Package com.evolveum.midpoint.repo.sqlbase

Class JdbcSession

java.lang.Object
com.evolveum.midpoint.repo.sqlbase.JdbcSession
All Implemented Interfaces:
AutoCloseable
public class JdbcSession extends Object implements AutoCloseable
Wrapper around JDBC Connection representing "session", typically a transactional one. The construction can be fluently followed by startTransaction() or its variants. Without starting the transaction connection will likely be in auto-commit mode. Use commit() or rollback() to finish the transaction. While not typical, multiple transactions can be executed in sequence (not concurrently). The next transaction starts immediately after committing/rolling back the previous one, there is no need to explicitly start another transaction if one of startTransaction() methods was called before. Using multiple transactions is in general discouraged in favour of multiple try-with-resource blocks each using new session (physical SQL connections are pooled, of course). Object is AutoCloseable and can be used in try-with-resource blocks (which is preferred). *Always commit the transaction explicitly* before the JDBC session is automatically closed, even for read-only transactions; *otherwise the transaction is just closed and default cleanup procedure of the underlying connection pool or driver is used (rollback for Hikari)*. Note: There is no simple way how to determine "active transaction" on the JDBC level, so we can't log a warning for this because it would happen every time. If database does not support read-only transactions directly, commit() executes rollback instead.

  • Constructor Details

  • Method Details

    • startTransaction

      public JdbcSession startTransaction()
      Starts transaction and returns this. *Do not forget to explicitly commit the transaction* calling commit() at the end of positive flow block, otherwise the transaction will be terminated by the connection pool automatically - which is likely a rollback.

    • startTransaction

      public JdbcSession startTransaction(int transactionLevel)
      Starts transaction with different transaction isolation level. This level will NOT be reverted to previous level after the end of transaction. It is advisable to use this only for short-lived JDBC sessions with special requirements.

    • startReadOnlyTransaction

      public JdbcSession startReadOnlyTransaction()
      Starts read-only transaction and returns this. If read-only transaction is truly supported commit, rollback or nothing can be used. Using neither commit nor rollback is perfectly OK, rollback will be likely used by the connection pool after reclaiming the connection. There should be no performance difference between commit and rollback.

    • commit

      public void commit()
      Commits current transaction. If read-only transaction is not supported by database it rolls back read-only transaction.

    • rollback

      public void rollback()
      Rolls back the transaction. See also various handle*Exception() methods that do the same thing adding exception logging and changes to the operation result.

    • executeStatement

      public void executeStatement(String sql) throws SystemException
      This is used for technical statements and throws SystemException. Don't use this for unsafe concatenated statements with parameters!
      Throws:
      SystemException

    • addColumn

      public void addColumn(String tableName, com.querydsl.sql.ColumnMetadata column)
      Alters table adding another column - intended for custom/extension columns.

    • newQuery

      public com.querydsl.sql.SQLQuery<?> newQuery()
      Creates Querydsl query based on current Querydsl configuration and session's connection.

    • newInsert

      public com.querydsl.sql.dml.SQLInsertClause newInsert(com.querydsl.sql.RelationalPath<?> entity)
      Starts insert clause for specified entity. Check Querydsl docs on insert for more about various ways how to use it.

    • newUpdate

      public com.querydsl.sql.dml.SQLUpdateClause newUpdate(com.querydsl.sql.RelationalPath<?> entity)

    • newDelete

      public com.querydsl.sql.dml.SQLDeleteClause newDelete(com.querydsl.sql.RelationalPath<?> entity)

    • getNativeTypeName

      public String getNativeTypeName(int typeCode)

    • connection

      public Connection connection()

    • sessionId

      public String sessionId()

    • databaseType

      public SupportedDatabase databaseType()

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable