implement orderBy for SqlFunction

dialect/postgres/postgres_test.go

@@ -551,6 +551,27 @@ func (pt *postgresTest) TestWindowFunction() {
 	}, entries)
 }
 
+func (pt *postgresTest) TestOrderByFunction() {
+	ds := pt.db.From("entry").
+		Select(goqu.ROW_NUMBER().Over(goqu.W()).As("id")).Window().Order(goqu.ROW_NUMBER().Over(goqu.W()).Desc())
+
+	var entries []entry
+	pt.NoError(ds.ScanStructs(&entries))
+
+	pt.Equal([]entry{
+		{ID: 10},
+		{ID: 9},
+		{ID: 8},
+		{ID: 7},
+		{ID: 6},
+		{ID: 5},
+		{ID: 4},
+		{ID: 3},
+		{ID: 2},
+		{ID: 1},
+	}, entries)
+}
+
 func TestPostgresSuite(t *testing.T) {
 	suite.Run(t, new(postgresTest))
 }

exp/exp.go

@@ -394,6 +394,7 @@ type (
 		Aliaseable
 		Rangeable
 		Comparable
+		Orderable
 		Isable
 		Inable
 		Likeable
@@ -414,6 +415,7 @@ type (
 		Aliaseable
 		Rangeable
 		Comparable
+		Orderable
 		Isable
 		Inable
 		Likeable

exp/func.go

@@ -78,3 +78,6 @@ func (sfe sqlFunctionExpression) Over(we WindowExpression) SQLWindowFunctionExpr
 func (sfe sqlFunctionExpression) OverName(windowName IdentifierExpression) SQLWindowFunctionExpression {
 	return NewSQLWindowFunctionExpression(sfe, windowName, nil)
 }
+
+func (sfe sqlFunctionExpression) Asc() OrderedExpression  { return asc(sfe) }
+func (sfe sqlFunctionExpression) Desc() OrderedExpression { return desc(sfe) }

exp/func_test.go

@@ -70,6 +70,8 @@ func (sfes *sqlFunctionExpressionSuite) TestAllOthers() {
 		{Ex: fn.IsNotTrue(), Expected: NewBooleanExpression(IsNotOp, fn, true)},
 		{Ex: fn.IsFalse(), Expected: NewBooleanExpression(IsOp, fn, false)},
 		{Ex: fn.IsNotFalse(), Expected: NewBooleanExpression(IsNotOp, fn, false)},
+		{Ex: fn.Desc(), Expected: desc(fn)},
+		{Ex: fn.Asc(), Expected: asc(fn)},
 	}
 
 	for _, tc := range testCases {

exp/window_func.go

@@ -87,6 +87,9 @@ func (swfe sqlWindowFunctionExpression) IsNotTrue() BooleanExpression  { return
 func (swfe sqlWindowFunctionExpression) IsFalse() BooleanExpression    { return is(swfe, false) }
 func (swfe sqlWindowFunctionExpression) IsNotFalse() BooleanExpression { return isNot(swfe, false) }
 
+func (swfe sqlWindowFunctionExpression) Asc() OrderedExpression  { return asc(swfe) }
+func (swfe sqlWindowFunctionExpression) Desc() OrderedExpression { return desc(swfe) }
+
 func (swfe sqlWindowFunctionExpression) Func() SQLFunctionExpression {
 	return swfe.fn
 }

exp/window_func_test.go

@@ -96,6 +96,8 @@ func (swfet *sqlWindowFunctionExpressionTest) TestAllOthers() {
 		{Ex: wf.IsNotTrue(), Expected: NewBooleanExpression(IsNotOp, wf, true)},
 		{Ex: wf.IsFalse(), Expected: NewBooleanExpression(IsOp, wf, false)},
 		{Ex: wf.IsNotFalse(), Expected: NewBooleanExpression(IsNotOp, wf, false)},
+		{Ex: wf.Desc(), Expected: desc(wf)},
+		{Ex: wf.Asc(), Expected: asc(wf)},
 	}
 
 	for _, tc := range testCases {