Result Sets
You can use ResultSetMetaData to retrieve metadata about the results of a query.
The query can contain any of the following:
- Joins
- Aggregates
- Aliases
- Fully qualified names
- Generated columns
You can instantiate a ResultSetMetaData object by invoking the getMetaData method of the Statement class. A ResultSetMetaData instance is populated with data after the statement has been executed. The following query prints out the columns in the result of the query:
String connectionString = "jdbc:hdfs:Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;"; Connection conn = DriverManager.getConnection(connectionString); PreparedStatement pstmt = conn.prepareStatement("SELECT FileId, ChildrenNum AS My_ChildrenNum, GETDATE() FROM Files WHERE FileId = '119116'"); pstmt.executeQuery(); ResultSetMetaData rs = pstmt.getMetaData(); for(int i=1;i<=rs.getColumnCount();i++) { System.out.println(rs.getColumnName(i)); }