImpl) serialize(statement StatementType, out *SQLBuilder, options ...SerializeOption) {
+	a.column.serialize(statement, out, ShortName.WithFallTrough(options)...)
+	out.WriteString("=")
+	a.expression.serialize(statement, out, FallTrough(options)...)
+}
diff --git a/internal/jet/column_list.go b/internal/jet/column_list.go
new file mode 100644
index 0000000..8483c76
--- /dev/null
+++ b/internal/jet/column_list.go
@@ -0,0 +1,60 @@
+package jet
+
+// ColumnList is a helper type to support list of columns as single projection
+type ColumnList []ColumnExpression
+
+// SET creates column assigment for each column in column list. expression should be created by ROW function
+func (cl ColumnList) SET(expression Expression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     cl,
+		expression: expression,
+	}
+}
+
+func (cl ColumnList) fromImpl(subQuery SelectTable) Projection {
+	newProjectionList := ProjectionList{}
+
+	for _, column := range cl {
+		newProjectionList = append(newProjectionList, column.fromImpl(subQuery))
+	}
+
+	return newProjectionList
+}
+
+func (cl ColumnList) serialize(statement StatementType, out *SQLBuilder, options ...SerializeOption) {
+	out.WriteString("(")
+	for i, column := range cl {
+		if i > 0 {
+			out.WriteString(", ")
+		}
+		column.serialize(statement, out, FallTrough(options)...)
+	}
+	out.WriteString(")")
+}
+
+func (cl ColumnList) serializeForProjection(statement StatementType, out *SQLBuilder) {
+	projections := ColumnListToProjectionList(cl)
+
+	SerializeProjectionList(statement, projections, out)
+}
+
+// dummy column interface implementation
+
+// Name is placeholder for ColumnList to implement Column interface
+func (cl ColumnList) Name() string { return "" }
+
+// TableName is placeholder for ColumnList to implement Column interface
+func (cl ColumnList) TableName() string                { return "" }
+func (cl ColumnList) setTableName(name string)         {}
+func (cl ColumnList) setSubQuery(subQuery SelectTable) {}
+func (cl ColumnList) defaultAlias() string             { return "" }
+
+// SetTableName is utility function to set table name from outside of jet package to avoid making public setTableName
+func SetTableName(columnExpression ColumnExpression, tableName string) {
+	columnExpression.setTableName(tableName)
+}
+
+// SetSubQuery is utility function to set table name from outside of jet package to avoid making public setSubQuery
+func SetSubQuery(columnExpression ColumnExpression, subQuery SelectTable) {
+	columnExpression.setSubQuery(subQuery)
+}
diff --git a/internal/jet/column_types.go b/internal/jet/column_types.go
index 58f6751..a606a4e 100644
--- a/internal/jet/column_types.go
+++ b/internal/jet/column_types.go
@@ -6,6 +6,7 @@ type ColumnBool interface {
 	Column
 
 	From(subQuery SelectTable) ColumnBool
+	SET(boolExp BoolExpression) ColumnAssigment
 }
 
 type boolColumnImpl struct {
@@ -21,6 +22,13 @@ func (i *boolColumnImpl) From(subQuery SelectTable) ColumnBool {
 	return newBoolColumn
 }
 
+func (i *boolColumnImpl) SET(boolExp BoolExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: boolExp,
+	}
+}
+
 // BoolColumn creates named bool column.
 func BoolColumn(name string) ColumnBool {
 	boolColumn := &boolColumnImpl{}
@@ -38,6 +46,7 @@ type ColumnFloat interface {
 	Column
 
 	From(subQuery SelectTable) ColumnFloat
+	SET(floatExp FloatExpression) ColumnAssigment
 }
 
 type floatColumnImpl struct {
@@ -53,6 +62,13 @@ func (i *floatColumnImpl) From(subQuery SelectTable) ColumnFloat {
 	return newFloatColumn
 }
 
+func (i *floatColumnImpl) SET(floatExp FloatExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: floatExp,
+	}
+}
+
 // FloatColumn creates named float column.
 func FloatColumn(name string) ColumnFloat {
 	floatColumn := &floatColumnImpl{}
@@ -70,6 +86,7 @@ type ColumnInteger interface {
 	Column
 
