需要Oracle sqlldr TRAILING NULLCOLS,但为什么呢？

Question

我有一个深奥的sqlldr问题困扰着我.我的控制文件看起来像这样:

load data
infile 'txgen.dat'
into table TRANSACTION_NEW
fields terminated by "," optionally enclosed by '"'
TRAILING NULLCOLS
( A,
  B,
  C,
  D,
  ID "ID_SEQ.NEXTVAL"
)

数据是这样的:

a,b,c,
a,b,,d
a,b,,
a,b,c,d

如果我没有把TRAILING NULLCOLS放入,我得到"在逻辑记录结束之前找不到列"错误.但是虽然有些列是空的,但是逗号都在那里,所以我没有看到sqlldr错误解释输入文件的原因,并且没有到达它从数据库序列生成ID的结尾.

这个语法之前没有空列 - 为什么空列导致sqlldr无法到达生成的列？

我有它的工作,我只想了解为什么!？!

Answer 1

您已在控制文件中定义了5个字段.您的字段以逗号结束,因此除非指定TRAILING NULLCOLS,否则您需要在5个字段的每个记录中使用5个逗号,即使您通过SQL字符串加载带有序列值的ID字段.

RE:OP评论

这不是我的简短测试经验.使用以下控制文件:

load data
infile *
into table T_new
fields terminated by "," optionally enclosed by '"'
( A,
  B,
  C,
  D,
  ID "ID_SEQ.NEXTVAL"
)
BEGINDATA
1,1,,,
2,2,2,,
3,3,3,3,
4,4,4,4,,
,,,,,

产生以下输出:

Table T_NEW, loaded from every logical record.
Insert option in effect for this table: INSERT

   Column Name                  Position   Len  Term Encl Datatype
------------------------------ ---------- ----- ---- ---- ---------------------
A                                   FIRST     *   ,  O(") CHARACTER            
B                                    NEXT     *   ,  O(") CHARACTER            
C                                    NEXT     *   ,  O(") CHARACTER            
D                                    NEXT     *   ,  O(") CHARACTER            
ID                                   NEXT     *   ,  O(") CHARACTER            
    SQL string for column : "ID_SEQ.NEXTVAL"

Record 1: Rejected - Error on table T_NEW, column ID.
Column not found before end of logical record (use TRAILING NULLCOLS)
Record 2: Rejected - Error on table T_NEW, column ID.
Column not found before end of logical record (use TRAILING NULLCOLS)
Record 3: Rejected - Error on table T_NEW, column ID.
Column not found before end of logical record (use TRAILING NULLCOLS)
Record 5: Discarded - all columns null.

Table T_NEW:
  1 Row successfully loaded.
  3 Rows not loaded due to data errors.
  0 Rows not loaded because all WHEN clauses were failed.
  1 Row not loaded because all fields were null.

请注意,正确加载的唯一行有5个逗号.即使是第3行,除了ID之外还存在所有数据值,数据也不会加载.除非我遗漏了什么......

我正在使用10gR2.