With as使用

with as 语法：
WITH TMP  AS (
   select a as id from var
)
SELECT * from TMP;

问题一：

需要打开参数_t_gcluster_support_cte，gbase> show variables like '_t_gcluster_support_cte';
若没打开该参数，则会报错：
1235 (42000): This version of GBase doesn't yet support 'CTE'

打开参数后可以正常使用
set global _t_gcluster_support_cte = 1;

问题二：

打开后，使用with as结合其他语法：
WITH TMP  AS (
   select 'wdqw' as we
)
SELECT * from TMP;
语法还是报错：
ERROR 1149 (42000): (GBA-02SC-1001) The query includes syntax that is not supported by the gcluster.

上面语法其实是select 'wdqw' as we，单独执行这句是正常可以执行的，但是在with as中会报错，因为with as 是需要内部查询的表是需要有from的，于是修改语句后，即可使用：
WITH TMP  AS (
   select 'wdqw' as we from dual
)
SELECT * from TMP;

若上面语句依旧报错，报错内容：
SQL 错误 [1142][42000]: SELECT command denied to user 'test'@'localhost' for table 'dual'

报错是因为账号无dual权限，授权后即可
grant select on gclusterdb.dual to test;