删除DB2实例下的数据库
db2ilist 查看所有实例 
db2 get instance 查看当前连接的实例
db2 list db directory 查看当前实例下连接的数据库========================================
C:\\Users\\Administrator>db2 list database directory --查看当前实例下连接的数据库 System Database Directory
 Number of entries in the directory = 2Database 1 entry:
 Database alias                       = TEST123 Database name                        = TEST123 Local database directory             = C: Database release level               = d.00 Comment                              =
 Directory entry type                 = Indirect Catalog database partition number    = 0 Alternate server hostname            =
 Alternate server port number         =  Database 2 entry:
 Database alias                       = SAMPLE Database name                        = SAMPLE Local database directory             = C: Database release level               = d.00 Comment                              =
 Directory entry type                 = Indirect Catalog database partition number    = 0 Alternate server hostname            = Alternate server port number         =
C:\\Users\\Administrator>db2 connect to test123 --连接到需要删除的数据库   Database Connection Information
 Database server        = DB2/NT 9.7.11 SQL authorization ID   = DB2ADMIN Local database alias   = TEST123
C:\\Users\\Administrator>db2 list applications  --查看当前数据库的连接情况Auth Id  Application    Appl.      Application Id                  DB       # of         Name           Handle                  Name    Agents
-------- -------------- ---------- ------------------------------------------------------- -------- -----DB2ADMIN javaw.exe      19233      *LOCAL.DB2.191023053134                  SAMPLE   1
DB2ADMIN javaw.exe      19245      *LOCAL.DB2.191023053146                  SAMPLE   1
DB2ADMIN db2bp.exe      19250      *LOCAL.DB2.191023053151                  TEST123  1
C:\\Users\\Administrator> 
C:\\Users\\Administrator>db2 connect reset  --断开所有连接DB20000I  The SQL command completed successfully.
C:\\Users\\Administrator>db2 drop database test123  --删除数据库
DB20000I  The DROP DATABASE command completed successfully.C:\\Users\\Administrator>