ent/schema: allow setting collation for string fields

Reviewed By: a8m

Differential Revision: D17090481

fbshipit-source-id: a08768c9bac4318a91bc6a067c85d6eb022c3024

schema/field/field.go

@@ -118,6 +118,7 @@ type Descriptor struct {
 	Name          string        // field name.
 	Type          Type          // field type.
 	Charset       string        // string charset.
+	Collation     string        // string collation.
 	Unique        bool          // unique index of field.
 	Nillable      bool          // nillable struct field.
 	Optional      bool          // nullable field in database.
@@ -244,13 +245,20 @@ func (b *stringBuilder) StructTag(s string) *stringBuilder {
 	return b
 }
 
-// SetCharset sets the character set attribute for character fields.
+// Charset sets the character set attribute for character fields.
 // For example, utf8 or utf8mb4 in MySQL.
 func (b *stringBuilder) Charset(s string) *stringBuilder {
 	b.desc.Charset = s
 	return b
 }
 
+// Collation sets the collation attribute for character fields.
+// For example, utf8_general_ci or utf8mb4_bin in MySQL.
+func (b *stringBuilder) Collation(c string) *stringBuilder {
+	b.desc.Collation = c
+	return b
+}
+
 // Descriptor implements the ent.Field interface by returning its descriptor.
 func (b *stringBuilder) Descriptor() *Descriptor {
 	return b.desc

schema/field/field_test.go

@@ -88,6 +88,13 @@ func TestCharset(t *testing.T) {
 	assert.Equal(t, "utf8", fd.Charset)
 }
 
+func TestCollation(t *testing.T) {
+	fd := field.String("name").
+		Collation("utf8_general_ci").
+		Descriptor()
+	assert.Equal(t, "utf8_general_ci", fd.Collation)
+}
+
 func TestTime(t *testing.T) {
 	now := time.Now()
 	fd := field.Time("created_at").