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java.sql.ResultSetMetaData.getColumnLabel和getColumnName的区别

2014-11-13 10:02 519 查看
如果将ResultSet的结果映射到HashMap中,要使用getColumnLabel,而不要用getColumnName,这样可提高程序的健壮性

理由:

getColumnName返回的是sql语句中field的原始名字。
getColumnLabel是field的SQL AS的值(Alias--别名)。
比如:select
a.name as name,
a.description as description,
b.description as relatedDescription
from a,b where ...
此时,getColumnName(3) == "description";而getColumnLabel(3) == "relatedDescription"。

API:

getColumnLabel

String getColumnLabel(int column)
throws SQLException

Gets the designated column's suggested title for use in printouts and displays. The suggested title is usually specified by the SQL
AS
clause
. If a SQL
AS
is not specified, the value returned from
getColumnLabel
will be the same as the value returned by the
getColumnName
method.

Parameters:
column
- the first column is 1, the second is 2, ...Returns:the suggested column titleThrows:
SQLException
- if a database access error occurs

getColumnName

String getColumnName(int column)
throws SQLException

Get the designated column's name.
Parameters:

column
- the first column is 1, the second is 2, ...Returns:column nameThrows:
SQLException
- if a database access error occurs

http://blog.sina.com.cn/s/blog_735ef3790100qmf3.html
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