当表格为空时在cx_oracle中获取列信息？

Question

我正在为python日志记录模块的处理程序工作。这本质上是登录到Oracle数据库。

我正在使用cx_oracle，而我不知道如何得到的是列表值为空时的列值。

cursor.execute('select * from FOO') 
for row in cursor: 
    # this is never executed because cursor has no rows 
    print '%s\n' % row.description 

# This prints none 
row = cursor.fetchone() 
print str(row) 

row = cursor.fetchvars 
# prints useful info 
for each in row: 
    print each 

输出是：

None 
<cx_Oracle.DATETIME with value [None, None, None, None, None, None, None, None, None, None, None, None, None, None, None 
, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None 
, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None]> 
<cx_Oracle.STRING with value [None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, 
None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, None, 
None, None, None, None, None, None, None, None, None, None, None, None, None, None, None]> 

现在看VAR数据，我可以看到的数据类型，以及它们的大小（计数诺内斯？），但多数民众赞成缺少列名。

我该怎么办？

Answer 1

我认为description属性可能是你正在寻找的。这将返回描述返回数据列的元组列表。如果没有行返回，它会很愉快地工作，例如：

 
>>> import cx_Oracle 
>>> c = cx_Oracle.connect("username", "password") 
>>> cr = c.cursor() 
>>> cr.execute("select * from dual where 1=0") 
<__builtin__.OracleCursor on <cx_Oracle.Connection to user username@local>> 
>>> cr.description 
[('DUMMY', <type 'cx_Oracle.STRING'>, 1, 1, 0, 0, 1)]