mysql

MySQL: how to index an "OR" clause

I'm executing the following query SELECT COUNT(*) FROM table WHERE field1='value' AND (field2 >= 1000 OR field3 >= 2000) There is one index over field1 and another composited over field2&field3. I see MySQL always selects the field1 index and then makes a join using the other two fields which is quite bad because it needs to join 146...

MySQL::Eliminating redundant elements from a table?

I have a table like this: +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | v1 | int(11) | YES | MUL | NULL | | | v2 | int(11) | YES | MUL | NULL | | +-------+---------+------+-----+---------+-------+ Th...

mysql - funny square characters added to the value when inserting it into table

Hi, I have a php script that inserts values into mySQL table INSERT INTO stories (title) VALUES('$_REQUEST[title]); I checked the values of my request variables before going into the table and it's fine. But when I add title=john to the table for example, I get something like this: title = "[][][][]john" and when I extract the valu...

is it possible to create a search engine to index new jobs from many company websites?

I dont think it's possible without some xml/api given by the employer websites? basically can i extract and identify information from a html page? ...

what does rs.Fields(0) mean? (ADODB) VBA

dim rs As ADODB.Recordset ... ... ... capture_id = rs.Fields(0) what does .Fields(0) mean? ...

What might be causing this Rails method error?

My error: Notice the undefined method '-@' . This is for a sort by. All sorts on one page break, but all the sorts on other pages use the same helper and do not break. Does it allude to something obvious? Processing OrganizationsController#search (for ::1 at 2010-05-13 15:42:01) [GET] Parameters: {"action"=>"search", "controller"=>"or...

Consecutive absences in MySQL

Hi, I have 2 tables in my db: students and absences. In students: id_student, s_name; and in absences: id_student, date, day(the day of the week as number-it's not so important); I would like to get the students that were absent for more than 2 days consecutive and the dates. At the moment I have the next query: /*To control when the...

Enforcing a query in MySql to use a specific index

Hi, I have large table. consisting of only 3 columns (id(INT),bookmarkID(INT),tagID(INT)).I have two BTREE indexes one for each bookmarkID and tagID columns.This table has about 21 Million records. I am trying to run this query: SELECT bookmarkID,COUNT(bookmarkID) AS count FROM bookmark_tag_map GROUP BY tagID,bookmarkID HAVING tagID IN ...

setting codeigniter mysql datetime column to time() always sets it to 0

Hi guys. I'm using Codeigniter for a small project, and my model works correctly except for the dates. I have a column defined: created_at datetime not null and my model code includes in its array passed into db->insert: 'created_at' => time() This produces a datetime value of 0000-00-00 00:00:00. When I change it to: 'created_at...

Effects of order of columns, while defining an index on them, on the performance of the queries

Hi, Does order of the columns in an Index definition for a table in a database has any effect on the performance? for e.g. are these two queries different ? CREATE INDEX xxx ON tablex(col1,col2) CREATE INDEX xxx ON tablex(col2,col1) what about the in case that I use a BTREE index? I am using Mysql. thanks ...

Stop invalid data in a attribute with foreign key constraint using triggers?

How to specify a trigger which checks if the data inserted into a tables foreign key attribute, actually exists in the references table. If it exist no action should be performed , else the trigger should delete the inserted tuple. Eg: Consider have 2 tables R(A int Primary Key) and S(B int Primary Key , A int For...

A SELECT statement for Mysql

I have this table: id,bookmarkID,tagID I want to fetch the top N bookmarkIDs for a given list of tags. Does anyone know a very fast solution for this? the table is quite large(12 million records) I am using MySql ...

Migrate from MySQL to PostgreSQL on Linux (Kubuntu)

A long time ago in a galaxy far, far away... Trying to migrate a database from MySQL to PostgreSQL. All the documentation I have read covers, in great detail, how to migrate the structure. I have found very little documentation on migrating the data. The schema has 13 tables (which have been migrated successfully) and 9 GB of data. MyS...

Copying contents of a MySQL table to a table in another (local) database

I have two MySQL databases for my site - one is for a production environment and the other, much smaller, is for a testing/development environment. Both have identical schemas (except when I am testing something I intend to change, of course). A small number of the tables are for internationalisation purposes: TransLanguage - non-Englis...

Django Encoding Issues with MySQL

Okay, so I have a MySQL database set up. Most of the tables are latin1 and Django handles them fine. But, some of them are UTF-8 and Django does not handle them. Here's a sample table (these tables are all from django-geonames): DROP TABLE IF EXISTS `geoname`; SET @saved_cs_client = @@character_set_client; SET character_set_client ...

Retrieving multiple rows from a loop-created form... Stuck.

Let me start by saying that I'm new to PHP, but I'm here to learn and would really appreciate your help. I use the following code to pull in data and create a form. This creates up to 40 lines for a user to fill out. Each line consists of the same information: Description, Amount, and Frequency. The remainder of the information needed ...

Which of the two ways should I use to insert tags into mysql?

For each ad, I allow users to choose up to 5 tags. Right now, in my database, I have it like... Posting_id TagID 5 1 5 2 5 3 6 5 6 1 But i was thinking if I should make it like... Posting_id TagID 5 1 2 3 6 5 1 ...

Mysql : Count Posts and Group by date

Hello , I am not very good at sql , generally I use php to do my complicated tasks , But in this task , there are lots of data , so using php for counting posts is very slow. So I want a sql which counts post by date , but my date column in table is php's time stamp (int).I will crate post number x date chart ...

MySQL Query to get count of unique values?

Hits Table: hid | lid | IP 1 | 1 | 123.123.123.123 2 | 1 | 123.123.123.123 3 | 2 | 123.123.123.123 4 | 2 | 123.123.123.123 5 | 2 | 123.123.123.124 6 | 2 | 123.123.123.124 7 | 3 | 123.123.123.124 8 | 3 | 123.123.123.124 9 | 3 | 123.123.123.124 As you can see, there following are the unique hits for t...

Mysql change column details

I am trying to redefine the number of varchars a column can have (in a MySQL db). I am doing alter table obj_details IMG_SRC IMG_SRC varchar(180); I want to change the number of characters that can be used in the column IMG_SRC to 180 (it is currently 100). But I get an error saying that I should check the syntax near IMG_SRC IMG_SR...