Python 蟒蛇：MYSQLdb。如何在大表中不执行select * 的情况下获取列名？
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python: MYSQLdb. how to get columns name without executing select * in a big table?
提问by MacSanhe
I want to get the column names of a table, but there a over million data in it. So I cannot use:
我想获取表的列名，但其中有超过一百万的数据。所以我不能使用：
cursor.execute("SELECT * FROM table_name")
print cursor.description
And in sqlite3, I do it this way
而在 sqlite3 中，我是这样做的
crs.execute("PRAGMA table_info(%s)" %(tablename[0]))
for info in crs:
print info
But this is not working in python mysqldb. Any one know how to do that?
但这在 python mysqldb 中不起作用。有谁知道怎么做？
采纳答案by alecxe
You can use SHOW columns:
您可以使用SHOW columns：
cursor.execute("SHOW columns FROM table_name")
print [column[0] for column in cursor.fetchall()]
FYI, this is essentially the same as using desc:
仅供参考，这与使用基本相同desc：
cursor.execute("desc table_name")
print [column[0] for column in cursor.fetchall()]
回答by ebarr
The correct way to do this would be to use "SHOW columns FROM table_name"however, you could also simply add a LIMITto your existing query:
执行此操作的正确方法是使用，"SHOW columns FROM table_name"但您也可以简单地将 a 添加LIMIT到现有查询中：
cursor.execute("SELECT * FROM table_name LIMIT 0")
print cursor.description
回答by Missing Semicolon
Try
尝试
cursor.execute("SELECT * FROM table_name LIMIT 1")
or
或者
cursor.execute("SELECT * FROM table_name WHERE 1=0")
Both prevent massive amounts of data being rattled. The second one is perhaps more elegant. I've just checked, and even this works:
两者都可以防止大量数据混乱。第二个可能更优雅。我刚刚检查过，即使这样也有效：
>>>cursor.execute("SELECT LEFT(long_text,5) as short_text FROM table_name WHERE 1=0")
>>>print cursor.description
(('short_text', 253, 0, 5, 5, 31, 0),)
回答by YH Wu
cursor.execute("SELECT * FROM table_name LIMIT 0")
cursor.column_names
Use the following to find other information
使用以下内容查找其他信息
[v for v in dir(cursor) if v.find("_")]
