方法三、 Alternatively, you canuseSHOW TABLES SHOW TABLESLIKE'yourtable';Ifthereisa rowinthe resultset,tableexists. 个人觉得方法三很不错 FROM:http://stackoverflow.com/questions/8829102/mysql-check-if-table-exists-without-using-select-from#8829109...
方法三、 Alternatively, you canuseSHOW TABLES SHOW TABLESLIKE'yourtable';Ifthereisa rowinthe resultset,tableexists. 个人觉得方法三很不错 FROM:http://stackoverflow.com/questions/8829102/mysql-check-if-table-exists-without-using-select-from#8829109...
下面是一个示例代码,用于判断名为users的表是否存在: importmysql.connectordefcheck_table_exists():conn=mysql.connector.connect(host="localhost",user="root",passwd="password",database="mydatabase")cursor=conn.cursor()cursor.execute("SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE table_schema ...
Date: January 11, 2007 09:17AM use this command: mysql> show tables like 'your_table_name'; in your c program you can check: if(row_count==1) /* then table exists; */ Sorry, you can't reply to this topic. It has been closed. ...
语法格式:alter table 表名 drop primary key; 例:删除books3表的bookname字段的主键约束。 2. 复合主键 复合主键指主键由多个字段组成。 ①创建表时指定复合主键 其语法格式为为:primary key (字段名1,字段名2,...字段名n); 例:创建books5表,设置product_id,region_code为复合主键。 ②...
1.7 CHECK约束(了解) MySQL使用时不报错,但忽略该约束: createtableuser_test(idint,namevarchar(20),sexvarchar(1),check(sex='男'orsex='女')); 2. 表的设计 2.1 一对一 2.2 一对多 2.3 多对多 多对多的关系两者之间的对应关系是非常复杂的. ...
drop tableifexists t_user;create tablet_user(id int primary key*auto_increment*,// id字段自动维护一个自增的数字,从1开始,以1递增。usernamevarchar(255)); 外键约束:foreign key 外键主要是维护表之间的关系的,主要是为了保证参照完整性,如果表中的某个字段为外键 字段,那么该字段的值必须来源于参照的表...
$check = mysql_query("CREATE TABLE IF NOT EXISTS ".$testname." ( id INT, user VARCHAR(30), questn VARCHAR(30), ans VARCHAR(30))"); mysql_query ("INSERT IG 浏览1提问于2014-03-31得票数 2 3回答 如何检查一个表到另一个表的id? 、、 如何使用php查找一个表的不同值id是否退出到另...
共分为not null, unique, default, primary key, check这几种 null约束 定义:指示某列不能存储null值 在创建表时,就是指定某列不为空,当指定列插入null会报错 -- 重新设置学生表结构 DROP TABLE IF EXISTS student;CREATE TABLE student (id INT NOT NULL ,sn INT ,name VARCHAR ( 20 ),qq_mail VARCHAR...
I want to check for the existance of a table in a Stored procedure, and I need some function that will return 0 or 1 if the table exists or not, and I have hard time locating one in the documentation, someting that will work in the folowing code: ...