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JDBC – some remarks

JDBC – some remarks. Statement vs. PreparedStatement. Statement vs. PreparedStatement. PreparedStatement – more efficient when query executed repeatedly (possibly with different parameter values) the server creates the execution plan only once. Not always – depends on implementation

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JDBC – some remarks

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  1. JDBC – some remarks

  2. Statement vs. PreparedStatement

  3. Statement vs. PreparedStatement • PreparedStatement– more efficient when query executed repeatedly (possibly with different parameter values) • the server creates the execution plan only once. • Not always – depends on implementation • Statement – threat of SQL injection

  4. Closing JDBC resources • conn.close() may not close the connection if the connection has some JDBC resources open. Don’t rely on assumption that conn.close() should close them !!! • => rs.close(); stmt.close(); conn.close()

  5. Comparison of access methods

  6. Connection and ResultSet • Don’t share connection among multiple threads • ResultSetrs = stmnt.executeQuery(); • rs may reference an object owned by the JDBC driver => danger of a deadlock • Another reason why connection shall not be shared: • The transaction is bound to the connection

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