fork github.com/doug-martin

exp/update.go

@@ -0,0 +1,73 @@
+package exp
+
+import (
+	"reflect"
+	"sort"
+
+	"git.fsdpf.net/go/db/v2/internal/errors"
+	"git.fsdpf.net/go/db/v2/internal/util"
+)
+
+type (
+	update struct {
+		col IdentifierExpression
+		val interface{}
+	}
+)
+
+func set(col IdentifierExpression, val interface{}) UpdateExpression {
+	return update{col: col, val: val}
+}
+
+func NewUpdateExpressions(update interface{}) (updates []UpdateExpression, err error) {
+	if us, ok := update.([]UpdateExpression); ok {
+		updates = append(updates, us...)
+		return updates, nil
+	}
+	if u, ok := update.(UpdateExpression); ok {
+		updates = append(updates, u)
+		return updates, nil
+	}
+	updateValue := reflect.Indirect(reflect.ValueOf(update))
+	switch updateValue.Kind() {
+	case reflect.Map:
+		keys := util.ValueSlice(updateValue.MapKeys())
+		sort.Sort(keys)
+		for _, key := range keys {
+			updates = append(updates, ParseIdentifier(key.String()).Set(updateValue.MapIndex(key).Interface()))
+		}
+	case reflect.Struct:
+		return getUpdateExpressionsStruct(updateValue)
+	default:
+		return nil, errors.New("unsupported update interface type %+v", updateValue.Type())
+	}
+	return updates, nil
+}
+
+func getUpdateExpressionsStruct(value reflect.Value) (updates []UpdateExpression, err error) {
+	r, err := NewRecordFromStruct(value.Interface(), false, true)
+	if err != nil {
+		return updates, err
+	}
+	cols := r.Cols()
+	for _, col := range cols {
+		updates = append(updates, ParseIdentifier(col).Set(r[col]))
+	}
+	return updates, nil
+}
+
+func (u update) Expression() Expression {
+	return u
+}
+
+func (u update) Clone() Expression {
+	return update{col: u.col.Clone().(IdentifierExpression), val: u.val}
+}
+
+func (u update) Col() IdentifierExpression {
+	return u.col
+}
+
+func (u update) Val() interface{} {
+	return u.val
+}