In MySQL it is pretty easy to drop a table if it exists already. In Oracle and Microsoft’s SQL Server it is a little more complicated. Today I want to present you the solutions for these two DBMS’. MySQL: DROP TABLE IF EXISTS [table_name] Oracle: BEGIN EXECUTE IMMEDIATE 'DROP TABLE...
CREATETABLEtest_1(c1VARCHAR2(50));CREATETABLEtest_2(c1VARCHAR2(50));CREATETABLEtest_3(c1VARCHAR2(50));Code language:SQL (Structured Query Language)(sql) Then, execute the PL/SQL block above. In this tutorial, you have learned how to use the OracleDROP TABLEstatement to drop a table fr...
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; ...
Oracle Database/ Release 12.2 SQL言語リファレンス 目的 DROPTABLE文を使用すると、表またはオブジェクト表をごみ箱に移動したり、表およびそれに含まれるすべてのデータをデータベースから完全に削除することができます。 ノート: PURGE句を指定しないかぎり、DROPTABLEを実行しても、他のオブジ...
create table toys_clone as select * from toys;Easy, right?Yes. But, as always, there's more to it than this. You'll want to add some constraints to your table. And there are many types of table available in Oracle Database, including:Table...
SQL> drop table dept; drop table dept * ERROR at line 1: ORA-02449: unique/primary keys in table referenced by foreign keys SQL> SQL> drop table dept cascade constraints; Table dropped. How to drop multiple tables in oracle There might be a requirement to drop multiple tables in a singl...
Posted in ORACLETagged advantages of global temporary table in oracle, alter global temporary table, delete global temporary table in oracle, how to check global temporary table in oracle, how to drop global temporary table in oracle, ora-14452 drop global temporary table, ora-14452 while ...
309 310 你可以在单个的 ALTER TABLE 语句中发出多个 ADD、ALTER、DROP 和CHANGE 子句。这是 MySQL 对 ANSI SQL92 的扩展,ANSI SQL92 只允许在每个 ALTER TABLE 语句中一个子句。 311 312 CHANGE col_name、DROP col_name 和 DROP INDEX 是MySQL 对 ANSI SQL92 的扩展。 313 314 MODIFY is an Oracle ...
DROP TABLE文を実行するとすぐに、ユーザーは削除された表またはそのデータにアクセスできなくなります。DROP TABLE文を実行すると、すべての表データの削除がバックグラウンドで非同期に行われます。 特定のリージョンのMR表を削除しても、MR表は引き続き他の関連リージョンに残ります。特定...