Question

我的主键声明为：

id bigint PRIMARY KEY

我想提取某个ID，并希望进一步使用它。

localid = cursor.fetchone()[0]
print type(localid)
query1 = ("Select * from table_name WHERE id= %d;")
cursor.execute(query1, localid)
query2 = ("Select * from table_name WHERE id= 1;")
cursor.execute(query2)

type(localid)目前打印为int，其中获取的值仅为2或3或45。
query2在query2不起作用时不起作用。
%d是正确的说明符吗？我不这么认为。
如果提取的数字确实超出了正常int的范围，那么%d会是正确的吗？如果没有，该怎么用？

额外信息：使用Mysql-python连接器包。 Python 2.7

Answer 1

如果您使用的是MySQLdb，则%s功能中只需要execute。

您的Mysql-python确实是MySQLdb。

<强>解决方法1 `：

query1 = ("Select * from table_name WHERE id= %s;")
cursor.execute(query1, (localid,))

Note: If args is a sequence, then %s must be used as the
      parameter placeholder in the query. If a mapping is used,
      %(key)s must be used as the placeholder.

<强>溶液2 ：

query1 = ("Select * from table_name WHERE id= %d;" % localid)
cursor.execute(query1)

在Mysqldb.cursors

中

详细说明

class BaseCursor(__builtin__.object)
 |  A base for Cursor classes. Useful attributes:
 |  
 |  description
 |      A tuple of DB API 7-tuples describing the columns in
 |      the last executed query; see PEP-249 for details.
 |  
 |  description_flags
 |      Tuple of column flags for last query, one entry per column
 |      in the result set. Values correspond to those in
 |      MySQLdb.constants.FLAG. See MySQL documentation (C API)
 |      for more information. Non-standard extension.
 |  
 |  arraysize
 |      default number of rows fetchmany() will fetch
 |  
 |  Methods defined here:
 |  execute(self, query, args=None)
 |      Execute a query.
 |      
 |      query -- string, query to execute on server
 |      args -- optional sequence or mapping, parameters to use with query.
 |      
 |      Note: If args is a sequence, then %s must be used as the   #notice
 |      parameter placeholder in the query. If a mapping is used,
 |      %(key)s must be used as the placeholder.
 |      
 |      Returns long integer rows affected, if any
 |

bigint of mysql-python的格式说明符

1 个答案: