Drop Table 命令在 Oracle SQL 开发人员中不起作用，它不会在使用时删除现有的 table？

Question

drop Table countries;
drop Table regionss;

create TABLE regionss(
region_id NUMBER(3),
region_Name VARCHAR2(25),
CONSTRAINT regions_pk PRIMARY KEY(region_id)
);

create TABLE countriess(
country_id CHAR(2),
country_Name VARCHAR2(40),
region_id NUMBER(3),
CONSTRAINT countries_pk PRIMARY KEY(country_id),
CONSTRAINT regions_countries_fk FOREIGN KEY (region_id) REFERENCES regionss (region_id) 
);

我遇到了这些错误

Error starting at line : 4 in command -
create TABLE regionss(
region_id NUMBER(3),
region_Name VARCHAR2(25),
CONSTRAINT regions_pk PRIMARY KEY(region_id)
)
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 -  "name is already used by an existing object"
*Cause:    
*Action:

Error starting at line : 10 in command -
create TABLE countriess(
country_id CHAR(2),
country_Name VARCHAR2(40),
region_id NUMBER(3),
CONSTRAINT countries_pk PRIMARY KEY(country_id)
)
Error report -
ORA-00955: name is already used by an existing object
00955. 00000 -  "name is already used by an existing object"
*Cause:    
*Action:

Drop Command 的功能不是删除现有的 table 给它的吗？除非我更改我的 table 的名称，否则它不会工作，但是在更改名称后，当我第二次尝试运行代码时，它再次给我上面提到的错误。

Answer 1

这是因为您正在删除 table countries 并创建 table countriess。这会导致错误链：

你不能删除不存在的 table (countries)
regionss 存在，但它有外键（来自 coutriess）阻止它被删除。

SQL> drop Table countries;
drop Table countries
           *
ERROR at line 1:
ORA-00942: table or view does not exist


SQL> drop Table regionss;
drop Table regionss
           *
ERROR at line 1:
ORA-02449: unique/primary keys in table referenced by foreign keys

Drop Table 命令在 Oracle SQL 开发人员中不起作用，它不会在使用时删除现有的 table？

Drop Table command is not working in Oracle SQL developer, it is not dropping the existing table upon using?

sql

oracle

ddl

oracle-sqldeveloper