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package com.cloud.utils.db;
/**
* SearchBuilder is meant as a static query construct. Often times in DAO code,
* we write static sql that just assumes the database table does not change.
* change by hand. SearchBuilder is meant to replace that. It provides load-time
*
* 1. SearchBuilder is declared as final because it should not change after load time.
* 2. search.entity().getHostId() allows you to declare which field you are searching
* on. By doing this, we take advantage of the compiler to check that we
* are not searching on obsolete fields. You should try to use this
* as much as possible as oppose to the addAndByField() and addOrByField() methods.
* 3. Note that the same SearchBuilder is used to create multiple SearchCriteria.
* This is equivalent to clearing the parameters on PreparedStatement. The
* multiple SearchCriteria does not interfere with each other.
* 4. Note that the same field (getHostId()) was specified with two param
* names. This is basically allowing you to reuse the same field in two
* parts of the search.
*
* {@code
* final SearchBuilder<UserVmVO> search = _userVmDao.createSearchBuilder();
* final String param1 = "param1";
* final String param2 = "param2";
* search.addAnd(param1, search.entity().getHostId(), SearchCriteria.Op.NEQ);
* search.addAnd(param2, search.entity().getHostId(), SearchCriteria.op.GT);
* ...
* SearchCriteria sc = search.create();
* sc.setParameters(param1, 3);
* sc.setParameters(param2, 1);
*
* ...
*
* SearchCriteria sc2 = search.create();
* sc2.setParameters(param1, 4);
* sc2.setParameters(param2, 1);
* }
*
* @param <T> VO object.
*/
public class SearchBuilder<T> extends GenericSearchBuilder<T, T> {
public SearchBuilder(Class<T> entityType) {
super(entityType, entityType);
}
}