 	From(subQuery SelectTable) ColumnInteger
+	SET(intExp IntegerExpression) ColumnAssigment
 }
 
 type integerColumnImpl struct {
@@ -86,6 +103,13 @@ func (i *integerColumnImpl) From(subQuery SelectTable) ColumnInteger {
 	return newIntColumn
 }
 
+func (i *integerColumnImpl) SET(intExp IntegerExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: intExp,
+	}
+}
+
 // IntegerColumn creates named integer column.
 func IntegerColumn(name string) ColumnInteger {
 	integerColumn := &integerColumnImpl{}
@@ -104,6 +128,7 @@ type ColumnString interface {
 	Column
 
 	From(subQuery SelectTable) ColumnString
+	SET(stringExp StringExpression) ColumnAssigment
 }
 
 type stringColumnImpl struct {
@@ -120,6 +145,13 @@ func (i *stringColumnImpl) From(subQuery SelectTable) ColumnString {
 	return newStrColumn
 }
 
+func (i *stringColumnImpl) SET(stringExp StringExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: stringExp,
+	}
+}
+
 // StringColumn creates named string column.
 func StringColumn(name string) ColumnString {
 	stringColumn := &stringColumnImpl{}
@@ -137,6 +169,7 @@ type ColumnTime interface {
 	Column
 
 	From(subQuery SelectTable) ColumnTime
+	SET(timeExp TimeExpression) ColumnAssigment
 }
 
 type timeColumnImpl struct {
@@ -152,6 +185,13 @@ func (i *timeColumnImpl) From(subQuery SelectTable) ColumnTime {
 	return newTimeColumn
 }
 
+func (i *timeColumnImpl) SET(timeExp TimeExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: timeExp,
+	}
+}
+
 // TimeColumn creates named time column
 func TimeColumn(name string) ColumnTime {
 	timeColumn := &timeColumnImpl{}
@@ -183,6 +223,13 @@ func (i *timezColumnImpl) From(subQuery SelectTable) ColumnTimez {
 	return newTimezColumn
 }
 
+func (i *timezColumnImpl) SET(timezExp TimezExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: timezExp,
+	}
+}
+
 // TimezColumn creates named time with time zone column.
 func TimezColumn(name string) ColumnTimez {
 	timezColumn := &timezColumnImpl{}
@@ -200,6 +247,7 @@ type ColumnTimestamp interface {
 	Column
 
 	From(subQuery SelectTable) ColumnTimestamp
+	SET(timestampExp TimestampExpression) ColumnAssigment
 }
 
 type timestampColumnImpl struct {
@@ -215,6 +263,13 @@ func (i *timestampColumnImpl) From(subQuery SelectTable) ColumnTimestamp {
 	return newTimestampColumn
 }
 
+func (i *timestampColumnImpl) SET(timestampExp TimestampExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: timestampExp,
+	}
+}
+
 // TimestampColumn creates named timestamp column
 func TimestampColumn(name string) ColumnTimestamp {
 	timestampColumn := &timestampColumnImpl{}
@@ -232,6 +287,7 @@ type ColumnTimestampz interface {
 	Column
 
 	From(subQuery SelectTable) ColumnTimestampz
+	SET(timestampzExp TimestampzExpression) ColumnAssigment
 }
 
 type timestampzColumnImpl struct {
@@ -247,6 +303,13 @@ func (i *timestampzColumnImpl) From(subQuery SelectTable) ColumnTimestampz {
 	return newTimestampzColumn
 }
 
+func (i *timestampzColumnImpl) SET(timestampzExp TimestampzExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: timestampzExp,
+	}
+}
+
 // TimestampzColumn creates named timestamp with time zone column.
 func TimestampzColumn(name string) ColumnTimestampz {
 	timestampzColumn := &timestampzColumnImpl{}
@@ -264,6 +327,7 @@ type ColumnDate interface {
 	Column
 
