SQL> drop table t; drop table t * ERROR at line 1: ORA-02449: unique/primary keys in table referenced by foreign keys (违反了constraint,员工销售表t1有參照到table t,这个reference relation不允许你drop table t) SQL> drop table t cascade constraints; Table dropped. SQL> select * from t1; ...
SQL> drop table t; drop table t * ERROR at line 1: ORA-02449: unique/primary keys in table referenced by foreign keys (违反了constraint,员工销售表t1有參照到table t,这个reference relation不允许你drop table t) SQL> drop table t cascade constraints; Table dropped. SQL> select * from t1; ...
SQL> 我们可以发现利用Drop table cascade constraints可以以刪除关联table t的constraint來达成你drop table t的目的,原來属于t1的foreign key constraint已经跟随着被删除掉了,但是,储存在table t1的资料可不会被删除,也就是说Drop table cascade constraints是不影响到存储于objec里的row data。
使用PL/SQL块删除名称以TEST_开头的所有表。 BEGINFORrecIN(SELECTtable_nameFROMall_tablesWHEREtable_nameLIKE'TEST_%') LOOPEXECUTEimmediate'DROP TABLE'||rec.table_name||'CASCADE CONSTRAINTS';ENDLOOP;END;/--该符号表示执行这段PL/SQL代码 注意:如果在PLSQL Developer工具内执行以上语句时,出现ORA-06550 P...
一个极简单的例子,例如你有一个员工基本资料表,上面可能有员工编号和员工姓名等字段,另外有一个员工销售表,上面有员工编号和员工销售额两个字段,员工薪资表的员工编号字段为一个 foreign key 参照到员工基本资料表的员工编号: SQL> drop table t; Table dropped. SQL> drop table t1 ; Table dropped. SQL> ...
SQL> select CONSTRAINT_NAME,TABLE_NAME from dba_constraintswhere owner = 'SYS' and TABLE_NAME = 'B' ; no rows selected 利用Drop tablecascadeconstraints可以删除从表的constraint,从而可实现drop table A。原属于B的foreign key constraint已经跟随着被删除掉了,但是,储存在table B中的记录不会被删除,也...
DROPTABLEschema_name.table_name [CASCADECONSTRAINTS|PURGE];Code language:SQL (Structured Query Language)(sql) In this statement: First, indicate the table and its schema that you want to drop after theDROP TABLEclause. If you don’t specify the schema name explicitly, the statement assumes that...
1. 使用SQL语句来删除所有表: ```sql BEGIN FOR cur_rec IN (SELECT object_name FROM user_objects WHERE object_type = 'TABLE') LOOP EXECUTE IMMEDIATE 'DROP TABLE ' || cur_rec.object_name || ' CASCADE CONSTRAINTS'; END LOOP; END; ``` 这个SQL语句会遍历数据库中所有的表,并逐个删除它们。
The syntax for the OracleDROP TABLE statementis: DROP TABLE [schema_name].table_name [ CASCADE CONSTRAINTS ] [ PURGE ]; Parameters or Arguments schema_name The name of the schema that owns the table. table_name The name of the table to remove from the Oracle database. ...
2、在drop时加上purge选项:drop table 表名 purge,该选项也可以通过删除recyclebin区域来永久性删除表。 删除表: SQL>drop table emp cascade constraints; SQL>purge table emp; 删除当前用户的回收站: SQL>purge recyclebin; 删除全体用户在回收站的数据: ...