有两个表:user和meta
user 字段有ID ,username
meta字段有 userid , key ,value
----------------------------------------------user表数据
ID           username
1                  姓名1
2                  姓名2
------------------------------------------------
meta表数据
userid              key                    value
1                     dlcs                       1
1                      vp                          是
2                      dlcs                      3
2                      vp                          否
-------------------------------------------------------------------
如何生成以下表
ID                         username               dlcs           vp
1                            姓名1                     1               是
2                            姓名2                    3                否