JDBC API Usage
Jump to navigation
Jump to search
Internal
JDBC Connection Life Cycle
Database Metadata
The database metadata is an object that contains metadata about the database the current connection belongs to.
Connection c = ...;
DatabaseMetaData dmd = c.getMetaData();
ResultSet
Some implementation will fail on ResultSet.first() invocation, if the result sent is not explicitly created to be ResultSet.TYPE_SCROLL_INSENSITIVE. Creating scrollable ResultSets may have performance implications. ResultSet.next() is always safe to use, in an integrator pattern.
Query
...
private DataSource dataSource;
...
Connection c;
try {
c = dataSource.getConnection();
PreparedStatement s = c.prepareStatement("SELECT * FROM SOME_TABLE");
ResultSet rs = s.executeQuery();
while(rs.next()) {
//
// columns are 1-based
//
String column1Value = rs.getString(1);
Long column2Value = rs.getLong(2);
...
}
}
finally {
c.close();
}
More low-level JDBC code example with comments in SIA page 57.