作者Harifucks (疝气)
看板java
标题[问题] 请问同时在同一个资料库读取多个资料表
时间Sat Aug 19 19:43:33 2006
假设我要从同一个资料库，同时得出三个资料表，请问一下最好的方法是？
方法一：
connection1 = DriverManager.getConnection(url, username, password);
statement1 = connection1.createStatement();
resultSet1 = statement1.executeQuery(sqlCmd1);
connection2 = DriverManager.getConnection(url, username, password);
statement2 = connection2.createStatement();
resultSet2 = statement2.executeQuery(sqlCmd2);
connection3 = DriverManager.getConnection(url, username, password);
statement3 = connection3.createStatement();
resultSet3 = statement3.executeQuery(sqlCmd3);
这没问题.............
方法二：
connection1 = DriverManager.getConnection(url, username, password);
statement1 = connection1.createStatement();
resultSet1 = statement1.executeQuery(sqlCmd1);
statement2 = connection1.createStatement();
resultSet2 = statement2.executeQuery(sqlCmd2);
statement3 = connection1.createStatement();
resultSet3 = statement3.executeQuery(sqlCmd3);
这我没试过...........
方法三：
connection1 = DriverManager.getConnection(url, username, password);
statement1 = connection1.createStatement();
resultSet1 = statement1.executeQuery(sqlCmd1);
resultSet2 = statement1.executeQuery(sqlCmd2);
resultSet3 = statement1.executeQuery(sqlCmd3);
这在run time有问题............
会问这样的问题是因为要考虑到变数宣告和close的问题。
到底那个方法好，谢谢。
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