MYSQL :: Proper MySQL Usage

MySQL 5.0.18 - Proper Column Type For Lat/lng Coordinates?
After a healthy search, I can't figure out what I'm doing wrong. I've tried quite a few variations of DECIMAL, FLOAT, DOUBLE ... but they pad values with zeros I don't need. (I suppose zeros padded after my value won't wonk the system, but I also figure that nixing all those zeros from the database can't be a bad idea either.)

Which column type (and/or with which attributes) would be best for lat/longitude type data where the float is arbitrary...for exampe, all of the following values could be valid values...and ideally, they'll come back out of the database just the same:

12.3456789
1234.567
-123.34

Looking For Help In Getting Proper Search Results From Two MySQL Tables
I am building a site where there are several travel related products in a MySQL database. Each product has "x" amount of items. For example, Harrison Hot Springs Hotel has 3 items - Cash price, Points, and Points plus Cash.

I need to do a search on "items" that are equal to or less than the number of Points (item_points) and just can't seem to get it right. Their are two tables involved "products" and "prod_items".

This is the code I am using to get search results by product category and it works just fine. I'm sorry I've tried to indent my code properly so it's easier to read but don't know how to do that here.

//get product info and show
$get_prods = "select id, prod_name, city, prod_brief, valid_m, valid_d, valid_y, expiry_m, expiry_d, expiry_y from products where category='$category' order by city, prod_name";
$get_prods_res = mysql_query($get_prods) or die(mysql_error());

while ($prods = mysql_fetch_array($get_prods_res)) {
$prod_id = $prods[id];
$prod_name = stripslashes($prods[prod_name]);
$city = stripslashes($prods[city]);
$prod_brief = stripslashes($prods[prod_brief]);
$valid_m = $prods[valid_m];
$valid_d = $prods[valid_d];
$valid_y = $prods[valid_y];
$expiry_m = $prods[expiry_m];
$expiry_d = $prods[expiry_d];
$expiry_y = $prods[expiry_y];

echo "$prod_name - $city - <a href="prod_details.php?prod_id=$prod_id">Details</a> 
$prod_brief 
Purchase options for this product are valid until $expiry_m $expiry_d, $expiry_y ";

$prod_name = addslashes($prods[prod_name]);

//get item codes
$get_codes = "select item_code, item_desc, item_points, item_cash from prod_items where prod_name = '$prod_name' order by item_code";
$get_codes_res = mysql_query($get_codes) or die(mysql_error());

if (mysql_num_rows($get_codes_res) > 0) {
while ($codes = mysql_fetch_array($get_codes_res)) {
$prod_name = stripslashes($prods[prod_name]);
$item_code = $codes['item_code'];
$item_desc = $codes['item_desc'];
$item_desc = stripslashes($codes['item_desc']);
$item_points = $codes['item_points'];
$item_points = number_format($item_points);
$item_cash = $codes['item_cash'];
$item_cash = number_format($item_cash, 2);

if ($item_points == 0) {
echo "$item_code - $item_desc - $$item_cash ";
}
elseif ($item_cash == 0.00) {
echo "$item_code - $item_desc - $item_points points ";
}
else {
echo " $item_code - $item_desc - $item_points points plus $$item_cash ";
}
}

}

}

MySQL 4.0.xx Admin And Usage
I've recently taken over my non-profit's Web site design, administration and maintenance with relatively little MySQL experience (although I have learned a great deal very quickly). My question is, does anyone know where I can get a manual or something like the current manual "Building your Own Website Using PHP and MySQL .."(ordered from sitepoint.com site). This manual is basing the MySQL on the most current version of 5. I'm looking for something similar that addresses the 4.0.xx(27 specifically) of MySQL

Can I Limit Ram Usage In MySQL?
I just had my server shut down because my hosting company said I was using 350 to 450 megs of ram. This seems nuts to me as I'm only running a shopping cart with about 1000 items with only about 50 visitors per day.

Since they installed mysql on the server, I asked them why they hadn't configured it to work with the parameters of their system.

Their response: "Unfortunately, there is no way to limit the RAM usage for mySQL. I apologize for the inconvenience this may cause however there is no way to do this."

Do they know what they are talking about???

Allowable MySQL CPU Usage
I am running this query (with subqueries) in MySQL under Windows:
SELECT sum(quantity)/(SELECT sum(quantity) from orders), partID from orders group by partID

I noticed that it runs very slowly. It appears that MySQL is only using about 2% of CPU capacity, for some reason. The query takes almost 20 minutes to run on my table (whereas the same query takes only 1 minute in MS Access!).

Is there a way to allow MySQL to use more of the CPU, so these queries can run more quickly?

Speed / Processor Usage Of Mysql
I am running MySQL 4.0.16-nt with the myODBC connector (3.51) on an IIS5 machine. If I am inserting a record it goes like the blink of an eye - 759 inserts boom done extremely fast. Then I run an ASP script to update the 759 records just inserted like this.

