public static String updateSetColumns(Class<?> entityClass, String entityName, boolean notNull, boolean notEmpty) {
        StringBuilder sql = new StringBuilder();
        sql.append("<set>");
        //获取全部列
        Set<EntityColumn> columnSet = EntityHelper.getColumns(entityClass);
        //对乐观锁的支持
        EntityColumn versionColumn = null;
        //当某个列有主键策略时，不需要考虑他的属性是否为空，因为如果为空，一定会根据主键策略给他生成一个值
        for (EntityColumn column : columnSet) {
            if (column.getEntityField().isAnnotationPresent(Version.class)) {
                if (versionColumn != null) {
                    throw new VersionException(entityClass.getCanonicalName() + " 中包含多个带有 @Version 注解的字段，一个类中只能存在一个带有 @Version 注解的字段!");
                }
                versionColumn = column;
            }
            if (!column.isId() && column.isUpdatable()) {
                if (column == versionColumn) {
                    Version version = versionColumn.getEntityField().getAnnotation(Version.class);
                    String versionClass = version.nextVersion().getCanonicalName();
                    //version = ${@tk.mybatis.mapper.version@nextVersionClass("versionClass", version)}
                    sql.append(column.getColumn())
                            .append(" = ${@tk.mybatis.mapper.version.VersionUtil@nextVersion(")
                            .append("@").append(versionClass).append("@class, ")

.append(StringUtil.isEmpty(entityName)?"":entityName+".") //修复BUG
                            .append(column.getProperty()).append(")},");
                } else if (notNull) {
                    sql.append(SqlHelper.getIfNotNull(entityName, column, column.getColumnEqualsHolder(entityName) + ",", notEmpty));
                } else {
                    sql.append(column.getColumnEqualsHolder(entityName) + ",");
                }
            } else if(column.isId() && column.isUpdatable()){
                //set id = id,
                sql.append(column.getColumn()).append(" = ").append(column.getColumn()).append(",");
            }
        }
        sql.append("</set>");
        return sql.toString();
    }