Function tidbCreateIndexHelper

backend/plugin/schema/tidb/walk_through.go:1299–1356

(t *model.TableMetadata, name string, keyList []string, unique bool, tp string, option *tidbast.IndexOption)

}

func tidbCreateIndexHelper(t *model.TableMetadata, name string, keyList []string, unique bool, tp string, option *tidbast.IndexOption) *storepb.Advice {
	if len(keyList) == 0 {
		content := fmt.Sprintf("Index `%s` in table `%s` has empty key", name, t.GetProto().Name)
		return &storepb.Advice{
			Status:        storepb.Advice_ERROR,
			Code:          code.IndexEmptyKeys.Int32(),
			Title:         content,
			Content:       content,
			StartPosition: &storepb.Position{Line: 0},
		}
	}
	if name != "" {
		if t.GetIndex(name) != nil {
			content := fmt.Sprintf("Index `%s` already exists in table `%s`", name, t.GetProto().Name)
			return &storepb.Advice{
				Status:        storepb.Advice_ERROR,
				Code:          code.IndexExists.Int32(),
				Title:         content,
				Content:       content,
				StartPosition: &storepb.Position{Line: 0},
			}
		}
	} else {
		suffix := 1
		for {
			name = keyList[0]
			if suffix > 1 {
				name = fmt.Sprintf("%s_%d", keyList[0], suffix)
			}
			if t.GetIndex(name) == nil {
				break
			}
			suffix++
		}
	}

	visible := option == nil || option.Visibility != tidbast.IndexVisibilityInvisible

	index := &storepb.IndexMetadata{
		Name:        name,
		Expressions: keyList,
		Type:        tp,
		Unique:      unique,
		Primary:     false,
		Visible:     visible,
	}

	if err := t.CreateIndex(index); err != nil {
		return &storepb.Advice{
			Status:        storepb.Advice_ERROR,
			Code:          code.IndexExists.Int32(),
			Title:         err.Error(),
			Content:       err.Error(),
			StartPosition: &storepb.Position{Line: 0},
		}
	}
	return nil
}