 	From(subQuery SelectTable) ColumnDate
+	SET(dateExp DateExpression) ColumnAssigment
 }
 
 type dateColumnImpl struct {
@@ -279,6 +343,13 @@ func (i *dateColumnImpl) From(subQuery SelectTable) ColumnDate {
 	return newDateColumn
 }
 
+func (i *dateColumnImpl) SET(dateExp DateExpression) ColumnAssigment {
+	return columnAssigmentImpl{
+		column:     i,
+		expression: dateExp,
+	}
+}
+
 // DateColumn creates named date column.
 func DateColumn(name string) ColumnDate {
 	dateColumn := &dateColumnImpl{}
diff --git a/internal/testutils/test_utils.go b/internal/testutils/test_utils.go
index aa53b1e..06035dd 100644
--- a/internal/testutils/test_utils.go
+++ b/internal/testutils/test_utils.go
@@ -24,12 +24,12 @@ import (
 func AssertExec(t *testing.T, stmt jet.Statement, db qrm.DB, rowsAffected ...int64) {
 	res, err := stmt.Exec(db)
 
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	rows, err := res.RowsAffected()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	if len(rowsAffected) > 0 {
-		assert.Equal(t, rows, rowsAffected[0])
+		require.Equal(t, rows, rowsAffected[0])
 	}
 }
 
@@ -224,7 +224,7 @@ func AssertFileNamesEqual(t *testing.T, fileInfos []os.FileInfo, fileNames ...st
 
 // AssertDeepEqual checks if actual and expected objects are deeply equal.
 func AssertDeepEqual(t *testing.T, actual, expected interface{}, msg ...string) {
-	assert.True(t, cmp.Equal(actual, expected), msg)
+	require.True(t, cmp.Equal(actual, expected), msg)
 }
 
 // BoolPtr returns address of bool parameter
diff --git a/mysql/insert_statement.go b/mysql/insert_statement.go
index a21089c..a4ecc94 100644
--- a/mysql/insert_statement.go
+++ b/mysql/insert_statement.go
@@ -13,13 +13,15 @@ type InsertStatement interface {
 	MODEL(data interface{}) InsertStatement
 	MODELS(data interface{}) InsertStatement
 
+	ON_DUPLICATE_KEY_UPDATE(assigments ...ColumnAssigment) InsertStatement
+
 	QUERY(selectStatement SelectStatement) InsertStatement
 }
 
 func newInsertStatement(table Table, columns []jet.Column) InsertStatement {
 	newInsert := &insertStatementImpl{}
 	newInsert.SerializerStatement = jet.NewStatementImpl(Dialect, jet.InsertStatementType, newInsert,
-		&newInsert.Insert, &newInsert.ValuesQuery)
+		&newInsert.Insert, &newInsert.ValuesQuery, &newInsert.OnDuplicateKey)
 
 	newInsert.Insert.Table = table
 	newInsert.Insert.Columns = columns
@@ -30,26 +32,55 @@ func newInsertStatement(table Table, columns []jet.Column) InsertStatement {
 type insertStatementImpl struct {
 	jet.SerializerStatement
 
-	Insert      jet.ClauseInsert
-	ValuesQuery jet.ClauseValuesQuery
+	Insert         jet.ClauseInsert
+	ValuesQuery    jet.ClauseValuesQuery
+	OnDuplicateKey onDuplicateKeyUpdateClause
 }
 
-func (i *insertStatementImpl) VALUES(value interface{}, values ...interface{}) InsertStatement {
-	i.ValuesQuery.Rows = append(i.ValuesQuery.Rows, jet.UnwindRowFromValues(value, values))
-	return i
+func (is *insertStatementImpl) VALUES(value interface{}, values ...interface{}) InsertStatement {
+	is.ValuesQuery.Rows = append(is.ValuesQuery.Rows, jet.UnwindRowFromValues(value, values))
+	return is
 }
 
-func (i *insertStatementImpl) MODEL(data interface{}) InsertStatement {
-	i.ValuesQuery.Rows = append(i.ValuesQuery.Rows, jet.UnwindRowFromModel(i.Insert.GetColumns(), data))
-	return i
+func (is *insertStatementImpl) MODEL(data interface{}) InsertStatement {
+	is.ValuesQuery.Rows = append(is.ValuesQuery.Rows, jet.UnwindRowFromModel(is.Insert.GetColumns(), data))
+	return is
 }
 
