在drop table时,Oracle中没有类似MySQL和PostgreSQL中的"IF EXISTS"选项,但可以通过存过实现:
CREATE OR REPLACE PROCEDURE prc_dropifexists(p_owner varchar2, p_table varchar2)
AS
v_count varchar2(5);
BEGIN
SELECT COUNT(*) INTO v_count FROM dba_tables t
WHERE t.owner = p_owner
AND t.table_name = p_table;
IF v_count > 0 THEN
EXECUTE IMMEDIATE 'drop table '||p_owner||'.'||p_table||' purge';
END IF;
END prc_dropifexists;