Question

在HSQLDB中，我有两个TEXT表，它们映射到CSV文件。参见项目CSV Cruncher。

CREATE TEXT TABLE session_telephony_pins ( Op VARCHAR(4092), id ... )

我正在尝试在此“输入”表中添加一列，以使结果在每个表中都具有唯一的ID。

这似乎很合乎逻辑：添加定义为序列的列

CREATE TEXT TABLE output ( crunchCounter BIGINT
  GENERATED BY DEFAULT AS SEQUENCE crunchCounter PRIMARY KEY, op VARCHAR(4092), ... )

，然后使用null来让数据库选择值：

INSERT INTO output (SELECT NULL AS crunchCounter, * FROM apollo_session_occurrence)
-- I also tried withhout `AS ...`

但是如果失败，则：

SQLSyntaxErrorException duplicate column name in derived table

表和列类型：

* APOLLO_SESSION_OCCURRENCE
  - OP                           CHARACTER VARYING
  - SESSION_OCCURRENCE_ID        SMALLINT
  - SESSION_ID                   SMALLINT
  - START_TIME                   TIMESTAMP
  - END_TIME                     TIMESTAMP
  - UID                          UUID
* OUTPUT
  - CRUNCHCOUNTER                BIGINT
  - OP                           CHARACTER VARYING
  - SESSION_OCCURRENCE_ID        CHARACTER VARYING
  - SESSION_ID                   CHARACTER VARYING
  - START_TIME                   CHARACTER VARYING
  - END_TIME                     CHARACTER VARYING
  - UID                          CHARACTER VARYING

我认为这在MySQL中是可行的，但尚未经过测试。

类型应该不成问题。如果我放下crunchCounter列而只做INSERT INTO output (SELECT * FROM apollo_session_occurrence)，它就可以正常工作。

从理论上讲，我可以使用NEXT VALUE FOR crunchCounter，但这不会更改列的元数据。 HSQLDB检查元数据时会发生这种情况。

这是怎么回事？而且，

如何用唯一列填充output表？

编辑：有趣的是，它可以与其他表以及特别命名的结果列配合使用：

INSERT INTO output (SELECT NULL AS crunchCounter,  jobName, buildNumber, config, ar, arFile, deployDur, warmupDur, scale,
  CAST(warmupDur AS DOUBLE) / CAST(deployDur AS DOUBLE) AS warmupSlower
  FROM concat ORDER BY deployDur)

* CONCAT
 - JOBNAME                      CHARACTER VARYING
 - BUILDNUMBER                  SMALLINT
 - CONFIG                       CHARACTER VARYING
 - AR                           CHARACTER VARYING
 - ARFILE                       CHARACTER VARYING
 - DEPLOYDUR                    SMALLINT
 - WARMUPDUR                    SMALLINT
 - SCALE                        SMALLINT
* OUTPUT
 - CRUNCHCOUNTER                BIGINT
 - JOBNAME                      CHARACTER VARYING
 - BUILDNUMBER                  CHARACTER VARYING
 - CONFIG                       CHARACTER VARYING
 - AR                           CHARACTER VARYING
 - ARFILE                       CHARACTER VARYING
 - DEPLOYDUR                    CHARACTER VARYING
 - WARMUPDUR                    CHARACTER VARYING
 - SCALE                        CHARACTER VARYING
 - WARMUPSLOWER                 CHARACTER VARYING

开始看起来像是HSQLDB错误。

Answer 1

想通了。问题在于HSQLDB将*中的SELECT 1 AS foo, * FROM myTable扩展为foo, foo, myTable.col1, ...。

那是IMO的错误。编辑：不是错误，但是HSQLDB可以给出更好的错误消息。

解决方法：使用合格的通配符。

INSERT INTO output (SELECT NULL AS crunchCounter, 
        apollo_session_occurrence.* 
   FROM apollo_session_occurrence ...)

HSQLDB：INSERT INTO ...（SELECT NULL，* FROM）导致“重复的列名”

1 个答案: