sql - 如果不存在则删除表空间

Question

我已经编写了 pl/sql 脚本(有效，但看起来不太好):

DECLARE
   v_exists NUMBER;
BEGIN
   SELECT count(*) INTO v_exists FROM dba_tablespaces WHERE tablespace_name = 'hr_test';
   IF v_exists > 0 THEN
   BEGIN
      EXECUTE IMMEDIATE 'DROP TABLESPACE hr_test INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS';
   END;
   END IF;
   EXECUTE IMMEDIATE 'CREATE TABLESPACE hr_RJ DATAFILE ''E:\hr_test_01.dbf'' SIZE 16M';
END;

有没有办法在没有 EXECUTE IMMEDIATE 的情况下重写这个脚本？ ?

Answer 1

不可以。您不能在静态 PL/SQL 中发出 DDL 语句。

是的，将 native 动态 SQL 用于 DDL 目的是完全没问题的:

You need dynamic SQL in the following situations:

You want to execute a SQL data definition statement (such as CREATE), a data control statement (such as GRANT), or a session control statement (such as ALTER SESSION). In PL/SQL, such statements cannot be executed statically.

Oracle dynamic SQL