ResultSet Column Name Problem in pgjdbc2.jar?
От | Mike Abraham |
---|---|
Тема | ResultSet Column Name Problem in pgjdbc2.jar? |
Дата | |
Msg-id | 3D9B7CFE.9010307@firehosesoftware.com обсуждение исходный текст |
Ответы |
Re: ResultSet Column Name Problem in pgjdbc2.jar?
|
Список | pgsql-jdbc |
I've searched the archives for help on this, but come up empty. My apologies if this problem has already been addressed. In a nutshell, my problem is this: A resultset returned from a query containing table & column names (as opposed to column names alone) contains only the column names (rather than table & column names). Here's a simplified version of the code that's giving me a problem: ... ResultSet rs = stmt.executeQuery( "select users.id, users.class, items.class " + "from users " + "left join items on (users.id = items.id)"); while (rs.next()) { System.out.println( rs.getInt("users.user_id") + " | " + rs.getInt("users.class") + " | " + rs.getInt("items.class")); } ... You get the picture. I'm joining on the 'id' column of tables 'users' and 'items' in order to return the values in their respective 'class' fields. This works like a dream in MySQL, both via the admin query tool, as well as my java code. It works with the pgAdmin query tool, but my java code gives the following error: "The column name transactions.transaction_id not found. at org.postgresql.jdbc2.ResultSet.findColumn(ResultSet.java:821) at org.postgresql.jdbc2.ResultSet.getInt(ResultSet.java:574)" Here's why. The query passes through to the database just fine, the ResultSet that's returned, however, only has the column names, without the table prefixes, in its Fields collection. In other words, taking a look at the Fields collection in the debugger shows 3 fields: Fields(0) = "user_id", Fields(1) = "class", Fields(2) = "class". Running against the MySQL JDBC driver gives the proper result, including the table prefixes: Fields(0) = "users.user_id", Fields(1) = "users.class", Fields(2) = "items.class". So, in order to use the PostgreSQL driver, you gotta reference all columns in a ResultSet by column number, not name. This is not a huge problem, of course, but I thought I should make you aware of it. Thanks for your attention. Mike Abraham
В списке pgsql-jdbc по дате отправления: