mybatis|mybatis createcriteria和or的区别说明

createcriteria和or的区别 mybatis generator插件生成的example中,有createcriteria和or方法,他们有什么区别呢?
通过源码,能很清楚的看出差别
createcriteria,当没有规则时,则加入到现有规则,但有规则时,不再加入到现有规则,只是返回创建的规则

public Criteria createCriteria() {Criteria criteria = createCriteriaInternal(); if (oredCriteria.size() == 0) {oredCriteria.add(criteria); }return criteria; }

or,创建的规则,加入到规则集中,并且是or的关系
public Criteria or() {Criteria criteria = createCriteriaInternal(); oredCriteria.add(criteria); return criteria; }

mybatis中Example的and和or 【mybatis|mybatis createcriteria和or的区别说明】能用Example代码解决的,我都不会去写个SQL放在项目里。我希望让代码尽量优雅、易读,所以这里记录一下关于MyBatis中Example的and和or的使用,主要是如下两种场景:
  • where (条件1 and 条件2) or (条件3 and 条件4)
  • where (条件1 and 条件2) and (条件3 or 条件4)
where (条件1 and 条件2) or (条件3 and 条件4)
//条件1 and 条件2example.createCriteria().andEqualTo("isDeleted",IsDeleted.NOT_DELETED).andEqualTo("name", projectCatalogEntity.getName()); //or (条件3 and 条件4)example.or(example.createCriteria().andEqualTo("isDeleted",IsDeleted.NOT_DELETED).andEqualTo("code", projectCatalogEntity.getCode()));

WHERE ( is_deleted = ? and name = ? ) or ( is_deleted = ? and code = ? )
where (条件1 and 条件2) and (条件3 or 条件4)
//条件1 and 条件2example.createCriteria().andEqualTo("isDeleted",IsDeleted.NOT_DELETED)).andEqualTo("parentId", projectCatalogEntity.getParentId()); //and (条件3 or 条件4)example.and(example.createCriteria().andEqualTo("name", projectCatalogEntity.getName()).orEqualTo("code", projectCatalogEntity.getCode()));

WHERE ( is_deleted = ? and parent_id = ? ) and ( name = ? or code = ? )
以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。

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