ent/dialect/sql: add upper and lower methods

Summary: Pull Request resolved: https://github.com/facebookincubator/ent/pull/18

Reviewed By: elys1um

Differential Revision: D16916563

fbshipit-source-id: f758536103356cb5b2bacf707c7c7da931bb4560

dialect/sql/builder.go

@@ -1028,6 +1028,32 @@ func (p *Predicate) Contains(col, sub string) *Predicate {
 	return p.Like(col, "%"+sub+"%")
 }
 
+// Lower wraps the given column with the LOWER function.
+//
+//	P().EQ(sql.Lower("name"), "a8m")
+//
+func Lower(name string) string {
+	var b Builder
+	b.WriteString("LOWER")
+	b.Nested(func(b *Builder) {
+		b.Append(name)
+	})
+	return b.String()
+}
+
+// Upper wraps the given column with the UPPER function.
+//
+//	P().EQ(sql.Upper("name"), "a8m")
+//
+func Upper(name string) string {
+	var b Builder
+	b.WriteString("UPPER")
+	b.Nested(func(b *Builder) {
+		b.Append(name)
+	})
+	return b.String()
+}
+
 // Query returns query representation of a predicate.
 func (p *Predicate) Query() (string, []interface{}) {
 	return p.b.String(), p.b.args

dialect/sql/builder_test.go

@@ -234,6 +234,30 @@ func TestBuilder(t *testing.T) {
 			wantQuery: "DELETE FROM `users` WHERE (`name` = ? AND `age` = ?) OR (`name` = ? AND `age` = ?) OR ((`name` = ?) AND (`age` = ? OR `age` = ?))",
 			wantArgs:  []interface{}{"foo", 10, "bar", 20, "qux", 1, 2},
 		},
+		{
+			input: Select(Lower("name")).
+				From(Table("users")),
+			wantQuery: "SELECT LOWER(`name`) FROM `users`",
+		},
+		{
+			input: Select(Lower("name")).
+				From(Table("users")).
+				Where(EQ(Lower("name"), "a8m")),
+			wantQuery: "SELECT LOWER(`name`) FROM `users` WHERE LOWER(`name`) = ?",
+			wantArgs:  []interface{}{"a8m"},
+		},
+		{
+			input: Select(Upper("name")).
+				From(Table("users")),
+			wantQuery: "SELECT UPPER(`name`) FROM `users`",
+		},
+		{
+			input: Select(Upper("name")).
+				From(Table("users")).
+				Where(EQ(Upper("name"), "a8m")),
+			wantQuery: "SELECT UPPER(`name`) FROM `users` WHERE UPPER(`name`) = ?",
+			wantArgs:  []interface{}{"a8m"},
+		},
 		{
 			input:     Select().From(Table("users")),
 			wantQuery: "SELECT * FROM `users`",