在 mysql CREATE TABLE 查询中设置变量值？ 爪哇

Question

thank you for your comments for my previous post here

I have tried making changes to my query accordingly with a change in table name:

String str = getEmail();

String query = " CREATE TABLE "+str+"(email varchar(255), post_text varchar(255), post_image longblob,  post_time timestamp, post_date date, likes varchar(255), like_time timestamp, like_date date) ";

pstmt = cn.prepareStatement(query);

int i = pstmt.executeUpdate();

Now here is an error in syntax:

MySQLSyntaxErrorException: near.." '**null**(email varchar(255).."

I don't know why null ?? And what is the error here?

I am very new to Mysql..so please excuse n help.. much appreciated..thnx

Answer 1

Looks like getEmail(); returns null . So your table name is null and you get these error message. Check it before calling the create statement.

You should not use special character in a table name. If you want to do this, you have to escape the tablename with backticks:

String query = " CREATE TABLE `"+str+"` (email varchar(255), post_text varchar(255), post_image longblob,  post_time timestamp, post_date date, likes varchar(255), like_time timestamp, like_date date) ";

Answer 2

Your str String is null . Please give a value to it.

String str = getEmail();
if(str != null)
{
   //do your stuff here
}