CREATE DATABASE pharm
     CHARACTER SET cp1251
     COLLATE cp1251_general_ci;

 use pharm
Database changed
 create table pharm
     (id int,
     pharm_num int,
     address char(100),
     district  char(100),
     telephone int,
     PRIMARY KEY (id))
     ENGINE InnoDB CHARACTER SET cp1251;


create table drugs
     (drug_name char(15),
     id_drug int,
     producer char(25),
     price_one int,
     min_batch int,
     expiration_date int,
     PRIMARY KEY (id_drug))
     ENGINE InnoDB CHARACTER SET cp1251;


 create table zakaz
          (id_order int,
          data_completion date,
          id_client int,
          ID_DRUG INT,
      	  DRAG_NAME CHAR(15),
          ordered_batch int,
          put_batch int,
          privileges int,
          delivery_date date,
          PRIMARY KEY (id_order),
FOREIGN KEY (id_client) REFERENCES pharm (id)
ON DELETE RESTRICT ON UPDATE CASCADE, 
FOREIGN KEY (ID_DRUG) REFERENCES drugs (id_drug) 
ON DELETE RESTRICT ON UPDATE CASCADE)
ENGINE InnoDB CHARACTER SET cp1251;

ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`pharm`.`zakaz`, CONSTRAINT `zakaz_ibfk_1` FOREIGN KEY (`id_client`) REFERENCES `pharm` (`id`) ON UPDATE CASCADE)

FOREIGN KEY (ID_DRUG) REFERENCES drugs (id_drug)

 FOREIGN KEY (id_clienT) REFERENCES PHARM (id)

mysql>  ALTER TABLE ZAKAZ
    ->      ADD FOREIGN KEY (ID_DRUG) REFERENCES drugs (id_drug)
    ->      ON DELETE RESTRICT ON UPDATE CASCADE;
Query OK, 10 rows affected (0.41 sec)
Records: 10  Duplicates: 0  Warnings: 0

mysql> ALTER TABLE ZAKAZ
    ->      ADD FOREIGN KEY (id_clienT) REFERENCES PHARM (id)
    ->      ON DELETE RESTRICT ON UPDATE CASCADE;
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`pharm`.<result 2 when explaining filename '#sql-9b0_1'>, CONSTRAINT `#sql-9b0_1_ibfk_4` FOREIGN KEY (`id_client`) REFERENCES `pharm` (`id`) ON UPDATE CASCADE)
mysql>