io.ebean.config.dbplatform.DbHistorySupport Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of ebean Show documentation

composite of common runtime dependencies for all platforms

There is a newer version: 15.8.1

package io.ebean.config.dbplatform;

/**
 * History support for the database platform.
 */
public interface DbHistorySupport {

  /**
   * Return true if the implementation is SQL2011 standards based.
   * 
   * Non standards based means we need to add additional predicates into the
   * JOIN ON clause and add an additional predicate for the base table.
   * 
   */
  boolean isStandardsBased();

  /**
   * Return the number of columns bound in a 'As Of' predicate.
   * 
   * This is 1 for more standard sql2011 style and Postgres which has the
   * special range type and 2 for view based solutions with 2 columns such as
   * MySql.
   * 
   */
  int getBindCount();

  /**
   * For sql2011 style this ignores the passed in view suffix and returns something
   * like the ' as of timestamp ?' clause to be appended after the base table name.
   *
   * @param asOfViewSuffix the configured view suffix (typically "_with_history").
   * @return The suffix appended after the base table name in the from and join clauses.
   */
  String getAsOfViewSuffix(String asOfViewSuffix);

  /**
   * Return the 'versions between timestamp' suffix.
   */
  String getVersionsBetweenSuffix(String asOfViewSuffix);

  /**
   * Return the 'as of' predicate added for the given table alias.
   *
   * @param tableAlias The table alias this predicate is added for
   * @param sysPeriod  The name of the 'sys_period' column used for effective date time range.
   * @return The predicate containing a single ? bind parameter which will be bound to the 'as at' timestamp value
   */
  String getAsOfPredicate(String tableAlias, String sysPeriod);

  /**
   * Return the column for the system period lower bound that will be included in findVersions() queries.
   *
   * @param tableAlias the table alias which will typically be 't0'
   * @param sysPeriod  the name of the sys_period column
   */
  String getSysPeriodLower(String tableAlias, String sysPeriod);

  /**
   * Return the column for the system period upper bound that will be included in findVersions() queries.
   *
   * @param tableAlias the table alias which will typically be 't0'
   * @param sysPeriod  the name of the sys_period column
   */
  String getSysPeriodUpper(String tableAlias, String sysPeriod);

}