key « SQL « Java Database Q&A

1. Should I use composite primary keys or not?    stackoverflow.com

There seems to only be 2nd class support for composite database keys in Java's JPA (via EmbeddedId or IdClass annotations). And when I read up on composite keys, regardless of language, ...

2. Java: How to use a pair of keys for HashMap    stackoverflow.com

From a sql database, I am reading a table with 2 fields: appName, user. So I may see:

+-------------+
| appA | John |
+-------------+
| appB | Mary |
+-------------+
| appC | Tom ...

3. Getting primary key information from Pervasive SQL    forums.oracle.com

try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newI nstance(); Connection db_connection = DriverManager.getConnection ("jdbc:odbc:MQAUPDT", "", ""); Statement db_statement = db_connection.createStatement(); String tableName = "GPRCCODE"; ResultSet rs = null; DatabaseMetaData meta = db_connection.getMetaData(); rs = meta.getPrimaryKeys(null, null, tableName); while (rs.next()) { System.out.println(rs.getString("COLUMN_NAME")); } rs.close(); } catch (Exception e) { System.out.println(e.getMessage()); } } } Can anyone tell me that whether this method works for Pervasive or not? And ...

4. Getting primary key information in Pervasive SQL    forums.oracle.com

try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newI nstance(); Connection db_connection = DriverManager.getConnection ("jdbc:odbc:MQAUPDT", "", ""); Statement db_statement = db_connection.createStatement(); String tableName = "GPRCCODE"; ResultSet rs = null; DatabaseMetaData meta = db_connection.getMetaData(); rs = meta.getPrimaryKeys(null, null, tableName); while (rs.next()) { System.out.println(rs.getString("COLUMN_NAME")); } rs.close(); } catch (Exception e) { System.out.println(e.getMessage()); } } } Can anyone tell me that whether this method works for Pervasive or not? And ...

5. Getting primary key information in Pervasive SQL    forums.oracle.com