-func (i *insertStatementImpl) MODELS(data interface{}) InsertStatement {
-	i.ValuesQuery.Rows = append(i.ValuesQuery.Rows, jet.UnwindRowsFromModels(i.Insert.GetColumns(), data)...)
-	return i
+func (is *insertStatementImpl) MODELS(data interface{}) InsertStatement {
+	is.ValuesQuery.Rows = append(is.ValuesQuery.Rows, jet.UnwindRowsFromModels(is.Insert.GetColumns(), data)...)
+	return is
 }
 
-func (i *insertStatementImpl) QUERY(selectStatement SelectStatement) InsertStatement {
-	i.ValuesQuery.Query = selectStatement
-	return i
+func (is *insertStatementImpl) ON_DUPLICATE_KEY_UPDATE(assigments ...ColumnAssigment) InsertStatement {
+	is.OnDuplicateKey = assigments
+	return is
+}
+
+func (is *insertStatementImpl) QUERY(selectStatement SelectStatement) InsertStatement {
+	is.ValuesQuery.Query = selectStatement
+	return is
+}
+
+type onDuplicateKeyUpdateClause []jet.ColumnAssigment
+
+// Serialize for SetClause
+func (s onDuplicateKeyUpdateClause) Serialize(statementType jet.StatementType, out *jet.SQLBuilder, options ...jet.SerializeOption) {
+	if len(s) == 0 {
+		return
+	}
+	out.NewLine()
+	out.WriteString("ON DUPLICATE KEY UPDATE")
+	out.IncreaseIdent(24)
+
+	for i, assigment := range s {
+		if i > 0 {
+			out.WriteString(",")
+			out.NewLine()
+		}
+
+		jet.Serialize(assigment, statementType, out, jet.ShortName.WithFallTrough(options)...)
+	}
+
+	out.DecreaseIdent(24)
 }
diff --git a/mysql/insert_statement_test.go b/mysql/insert_statement_test.go
index 65c8fba..95814d2 100644
--- a/mysql/insert_statement_test.go
+++ b/mysql/insert_statement_test.go
@@ -133,3 +133,50 @@ VALUES (DEFAULT, ?);
 
 	assertStatementSql(t, stmt, expectedSQL, "two")
 }
+
+func TestInsertOnDuplicateKeyUpdate(t *testing.T) {
+	stmt := func() InsertStatement {
+		return table1.INSERT(table1Col1, table1ColFloat).
+			VALUES(DEFAULT, "two")
+	}
+
+	t.Run("empty list", func(t *testing.T) {
+		stmt := stmt().ON_DUPLICATE_KEY_UPDATE()
+		assertStatementSql(t, stmt, `
+INSERT INTO db.table1 (col1, col_float)
+VALUES (DEFAULT, ?);
+`, "two")
+	})
+
+	t.Run("one set", func(t *testing.T) {
+		stmt := stmt().ON_DUPLICATE_KEY_UPDATE(table1ColFloat.SET(Float(11.1)))
+		assertStatementSql(t, stmt, `
+INSERT INTO db.table1 (col1, col_float)
+VALUES (DEFAULT, ?)
+ON DUPLICATE KEY UPDATE col_float = ?;
+`, "two", 11.1)
+	})
+
+	t.Run("all types set", func(t *testing.T) {
+		stmt := stmt().ON_DUPLICATE_KEY_UPDATE(
+			table1ColBool.SET(Bool(true)),
+			table1ColInt.SET(Int(11)),
+			table1ColFloat.SET(Float(11.1)),
+			table1ColString.SET(String("str")),
+			table1ColTime.SET(Time(11, 23, 11)),
+			table1ColTimestamp.SET(Timestamp(2020, 1, 22, 3, 4, 5)),
+			table1ColDate.SET(Date(2020, 12, 1)),
+		)
+		assertStatementSql(t, stmt, `
+INSERT INTO db.table1 (col1, col_float)
+VALUES (DEFAULT, ?)
+ON DUPLICATE KEY UPDATE col_bool = ?,
+                        col_int = ?,
+                        col_float = ?,
+                        col_string = ?,
+                        col_time = CAST(? AS TIME),
+                        col_timestamp = TIMESTAMP(?),
+                        col_date = CAST(? AS DATE);
+`, "two", true, int64(11), 11.1, "str", "11:23:11", "2020-01-22 03:04:05", "2020-12-01")
+	})
+}
diff --git a/mysql/types.go b/mysql/types.go
index 4ef84b4..908fce5 100644
--- a/mysql/types.go
+++ b/mysql/types.go
@@ -10,3 +10,6 @@ type Projection = jet.Projection
 
 // ProjectionList can be used to create conditional constructed projection list.
 type ProjectionList = jet.ProjectionList
+
+// ColumnAssigment is interface wrapper around column assigment
+type ColumnAssigment = jet.ColumnAssigment
diff --git a/mysql/utils_test.go b/mysql/utils_test.go
index 709097d..584bfee 100644
--- a/mysql/utils_test.go
+++ b/mysql/utils_test.go
@@ -7,12 +7,14 @@ import (
 )
 
 var table1Col1 = IntegerColumn("col1")
+var table1ColBool = BoolColumn("col_bool")
 var table1ColInt = IntegerColumn("col_int")
 var table1ColFloat = FloatColumn("col_float")
+var table1ColString = StringColumn("col_string")
 var table1Col3 = IntegerColumn("col3")
 var table1ColTimestamp = TimestampColumn("col_timestamp")
-var table1ColBool = BoolColumn("col_bool")
 var table1ColDate = DateColumn("col_date")
+var table1ColTime = TimeColumn("col_time")
 
 var table1 = NewTable(
 	"db",
@@ -20,10 +22,12 @@ var table1 = NewTable(
 	table1Col1,
 	table1ColInt,
 	table1ColFloat,
+	table1ColString,
 	table1Col3,
 	table1ColBool,
 	table1ColDate,
 	table1ColTimestamp,
+	table1ColTime,
 )
 
 var table2Col3 = IntegerColumn("col3")
diff --git a/postgres/clause_test.go b/postgres/clause_test.go
index 7f64c61..5602505 100644
--- a/postgres/clause_test.go
+++ b/postgres/clause_test.go
@@ -21,11 +21,12 @@ ON CONFLICT (col_bool) DO NOTHING`)
 ON CONFLICT (col_bool) ON CONSTRAINT table_pkey DO NOTHING`)
 
 	onConflict = &onConflictClause{indexExpressions: ColumnList{table1ColBool, table2ColFloat}}
-	onConflict.WHERE(table2ColFloat.ADD(table1ColInt).GT(table1ColFloat)).DO_UPDATE(
-		SET(table1ColBool, Bool(true)).
-			SET(table1ColInt, Int(1)).
-			WHERE(table2ColFloat.GT(Float(11.1))),
-	)
+	onConflict.WHERE(table2ColFloat.ADD(table1ColInt).GT(table1ColFloat)).
+		DO_UPDATE(
+			SET(table1ColBool.SET(Bool(true)),
+				table1ColInt.SET(Int(11))).
+				WHERE(table2ColFloat.GT(Float(11.1))),
+		)
 	assertClauseSerialize(t, onConflict, `
 ON CONFLICT (col_bool, col_float) WHERE (col_float + col_int) > col_float DO UPDATE
        SET col_bool = $1,
diff --git a/postgres/conflict_action.go b/postgres/conflict_action.go
index 5ff7a19..b7e9e2e 100644
--- a/postgres/conflict_action.go
+++ b/postgres/conflict_action.go
@@ -4,16 +4,15 @@ import "github.com/go-jet/jet/internal/jet"
 
 type conflictAction interface {
 	jet.Serializer
-	SET(column jet.ColumnSerializer, expression interface{}) conflictAction
 	WHERE(condition BoolExpression) conflictAction
 }
 
