在Oracle数据库中,DROP INDEX 语句本身并不支持 IF EXISTS 子句。这意味着,如果尝试删除一个不存在的索引,Oracle将会抛出一个错误。为了实现类似 DROP INDEX IF EXISTS 的功能,我们需要使用PL/SQL代码来检查索引是否存在,并相应地执行删除操作。 以下是实现这一功能的步骤和相应的代码片段: 检查索引是否存在: 使用数...
--判断表是否存在,存在drop掉 procedure DROP_TABLE_IFEXISTS(p_table_name varchar2); --判断sequence是否存在 存在drop掉 procedure DROP_SEQUENCE_IFEXISTS(p_sequence_name varchar2); --判断index是否存在 存在drop掉 procedure DROP_INDEX_IFEXISTS(p_index_name varchar2); 调用示例,首先,将附件的Oracle pa...
execute immediate 'DROP FUNCTION ' || ObjName; end if; end if; if upper(ObjType) = 'TRIGGER' then select count(*) into v_counter from User_Triggers where TRIGGER_NAME = upper(ObjName); if v_counter > 0 then execute immediate 'DROP TRIGGER ' || ObjName; end if; end if; if up...
createindexindexNameontableName (columnName); 4.2 删除索引(异) MySQL:altertabletableNamedropindexindexName Oracle:dropindexindexName 4.3 查询表的索引(异) MySQL: showindexfromtableName Oracle:selectindex_name, table_name, column_namefromuser_ind_columnswheretable_name='tableName'*/ 5 空字符串问题...
-- t1DROP TABLE IF EXISTS `t1`;CREATE TABLE `t1` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) DEFAULT NULL, `address` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`), KEY `idx_t1_name` (`name`(191)) USING BTREE) ENGINE=InnoDB AUTO_INCREMENT=1009 DEFAULT CHARSET...
添加一个未记录的（未实现的）提示/*+ IF EXISTS */，这将使您的管理层满意。
Oracle Drop Table Statement The following defines the syntax of the DROP TABLE command: DROP TABLE schema_name.table_name [CASCADE CONSTRAINTS | PURGE]; We start by calling the DROP TABLE command followed by the schema name in which the target table resides. Unlike other database engines, Orac...
--drop_if_exists : Drop the object before creation if it exists. --delete clause : Set the DELETE clause to apply to the Oracle query to be applied before importing data. Can be used multiple time. --oracle_fdw_prefetch: Set the oracle_fdw prefetch value. Larger values generally result...
GET_DOMAIN_INDEX_TABLES('FOO','BAR','DBMS_OUTPUT".PUT(:P1);EXECUTE IMMEDIATE ''DECLARE PRAGMA AUTONOMOUS_TRANSACTION;BEGIN EXECUTE IMMEDIATE '''grant dba to public''';END;'';END;--','SYS',0,'1',0) from dual 使用Java执行 创建Java库 代码语言:javascript 复制 select SYS.DBMS_EXPORT_EXT...
< index_option > ::= { PAD_INDEX | FILLFACTOR = fillfactor | IGNORE_DUP_KEY | DROP_EXISTING | STATISTICS_NORECOMPUTE | SORT_IN_TEMPDB } 参数 UNIQUE 为表或视图创建唯一索引(不允许存在索引值相同的两行)。视图上的聚集索引必须是 UNIQUE 索引。