Question

mysql怎么查询树形结构的所有上级

一个表 有id和pid 是树形结构 给定一个或者一组id 查询出所有的上级 跪求 在线等。。急。。

Answer 1

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 = 0; i < size; i++) {
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
}
}
}
}