mysql

mysql subquery strangely slow

I have a query to select from another sub-query select. While the two queries look almost the same the second query (in this sample) runs much slower: SELECT user.id ,user.first_name -- user.* FROM user WHERE user.id IN (SELECT ref_id FROM education WHERE ref_type='user' ...

change password code error

I've created a code to change a password. Now it seem contain an error. When I fill in the form to change password, and click save the error message: Warning: mysql_real_escape_string() expects parameter 2 to be resource, null given in C:\Program Files\xampp\htdocs\e-Complaint(FYP)\userChangePass.php on line 103 Warning: mysql_r...

how to delete duplicates in mysql using case

Right now I am using something like this to delete duplicates in mysql table : delete t2 from my_table1 as t1, my_table1 as t2 where t1.TestCase = t2.TestCase and t2.id > t1.id; say I have a structure like this : ID TestCAse Result 1 T1 PASS 2 T2 FAIL 3 T3 FAIL 4 T3 PASS now, in the above case T3 ...

where has sun mysql database manager gone???

If I recall correctly, there where at least to desktop programas from sun which were very useful for handling mysql databases... Now, all I can find is some mysql workbench which is only useful for designing data... Both programs I'm talking about allowed you to manage servers, create database, create tables, index, perform querys, edi...

SELECT(IF(IN query.

There are 3 tables. Products, Options and Prod_Opts_relations. The latter holds product_id and option_id so i should be able to figure out which options are selected for any given product. Now i want to retrieve all options from the options table where the value of an extra alias field should hold checked or unchecked depending on the e...

User sumbitted top 5 and sort by popularity

Hi, Database setup (MySQL) table: top_fives id, uid, first, second, third, fourth, fifth, creation_date 1, 1, cheese, eggs, ham, bacon, ketchup, 2010-03-17 2, 2, mayonaise, cheese, ketchup, eggs, bacon, 2010-03-17 Users can submit their top 5 of a certain subject. Now I would like a summary of the top fiv...

Grant permissions to a set of databases matching a pattern in MysQL 5.0

I'm lead to understand that the following grants all proveleges to all databases that name begin with 'xian_', but mysql complains about a syntax error near ''xian_... GRANT ALL PRIVILEGES ON 'xian_%.*' TO xian@'192.168.1.%'; What is the correct syntax? Am I right in thinking that the _ needs escaping to \_ too as it is also a wildcard...

Using * in SELECT Query

I am currently porting an application written in MySQL3 and PHP4 to MySQL5 and PHP5. On analysis I found several SQL queries which uses "select * from tablename" even if only one column(field) is processed in PHP. The table has almost 60 columns and it has a primary key. In most cases, the only column used is id which is the primary ke...

MySQL Search Query on two different fields

I need to search on two fields using LIKE function and should match also in reverse order. My table uses InnoDB which dont have Full text search. Consider the following case: I have users table with first_name and last_name column. On it, there is a row with the following value: { first_name: 'Ludwig', last_name: 'van Beethove...

INSERT ... ON DUPLICATE KEY UPDATE with WHERE?

Hi! I'm doing a INSERT ... ON DUPLICATE KEY UPDATE but I need the update part to be conditional, only doing the update if some extra condition has changed. However, WHERE is not allowed on this UPDATE. Is there any workaround for this? I can't do combinations of INSERT/UPDATE/SELECT since this needs to work over a replication. ...

How should I structure my settings table with mysql?

I want to use MySQL to store a bunch of admin settings - what's the best way to structure the table? Like this? Setting _|_ Value setting1 | a setting2 | b setting3 | c setting4 | d setting5 | e Or like this? |--------|_setting1_|_setting2_|_setting3_|_setting4_|_setting5_| Settings | a | b | c | d ...

Please help me design a sql query for this problem

For a particular name i want to fetch other names who have lived in three or more cities lived by this person. ...

MySQL queries - how expensive are they really?

I've heard that mysql queries are very expensive, and that you should avoid at all costs making too many of them. I'm developing a site that will be used by quite a few people, and I'm wondering: How expensive are mysql queries actually? If I have 400,000 people in my database, how expensive is it to query it for one of them? How clos...

sql: Group by x,y,z; return grouped by x,y with lowest f(z)

This is for http://cssfingerprint.com I collect timing stats about how fast the different methods I use perform on different browsers, etc., so that I can optimize the scraping speed. Separately, I have a report about what each method returns for a handful of URLs with known-correct values, so that I can tell which methods are bogus on ...

PHP delete script, return to 'viewsubjects.php?classroom_id=NO VALUE'

Hi, As the title states... I am deleting a 'subject' from a 'classroom' I view classrooms, then can click on a classroom to view the subject for that classroom. So the link where I am viewing subjects looks like: viewsubjects.php?classroom=23 When the user selects the delete button (in a row) to remove a subject from a class, I simply...

how to avoid deadlock in mysql

I have the following query (all tables are innoDB) INSERT INTO busy_machines(machine) SELECT machine FROM all_machines WHERE machine NOT IN (SELECT machine FROM busy_machines) and machine_name!='Main' LIMIT 1 Which causes a deadlock when I run it in threads, obviously bec...

change password code error.....

I've created a code to change a password. Now it seem contain an error.before i fill the form. the page display the error message: Parse error: parse error, unexpected $end in C:\Program Files\xampp\htdocs\e-Complaint(FYP)\userChangePass.php on line 222 this the code: <?php # userChangePass.php //this page allows logged in ...

Mysql show create constraint?

Hi, Is there a easy way to query a table for its constraints(foreignkeys specificaly) like show create table, but for the constraints only? thanks, pvgoddijn ...

Automatic MySQL Database backup and email through cPanel cron

Hello, Can anybody help how to setup a automatic backup of mysql database and then emailing it to me daily? Thank You. ...

Does any SQL frontend display sub-datasheets?

I'm looking for an SQL client app that can display subdatasheets like the following: Do you know of any? ...