package metadata

func listInternalFieldTypes() []*FieldType {
	return []*FieldType{
		&FieldType{
			Name:        "_bool",
			DatamanType: Bool,
		},
		&FieldType{
			Name:        "_datetime",
			DatamanType: DateTime,
		},
		&FieldType{
			Name:        "_document",
			DatamanType: Document,
		},
		&FieldType{
			Name:        "_int",
			DatamanType: Int,
		},
		&FieldType{
			Name:        "_string",
			DatamanType: String,
		},
		&FieldType{
			Name:        "_text",
			DatamanType: String,
		},
	}
}

package metadata

func listInternalFieldTypes() []*FieldType {
	return []*FieldType{
		&FieldType{
			Name:        "_bool",
			DatamanType: Bool,
		},
		&FieldType{
			Name:        "_datetime",
			DatamanType: DateTime,
		},
		&FieldType{
			Name:        "_document",
			DatamanType: Document,
		},
		&FieldType{
			Name:        "_int",
			DatamanType: Int,
		},
		&FieldType{
			Name:        "_string",
			DatamanType: String,
		},
		&FieldType{
			Name:        "_text",
			DatamanType: String,
		},

		// TODO: move out to database?
		&FieldType{
			Name:        "age",
			DatamanType: Int,
			Constraints: []*ConstraintInstance{
				&ConstraintInstance{
					Type: LessThan,
					Args: map[string]interface{}{"value": 200},
				},
			},
		},
	}
}

Add example type with constraint
Add example type with constraint
