mysql-error-1064

hi every one i was reading a sans book about blind sql injection the author of the book mention that if you want to trigger an error in mysql use this query and inject it in the target 1 and (select 1 from (select count(*),concat(/*your malicious query here*/,floor(rand(0)*2)x from users group by x) a) and he says (author) that count(*) on a group by "floor(rand(0)*2)" causes a duplicate key in internal table and display the key My questions: first why he put the x there ? second what is duplicate key in internal table error and what query causes it other then this one and how count(*) on a

I have a problem with mysql table while try to insert values in database. I followed this tutorial http://sqllessons.com/categories.html and created table like the table from tutorial table code create table categories ( id integer not null primary key , name varchar(37) not null , parentid integer null , foreign key parentid_fk (parentid) references categories (id) ); error SQL query: Edit Edit INSERT INTO `mydb`.`categories` ( `id` , `name` , `parentid` ) VALUES ( '', 'groceries', NULL ), ( '', 'snacks', NULL ) MySQL said: Documentation #1062 - Duplicate entry '0' for key 'PRIMARY' Help me

This seems stupidly easy but I'm stuck with a simple insert statement.See below: begin work; CREATE TEMPORARY TABLE IF NOT EXISTS insert_table AS ( select r.resource_id ,fr.file_repos_id ,mv.VALUE from resources r join versions v on v.RESOURCE_ID = r.resource_id join metadata_values mv on mv.resource_id = r.resource_id join file_repository fr on fr.file_repos_id = v.foreign_id where v.version_status = 'C' and r.RESOURCE_TYPE = 4 and fr.file_title in ('suburbs') ); insert into metadata_values (elem_id,value,resource_type,resource_id,foreign_id,mtvr_id,mett_id) values (62,'test',4,insert_table

In my Yii application, I have a model that represents siteconfig table and have four columns: integer config_id , string key , string value , string update_time . I created a model using Gii (to ensure that I will not make any mistakes). I don't publish entire code here, cause this is 100% unmodified by me, standard model code generated by Gii. Since my problem is related to search, I only publish important part of generated code (the search() method): public function search() { // Warning: Please modify the following code to remove attributes that // should not be searched. $criteria=new

I have problems with MySQL on my MacBook. I had updated my OS from Yosemite to El Capitan before I installed MySQL server. Now, when I try to run MySQL on Terminal, I got the error like this ERROR! The server quit without updating PID file Anyone can help me please? Thanks a lot! Try updating your my.cnf file to set the location of the PID file manually. Here's how you do that. In your Terminal run the following command. ps -ax | grep mysql This will list all the locations of the important mysql files. Look for the path of the --pid-file I will look something like this: --pid-file=/path/to