使用update在对mysql数据表进行数据更新的时候,出了问题
我的语句sql语句是
sql="update users set user_name="+name+"where user_id="+id+"";name和id都是String 类型的变量程序报异常如下:com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user_id=33' at line 1看不懂这句话,请大家帮帮忙
我的语句sql语句是
sql="update users set user_name="+name+"where user_id="+id+"";name和id都是String 类型的变量程序报异常如下:com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user_id=33' at line 1看不懂这句话,请大家帮帮忙
user_name和user_id都是字符串吧?至少user_name是字符串吧?而且你where之前还没有空格。sql="update users set user_name='"+name+"' where user_id='"+id+"'";
看着的话应该是username="+username少空格,而且username应该是String类型吧?sql语句里得用单引号引吧,后面id也没有空格,在最后你加一空串干啥啊?
'user_id=33'
String id="zhangsan001";
String sql="update users set user_name="+name+"where user_id="+id+"";
System.out.println(sql); 打印结果为:
update users set user_name=张三where user_id=zhangsan001
很明显:
sql语句这样写才对
String sql="update users set user_name="'+name+"' where user_id='"+id+"'";
在控制台输出来看看,然后在数据库执行下就知道错误在哪里了。
sql="update users set user_name = '"+name+"' where user_id = '"+id+"'";