mysql - Error with creating table -

this statement, i'm getting error on customer_t. error states:

"01:22:05   drop table customer_t   error code: 1051. unknown table 'energyefficient.customer_t'    0.016 sec"  create table customer_t              (customerid   int               not null,               name         varchar(45)       not null,               address      varchar(256)              ,               email        varchar(100)              ,                   phone        varchar(16)               , constraint pk_customerid primary key (customerid));   create table order_t           (orderid            int        not null,                orderdate          date           null,                customerid         int        not null, constraint pk_orderid primary key (orderid), constraint fk_customerid foreign key (customerid) references customer_t(customerid));  create table equipment              (equipmentid         int        not null,               equipmenttype       varbinary(12)      ,               yearofmanufacture   int                ,               cost                decimal(9,2)       ,           maker               varchar(45)        ,           model               varchar(45)        ,           customerid          int                , constraint equipmentid_pk primary key (equipmentid), constraint customerid_fk foreign key (customerid) references customer_t(customerid));  create table order_line_t               (orderlineid        int        not null,               orderid             int        not null,               equipmentid         int        not null,               orderlinecost       decimal(9,2)       , constraint orderlineid_pk primary key (orderlineid), constraint orderid_fk1    foreign key (orderid) references order_t(orderid), constraint equipmentid_fk2 foreign key (equipmentid) references equipment_t(equipmentid));  create table maintenanceschedule_t              (maintenanceid       int         not null,               maintenancetype     varchar(45) not null,               schedule_date            date        not null,               equipmentid         int         not null,               serviceid           int                 , constraint maintenanceid_pk primary key (maintenanceid), constraint equipmentid_fk3 foreign key (equipmentid) references equipment(equipmentid));  create table service              (serviceid           int          not null,               estimatedcost       decimal(9,2) not null,               status              varchar(16)  not null,               servicedate         date                 ,               equipmentid         int          not null,               employeeid          int          not null,               actualcost          decimal(9,2)         ,               servicetype         varchar(45)  not null,               notes               varchar(2000)        ,  constraint serviceid_pk primary key (serviceid), constraint equipmentid_fk foreign key (equipmentid)  references equipment(equipmentid));  create table employee_t              (employeeid          int          not null,               annualsalary        decimal(9,2)         ,               name                varchar(45)  not null,               dob                 date                 ,               position            varchar(45)          , constraint employeeid_pk primary key (employeeid));   

try using this:

set foreign_key_checks=0; drop table energyefficient.customer_t; set foreign_key_checks=1;

some time needs set foreign key checks 0;

thanks