c_10_4_obtaining_statement

🧠 10.4 Obtaining a Statement

• We can easily obtain a statement from a connection:

Statement stmt = conn.createStatement();

• Here is another retrieval of statement needed for the exam:

Statement stmt = conn.createStatement(
  ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);

• The first parameter specifies the ResultSet type
• The second parameter specified the ResultSet concurrency mode

🟥 10.4.1 Choosing a ResultSet Type

• The default ResultSet type is TYPE_FORWARD_ONLY - you can go through the data in the order it was retrieved
• TYPE_SCROLL_SENSITIVE and TYPE_SCROLL_INSENSITIVE allow you to go through the data in any order - forwards or backwards
  • TYPE_SCROLL_SENSITIVE lets you see the latest data as it is being updated - most databases do not support this
  • TYPE_SCROLL_INSENSITIVE gives you a static view of the data returned when it was query

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🟥 10.4.2 Choosing a ResultSet Concurrency Mode

• The default ResultSet mode is CONCUR_READ_ONLY - you can NOT update the result set.
  • Most of the time you will use an insert/update/delete method anyway
• CONCUR_UPDATABLE mode lets you modify the db THROUGH the result set - not supported by all Drivers