Why Freeradius and Mysql dont work?

["yao guoxian" <yaoguoxian@gmail.com>]

   Platform and Environment:
   Freeradius:1.0.5  on Redhat 9
   MySQL:MySQL-standard-5.0.20-linux-i686
   Step:
   1. create database radius;
   2.mysql -uroot -prootpass radius < db_mysql.sql ;
   3.Edit radiusd.conf and sql.conf;
   Debug Result:   
   Nothing to do.  Sleeping until we see a request.
rad_recv: Access-Request packet from host 
202.117.7.223:1490, id=6, length=47
        User-Name = "barney"
        CHAP-Password = 0xad35a90d409c25b78b6d148a531358d9ac
  Processing the authorize section of radiusd.conf
modcall: entering group authorize for request 2
  modcall[authorize]: module "preprocess" returns ok for request 2
  rlm_chap: Setting 'Auth-Type := CHAP'
  modcall[authorize]: module "chap" returns ok for request 2
  modcall[authorize]: module "mschap" returns noop for request 2
    rlm_realm: No '@' in User-Name = "barney", looking up realm NULL
    rlm_realm: No such realm "NULL"
  modcall[authorize]: module "suffix" returns noop for request 2
radius_xlat:  'barney'
rlm_sql (sql): sql_set_user escaped user --> 'barney'
radius_xlat:  'SELECT id, UserName, Attribute, Value, op           FROM radcheck           WHERE Username = 'barney'           ORDER BY id'
rlm_sql (sql): Ignoring unconnected handle 4..
rlm_sql (sql): Ignoring unconnected handle 3..
rlm_sql (sql): Ignoring unconnected handle 2..
rlm_sql (sql): Ignoring unconnected handle 1..
rlm_sql (sql): Ignoring unconnected handle 0..
rlm_sql (sql): There are no DB handles to use! skipped 5, tried to connect 0
  modcall[authorize]: module "sql" returns fail for request 2
modcall: group authorize returns fail for request 2
Finished request 2
Going to the next request
--- Walking the entire request list ---
Waking up in 6 seconds...
rad_recv: Access-Request packet from host 202.117.7.223:1490, id=6, length=47
Discarding duplicate request from client liv1:1490 - ID: 6
--- Walking the entire request list ---
Waking up in 2 seconds...
--- Walking the entire request list ---
Cleaning up request 2 ID 6 with timestamp 45bca7cb
Nothing to do.  Sleeping until we see a request.
   
   From the above results, I guess mysql doesnt work. But I can access databases from the command line .The Freeradius Server worked well when I use the "user", not using MySQL.
  Any suggestion?