HibernateCriteria左連接OR子句

Question

我們的一個查詢存在問題，該查詢返回的是內部聯接而不是左聯接。 該查詢旨在檢索用戶具有顯式訪問權限的所有項目（該用戶所屬的用戶組之一被定義為項目“用戶”用戶組）或隱式操作（該項目未定義“用戶”用戶組） 。

相關代碼：

    // HibernateCriteria is a custom class that has junction, conjunction, disjunction objects (the ones from Hibernate)
    ICriteria criteriaInProjectUserGroup = new HibernateCriteria();
    criteriaInProjectUserGroup.addEqualTo(Project.USERGROUP+"." +UserGroup.USERGROUPASSOCIATIONS+"."+UserGroupAssociation.USEROID, user.getOid());
    ICriteria criteriaNoProjectUserGroup = CriteriaFactory.createCriteria();
    criteriaNoProjectUserGroup.addIsNull(Project.USERGROUP); 
    /*The join (criteriaIn...) must be added to the simple is null criteria (criteriaNo...),
     * to result in a right outer join, otherwise an inner join is created by ojb which returns 
     * an empty result set */
    criteriaNoProjectUserGroup.addOrCriteria(criteriaInProjectUserGroup);
    IQuery query = QueryFactory.createQueryByCriteria(ProjectBean.class, criteriaNoProjectUserGroup);        
    Collection projects = broker.getCollectionByQuery(query);

addEqualTo定義為：

public void addEqualTo(String attribute, Object value) {
    if (value!=null && value instanceof String && containsWildcards((String)value)) {
        addLike(attribute, value);
    }
    else {
        attribute = createAliasIfNecessary(attribute);
        conjunction.add(eq(attribute, value));
    }
}

addIsNull定義為：

public void addIsNull(String attribute) {
    attribute = createAliasIfNecessary(attribute);
    conjunction.add(isNull(attribute));
}

addOrCriteria定義為：

public void addOrCriteria(ICriteria criteria) {
    if(criteria instanceof HibernateCriteria) {
        HibernateCriteria subCriteria = (HibernateCriteria) criteria;
        Junction subJunction = subCriteria.resolveJunction();
        if(disjunction == null ) {
            disjunction = disjunction();
        }
        disjunction.add(subJunction);
        aliasNameSet.addAll(subCriteria.aliasNameSet);
    }
}

resolveJunction定義為：

private Junction resolveJunction() {
    if(junction == null) {
        if(disjunction == null) { // no 'or' subcriteria have been added
            junction = conjunction; // then the main junction is simply the conjunction
        } else {
            // disjunction != null means an 'or' subcriteria has been already added.
            // then the main junction is disjunction with a conjunction as an operand
            junction = disjunction;
            junction.add(conjunction);
        }
    }
    return junction;
}

getCollectionByQuery將該條件提取到org.hibernate.criterion.DetachedCriteria對象中：

    try {
        DetachedCriteria detachedCriteria = DetachedCriteria.forClass(clazz);
        // create aliases if necessary
        Set<String> createdAliasSet = new HashSet<String>();
        for(String aliasAssociationPath: aliasNameSet) {
            String[] nestedPropertiesArray = aliasAssociationPath.split("\\.");
            String previousNestedProperty = null;
            for(String nestedProperty: nestedPropertiesArray) {
                String currentAliasName = 
                    (previousNestedProperty == null ? nestedProperty : previousNestedProperty + "_" + nestedProperty);
                if(!createdAliasSet.contains(currentAliasName)) {
                    String currentAssociationPath = 
                        (previousNestedProperty == null ? nestedProperty : previousNestedProperty + "." + nestedProperty);
                    detachedCriteria.createAlias(currentAssociationPath, currentAliasName);
                    createdAliasSet.add(currentAliasName);
                }
                previousNestedProperty = currentAliasName;
            }
        }
        detachedCriteria.add(resolveJunction());
        return detachedCriteria;
    } catch (HibernateException e) {
        throw new PersistenceBrokerException(e);
    } 

然后將其轉換為org.hibernate.Criteria對象，並在該函數上調用Criteria.list（）。

產生的Mysql查詢為：

select
    this_.oid as oid1_41_2_,
    this_.archived as archived2_41_2_,
    this_.archivedDateTime as archived3_41_2_,
    this_.version as version4_41_2_,
    this_.adminGroupOid as adminGro5_41_2_,
    this_.buildScript as buildScr6_41_2_,
    this_.buildToolType as buildToo7_41_2_,
    this_.deployScript as deploySc8_41_2_,
    this_.deployToolType as deployTo9_41_2_,
    this_.description as descrip10_41_2_,
    this_.issueTrackingSystemOid as issueTr11_41_2_,
    this_.locked as locked12_41_2_,
    this_.name as name13_41_2_,
    this_.projectType as project14_41_2_,
    this_.testScript as testScr15_41_2_,
    this_.testToolType as testToo16_41_2_,
    this_.userGroupOid as userGro17_41_2_,
    this_.vcrOid as vcrOid18_41_2_,
    this_.vcrProjectName as vcrProj19_41_2_,
    usergroup1_.oid as oid1_65_0_,
    usergroup1_.archived as archived2_65_0_,
    usergroup1_.archivedDateTime as archived3_65_0_,
    usergroup1_.version as version4_65_0_,
    usergroup1_.description as descript5_65_0_,
    usergroup1_.name as name6_65_0_,
    usergroup1_.type as type7_65_0_,
    usergroup_2_.oid as oid1_58_1_,
    usergroup_2_.archived as archived2_58_1_,
    usergroup_2_.archivedDateTime as archived3_58_1_,
    usergroup_2_.version as version4_58_1_,
    usergroup_2_.scmUserOid as scmUserO6_58_1_,
    usergroup_2_.userGroupOid as userGrou5_58_1_ 
from
    .PROJECT this_ 
inner join
    .USERGROUP usergroup1_ 
        on this_.userGroupOid=usergroup1_.oid 
inner join
    .SCMUSER_USERGROUP usergroup_2_ 
        on usergroup1_.oid=usergroup_2_.userGroupOid 
where
    (
        (
            usergroup_2_.scmUserOid=3
        ) 
        or (
            this_.userGroupOid is null
        )
    )

問題在於，這只是返回具有相關UserGroup的項目，因為它是內部聯接。 這意味着沒有定義用戶組就無法獲得項目。

我發現解決此問題的方法是對兩個聯接都使用左外部聯接，但是我不知道該如何進行工作。 問題是我不能碰到addX方法，因為這些方法在服務類中的任何地方都絕對使用。

如何調整此代碼，以使生成的SQL使用左外部聯接而不是內部聯接？

Answer 1

經過更多研究后，我發現解決此問題的正確方法是在createAlias（）中添加joinType：

 detachedCriteria.createAlias(currentAssociationPath, currentAliasName, JoinType.LEFT_OUTER_JOIN);

但是，這是一個相當復雜的修復程序，因為目前沒有使用joinType參數的地方，這意味着我需要與更多高級開發人員進一步討論。 現在，我將使用單獨的查詢來檢索顯式和隱式訪問權限，並在Java中將它們連接在一起。