Re: how to check if a table exists? liu yingjiang January 05, 2008 09:48PM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily...
DROPTABLEIFEXISTStable_name; 1. 将table_name替换为您想要删除的表的名称。 重新检查表是否存在: SHOWTABLESLIKE'table_name'; 1. 将table_name替换为您想要检查的表的名称。 以上就是实现 “mysql drop table if exists” 的所有步骤。现在你应该知道如何使用这个语句来删除表了。 总结 在本文中,我们学习了...
由于使用了IF EXISTS选项,MySQL不会抛出错误,而是继续执行下面的语句。 序列图 下面是一个使用DROP TABLE语句和IF EXISTS选项的示例序列图: TableMySQLUserTableMySQLUseralt[Table exists][Table does not exist]DROP TABLE IF EXISTS customersCheck if table existsDelete table customersTable deleted successfullyTable...
使用IF NOT EXISTS命令判断是否添加字段 ALTER TABLE 表名 ADD COLUMN IF NOT EXISTS 列名 列数据类型 DEFAULT 默认值; IF NOT EXISTS这个参数用法就是让查询时若该列不存在,则自动添加,若存在则什么也不做。因此,运用此语句能够达到自动添加列的目的。
前段时间服务器蹦造成所有项目都启动不了,需要重装系统。而在重装前把数据及项目代码都打包备份。重装好后重新搭建项目,而在导入数据库时出现了个别数据表导不进,而后查看报错日志提示“Tablespace for table *** exists. Please DISCARD the table”。 解决
一般drop table if exists是数据库里面的，后面接表名，如：drop table if exists xxx_book 其意思是：如果数据库中存在xxx_book表，就把它从数据库中drop掉。备份sql中一般都有这样的语句，如果是数据库中有这个表，先drop掉，然后create表，然后再进行数据插入。拓展：数据库(Database)是按照数据...
Some pointers may be invalid and cause the dump to abort. Query (7f55ac0ca298): SELECT DISTINCT T.CUST_NO FROM testDB.TABLE_TRANSACTION T WHERE EXISTS (SELECT 1 FROM testDB.Table1 T1 WHERE T.CUST_NO = T1.CUST_NO ) AND T.AGENT_CERT_NO IS NOT NULL ...
Type '\c' to clear the current input statement. mysql> flush tables; Query OK, 0 rows affected (0.01 sec) mysql> create table t1(f1 int) engine=innodb; ERROR 1813 (HY000): Tablespace for table '`test`.`t1`' exists. Please DISCARD the tablespace before IMPORT. mysql> create table t1...
check vs. table existsence check.How to repeat:1. Create MySQL user that has no DROP privileges on the database level. 2. Using newly created account, run the following command: mysql> drop table if exists nosuchtable; ERROR 1142 (42000): DROP command denied to user 'newuser'@'...
Re: Check if a table exists kamiar kanani January 11, 2007 09:17AM Re: Check if a table exists --> here is a function to use. jeff maass July 19, 2008 05:12PM Sorry, you can't reply to this topic. It has been closed.