使用带引号的表标识符时，Informix 中的 CONNECT BY 查询引发的一般语法错误

Question

在 Informix 数据库上运行以下查询时，数据库报告一般语法错误（没有任何关于导致问题的原因的指示）。相同的查询可以在 CUBRID 或 Oracle 数据库上完美运行，这两种数据库也都支持 CONNECT BY 句法：

select 
  lower(connect_by_root "t_directory"."name"), 
  connect_by_isleaf, 
  connect_by_iscycle, 
  substr(
    sys_connect_by_path(lower("t_directory"."name"), '/'), 
    2) "dir"
from "t_directory"
start with "t_directory"."parent_id" is null
connect by nocycle prior "t_directory"."id" = "t_directory"."parent_id"
order siblings by lower("t_directory"."name") asc

我使用的数据库是 Windows 上的 Informix 12.10 开发人员版本。我使用以下连接 URL 从 JDBC 驱动程序运行查询（以允许带引号的表标识符）：

jdbc:informix-sqli://localhost:9092/test:INFORMIXSERVER=ol_informix;DELIMIDENT=y

Answer 1

这里确切的问题是 prior 不接受带引号的表标识符，尽管带引号的列标识符似乎没问题。这个查询运行得很好：

select 
  lower(connect_by_root "t_directory"."name"), 
  connect_by_isleaf, 
  connect_by_iscycle, 
  substr(
    sys_connect_by_path(lower("t_directory"."name"), '/'), 
    2) "dir"
from "t_directory"
start with "t_directory"."parent_id" is null
connect by nocycle prior t_directory."id" = "t_directory"."parent_id"
order siblings by lower("t_directory"."name") asc

...区别在于：

-- Bad:
connect by nocycle prior "t_directory"."id" = "t_directory"."parent_id"

-- Good:
connect by nocycle prior t_directory."id" = "t_directory"."parent_id"