修改ER图和DDL语言

code/database/ddl.sql

@@ -2,7 +2,6 @@ create table T_Drugs(
     ID          varchar(5),
     name        varchar(20),
     num         numeric(3,0),
-    unit_price  numeric(5,2),
     
     primary key (ID));
     
@@ -51,6 +50,7 @@ create table T_Department(
 create table T_Type(
     d_id    varchar(5),
     n_id    varchar(5),
+    price   numeric(5,2),
     
     primary key (d_id),
     foreign key (d_id) references T_Drugs(ID),