java.sql.ResultSetMetaData.getColumnLabel和getColumnName的區別

如果將ResultSet的結果映射到HashMap中，要使用getColumnLabel，而不要用getColumnName，這樣可提高程序的健壯性

理由：

getColumnName返回的是sql語句中field的原始名字。
getColumnLabel是field的SQL AS的值（Alias--別名）。
比如：select 
          a.name as name,
          a.description as description,
          b.description as relatedDescription 
         from a,b where ...
此時,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 title

Throws:

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 name

Throws:

SQLException - if a database access error occurs