 // SET creates conflict action for ON_CONFLICT clause
-func SET(column jet.ColumnSerializer, expression interface{}) conflictAction {
+func SET(assigments ...ColumnAssigment) conflictAction {
 	conflictAction := updateConflictActionImpl{}
 	conflictAction.doUpdate = jet.KeywordClause{Keyword: "DO UPDATE"}
 	conflictAction.Serializer = jet.NewSerializerClauseImpl(&conflictAction.doUpdate, &conflictAction.set, &conflictAction.where)
-	conflictAction.SET(column, expression)
+	conflictAction.set = assigments
 	return &conflictAction
 }
 
@@ -25,11 +24,6 @@ type updateConflictActionImpl struct {
 	where    jet.ClauseWhere
 }
 
-func (u *updateConflictActionImpl) SET(column jet.ColumnSerializer, expression interface{}) conflictAction {
-	u.set = append(u.set, jet.SetPair{Column: column, Value: jet.ToSerializerValue(expression)})
-	return u
-}
-
 func (u *updateConflictActionImpl) WHERE(condition BoolExpression) conflictAction {
 	u.where.Condition = condition
 	return u
diff --git a/postgres/insert_statement_test.go b/postgres/insert_statement_test.go
index d80c1a1..0761cf3 100644
--- a/postgres/insert_statement_test.go
+++ b/postgres/insert_statement_test.go
@@ -153,10 +153,10 @@ func TestInsert_ON_CONFLICT(t *testing.T) {
 		VALUES("1", "2").
 		VALUES("theta", "beta").
 		ON_CONFLICT(table1ColBool).WHERE(table1ColBool.IS_NOT_FALSE()).DO_UPDATE(
-		SET(table1ColBool, "12").
-			SET(table2ColInt, 1).
-			SET(ColumnList{table1Col1, table1ColBool}, jet.ROW(Int(2), String("two"))).
-			WHERE(table1Col1.GT(Int(2))),
+		SET(table1ColBool.SET(Bool(true)),
+			table2ColInt.SET(Int(1)),
+			ColumnList{table1Col1, table1ColBool}.SET(jet.ROW(Int(2), String("two"))),
+		).WHERE(table1Col1.GT(Int(2))),
 	).
 		RETURNING(table1Col1, table1ColBool)
 
@@ -166,7 +166,7 @@ VALUES ('one', 'two'),
        ('1', '2'),
        ('theta', 'beta')
 ON CONFLICT (col_bool) WHERE col_bool IS NOT FALSE DO UPDATE
-       SET col_bool = '12',
+       SET col_bool = TRUE,
            col_int = 1,
            (col1, col_bool) = ROW(2, 'two')
        WHERE table1.col1 > 2
@@ -180,10 +180,10 @@ func TestInsert_ON_CONFLICT_ON_CONSTRAINT(t *testing.T) {
 		VALUES("one", "two").
 		VALUES("1", "2").
 		ON_CONFLICT().ON_CONSTRAINT("idk_primary_key").DO_UPDATE(
-		SET(table1ColBool, "12").
-			SET(table2ColInt, 1).
-			SET(ColumnList{table1Col1, table1ColBool}, jet.ROW(Int(2), String("two"))).
-			WHERE(table1Col1.GT(Int(2))),
+		SET(table1ColBool.SET(Bool(false)),
+			table2ColInt.SET(Int(1)),
+			ColumnList{table1Col1, table1ColBool}.SET(jet.ROW(Int(2), String("two"))),
+		).WHERE(table1Col1.GT(Int(2))),
 	).
 		RETURNING(table1Col1, table1ColBool)
 
@@ -192,7 +192,7 @@ INSERT INTO db.table1 (col1, col_bool)
 VALUES ('one', 'two'),
        ('1', '2')
 ON CONFLICT ON CONSTRAINT idk_primary_key DO UPDATE
-       SET col_bool = '12',
+       SET col_bool = FALSE,
            col_int = 1,
            (col1, col_bool) = ROW(2, 'two')
        WHERE table1.col1 > 2
diff --git a/postgres/types.go b/postgres/types.go
index 58a8ae9..48de455 100644
--- a/postgres/types.go
+++ b/postgres/types.go
@@ -10,3 +10,6 @@ type Projection = jet.Projection
 
 // ProjectionList can be used to create conditional constructed projection list.
 type ProjectionList = jet.ProjectionList
+
+// ColumnAssigment is interface wrapper around column assigment
+type ColumnAssigment = jet.ColumnAssigment
diff --git a/tests/mysql/alltypes_test.go b/tests/mysql/alltypes_test.go
index 2f269ac..42e8aa3 100644
--- a/tests/mysql/alltypes_test.go
+++ b/tests/mysql/alltypes_test.go
@@ -991,6 +991,53 @@ func TestAllTypesInsert(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestAllTypesInsertOnDuplicateKeyUpdate(t *testing.T) {
+	tx, err := db.Begin()
+	require.NoError(t, err)
+
+	toInsert := model.AllTypes{
+		Boolean:   true,
+		Integer:   124,
+		Float:     45.67,
+		Blob:      []byte("blob"),
+		Text:      "text",
+		JSON:      "{}",
+		Time:      time.Now(),
+		Timestamp: time.Now(),
+		Date:      time.Now(),
+	}
+
+	stmt := AllTypes.INSERT(
+		AllTypes.Boolean,
+		AllTypes.Integer,
+		AllTypes.Float,
+		AllTypes.Blob,
+		AllTypes.Text,
+		AllTypes.JSON,
+		AllTypes.Time,
+		AllTypes.Timestamp,
+		AllTypes.Date,
+	).
+		MODEL(toInsert).
+		ON_DUPLICATE_KEY_UPDATE(
+			AllTypes.Boolean.SET(Bool(false)),
+			AllTypes.Integer.SET(Int(4)),
+			AllTypes.Float.SET(Float(0.67)),
+			AllTypes.Text.SET(String("new text")),
+			AllTypes.Time.SET(TimeT(time.Now())),
+			AllTypes.Timestamp.SET(TimestampT(time.Now())),
+			AllTypes.Date.SET(DateT(time.Now())),
+		)
+
+	fmt.Println(stmt.DebugSql())
+
+	_, err = stmt.Exec(tx)
+	assert.NoError(t, err)
+
+	err = tx.Rollback()
+	require.NoError(t, err)
+}
+
 var toInsert = model.AllTypes{
 	Boolean:       false,
 	BooleanPtr:    testutils.BoolPtr(true),
diff --git a/tests/mysql/insert_test.go b/tests/mysql/insert_test.go
index cb27f61..0b1fd2e 100644
--- a/tests/mysql/insert_test.go
+++ b/tests/mysql/insert_test.go
@@ -7,6 +7,8 @@ import (
 	"github.com/go-jet/jet/tests/.gentestdata/mysql/test_sample/model"
 	. "github.com/go-jet/jet/tests/.gentestdata/mysql/test_sample/table"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"math/rand"
 	"testing"
 	"time"
 )
@@ -248,6 +250,46 @@ INSERT INTO test_sample.link (url, name) (
 	assert.Equal(t, len(youtubeLinks), 2)
 }
 
+func TestInsertOnDuplicateKey(t *testing.T) {
+	randId := rand.Int31()
+
+	stmt := Link.INSERT().
+		VALUES(randId, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
+		VALUES(randId, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
+		ON_DUPLICATE_KEY_UPDATE(
+			Link.ID.SET(Link.ID.ADD(Int(11))),
+			Link.Name.SET(String("PostgreSQL Tutorial 2")),
+		)
+
+	testutils.AssertStatementSql(t, stmt, `
+INSERT INTO test_sample.link
+VALUES (?, ?, ?, DEFAULT),
+       (?, ?, ?, DEFAULT)
+ON DUPLICATE KEY UPDATE id = (id + ?),
+                        name = ?;
+`, randId, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial",
+		randId, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial",
+		int64(11), "PostgreSQL Tutorial 2")
+
+	testutils.AssertExec(t, stmt, db, 3)
+
+	newLinks := []model.Link{}
+
+	err := SELECT(Link.AllColumns).
+		FROM(Link).
+		WHERE(Link.ID.EQ(Int(int64(randId)).ADD(Int(11)))).
+		Query(db, &newLinks)
+
+	require.NoError(t, err)
+	require.Len(t, newLinks, 1)
+	require.Equal(t, newLinks[0], model.Link{
+		ID:          randId + 11,
+		URL:         "http://www.postgresqltutorial.com",
+		Name:        "PostgreSQL Tutorial 2",
+		Description: nil,
+	})
+}
+
 func TestInsertWithQueryContext(t *testing.T) {
 	cleanUpLinkTable(t)
 
