mysql里查询时怎么把一张表里的上级ID显示为上级名称？

select t1.*,t2.deptname as 新的名字

from t_dept t1 left join t_dept t2 on t1.sjid=t2.deptid

这样写比较靠谱。不能直接显示

java版的实际例子。类同你说的情况

private void findChildList(AssetType parent,List<AssetType>list){

String hql = "from AssetType a where a.parentAssetType.assetTypeId=? ORDER BY a.sort,a.assetTypeName asc"

List<AssetType>childList = this.assetTypeDao

.getEntityManager()

.createQuery(hql)

.setParameter(1, parent.getAssetTypeId())

.getResultList()

int size = childList.size()

if(size>0){

for (int i = 0i <sizei++) {

AssetType assetType = childList.get(i)

List<AssetType>childs = assetType.getChildAssetType()

if(childs.size()>0){

list.addAll(childs)

this.findChildList(assetType, list)//递归查询节点的子节点

}

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