diff --git a/tests/mysql/main_test.go b/tests/mysql/main_test.go
index eb19a68..c7db884 100644
--- a/tests/mysql/main_test.go
+++ b/tests/mysql/main_test.go
@@ -4,6 +4,8 @@ import (
 	"database/sql"
 	"flag"
 	"github.com/go-jet/jet/tests/dbconfig"
+	"math/rand"
+	"time"
 
 	_ "github.com/go-sql-driver/mysql"
 
@@ -28,6 +30,7 @@ func sourceIsMariaDB() bool {
 }
 
 func TestMain(m *testing.M) {
+	rand.Seed(time.Now().Unix())
 	defer profile.Start().Stop()
 
 	var err error
diff --git a/tests/postgres/insert_test.go b/tests/postgres/insert_test.go
index ecbd3c5..7367e1d 100644
--- a/tests/postgres/insert_test.go
+++ b/tests/postgres/insert_test.go
@@ -2,7 +2,6 @@ package postgres
 
 import (
 	"context"
-	"github.com/go-jet/jet/internal/jet"
 	"github.com/go-jet/jet/internal/testutils"
 	. "github.com/go-jet/jet/postgres"
 	"github.com/go-jet/jet/tests/.gentestdata/jetdb/test_sample/model"
@@ -134,8 +133,10 @@ ON CONFLICT ON CONSTRAINT employee_pkey DO NOTHING;
 			VALUES(100, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
 			VALUES(200, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
 			ON_CONFLICT(Link.ID).DO_UPDATE(
-			SET(Link.ID, Link.EXCLUDED.ID).
-				SET(Link.URL, "http://www.postgresqltutorial2.com"),
+			SET(
+				Link.ID.SET(Link.EXCLUDED.ID),
+				Link.URL.SET(String("http://www.postgresqltutorial2.com")),
+			),
 		).
 			RETURNING(Link.AllColumns)
 
@@ -161,8 +162,10 @@ RETURNING link.id AS "link.id",
 			VALUES(100, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
 			VALUES(200, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
 			ON_CONFLICT().ON_CONSTRAINT("link_pkey").DO_UPDATE(
-			SET(Link.ID, Link.EXCLUDED.ID).
-				SET(Link.URL, "http://www.postgresqltutorial2.com"),
+			SET(
+				Link.ID.SET(Link.EXCLUDED.ID),
+				Link.URL.SET(String("http://www.postgresqltutorial2.com")),
+			),
 		).
 			RETURNING(Link.AllColumns)
 
@@ -188,9 +191,13 @@ RETURNING link.id AS "link.id",
 		stmt := Link.INSERT(Link.ID, Link.URL, Link.Name, Link.Description).
 			VALUES(100, "http://www.postgresqltutorial.com", "PostgreSQL Tutorial", DEFAULT).
 			ON_CONFLICT(Link.ID).WHERE(Link.ID.MUL(Int(2)).GT(Int(10))).DO_UPDATE(
-			SET(Link.ID, SELECT(MAXi(Link.ID).ADD(Int(1))).FROM(Link)).
-				SET(ColumnList{Link.Name, Link.Description}, jet.ROW(Link.EXCLUDED.Name, String("new description"))).
-				WHERE(Link.Description.IS_NOT_NULL()),
+			SET(
+				Link.ID.SET(
+					IntExp(SELECT(MAXi(Link.ID).ADD(Int(1))).
+						FROM(Link)),
+				),
+				ColumnList{Link.Name, Link.Description}.SET(ROW(Link.EXCLUDED.Name, String("new description"))),
+			).WHERE(Link.Description.IS_NOT_NULL()),
 		)
 
 		testutils.AssertDebugStatementSql(t, stmt, `