SQLstmt = "UPDATE tblServer3 "
SQLstmt = SQLstmt & "SET fldLand=" & strLand
SQLStmt = SQLStmt & " WHERE fldDate='" & strNextContact & "' AND fldName='" & strName & "';"
Set RS = Conn.Execute(SQLstmt)

That specifies to filter based on name & date (I cannot filter on ID) Table has a total of 29,761 records The total table size is 2.2mb

It does indeed to do the update, but it is extremely slow, 759 records updated in about 5 minutes, 40 seconds. That is about 2.2 records a second. Processor utilization shoots up to about 50% usage per processor (2 processors) Code:

How To Convert A Varchar Field Into Proper Mysql Date Field?
I have a database in which the date is stored in varchar field in a following format: d-m-Y (06-08-2007), now the problem is that I want to change that field into mySQL date field as well as convert my older dates into MySQL date format i-e Y-m-d (2007-08-06)..

There are about 300 old entries..is there a way I can do that automatically without manually re-entering the dates again?

Mysql Setup/usage/understanding Docs
Someone have a link to some howtos or docs that easily walks you through basic setup and usage of mysql? I do not need to know the ins and outs of mysql, just enough to get it up and running smoothing/securely and basic navigation info.

MYSQL - CPU Usage High On Windows 2003
I've been working on this for about a week now... When there is a lot of activity/traffic on the site mysql procees seems to "lock up" with high CPU usage and everything in windows seems to freeze. I am running mysql 4 on IIS 6 using an odbc connection via ASP.

I've tried everything, indexing, optimizing, pooling, disabled the virus software running in the background, I even tried using my.cmf, etc, nothing seems to help. Is there anyone who can help or anyone else experiencing this same problem? Could it be a hardware issue?

Proper Environment?
I'm not sure if MySQL is the environment I'm looking for or not. All I need is a simple database to track call-in records so that if a customer has to call back and they get a different rep than the one they spoke to the first time, the new rep can look up the notes from the last call. This would be much faster and much more efficient than the system we are using currently, in which we write down the call notes using pen and paper.

We only have 4 employees who would need to use the application at this time, including myself. I have the DB written in Access 2000 right now, and it's honestly such a simple DB that it would be quicker and easier to rewrite it in MySQL rather than migrating it to the server.

I'm thinking of using MySQL for this because we used it for a similar application at one of my previous employers, and because I don't have a budget or a dedicated server and MySQL is open source and can be run off of my current machine as long as I leave it running.

Proper Case
How do I change the data to proper case? (the first letter of each word in capital)

Proper Syntax
I keep getting a syntax error. Can you someone tell me what's wrong here.

CODESELECT employee_time.eid, ids_oa.oa_name, employee_time.req_num, employee_time.num_hrs, ids_worktype.worktype, employee_time.`date`, employee_time.num_of_changes, employee_time.comments
FROM employee_time
WHERE employee_time.`date`>= 'startdate' AND employee_time.`date` <= 'enddate' AND employee_time.eid = 'analyst'
JOIN ids_oa ON employee_time.oaid=ids_oa.oaid
JOIN ids_worktype ON employee_time.work_type=ids_worktype.wid

Udf Does Not Always Show Proper Result
I am strugling for a week now with a problem of an aggregate function i just coded. It seems to be working just fine most of the time but if i run the query many times sometimes the results do not match.

I am runing mysql 5.0.45. Does anybody have an idea what the problem might be. I get the results from a view constructed out of a union of two simple selects. The last result has also a order by which is unavoidable since the function expects ordered row results.

Proper Data Type
Actually i tried with all datatypes that makes sense to me but all of them are embed the string which is path by the way without the slashes.
Say i have SQL Insert statement which writes into DB the path of my documents.

C:Documents and SettingsAdministratorkulromMy Documents
When i open the table through the phpMyAdmin 2.6.4 it looks as it follows:

"C: Documents and SettingsAdministratorkulromMy Documents"

this is 1st time i see sucha thing. Weird. So, i thought that maybe some of you have solution for my problem.btw, i am using C# 2005 as frontend. The existing insert statement works fine for MSAccess, MSSQL etc. but for mySQL it doesn't work as i expect.

Joins Not Showing Proper Output
I have two tables I want to join, I only want the profile table to be counted if there is a user that matches the profile

SELECT COUNT(uid) as count
FROM users
WHERE created > 0 AND created < 1155655377 AND status > 0

this correctly outputs
164,142

When I join the profile values table I get

SELECT COUNT(u.uid) as count
FROM {users} u
INNER JOIN {profile_values} p
ON u.uid=p.uid
WHERE created > 0 AND created < 1155655377 AND status > 0

This incorrectly outputs
3,748,411

this is a test database so it has some problems but I want to know if there is a way to filter out all the problems with profile values table and only get back values that match the users table and discards anything with the profile values table that is not in the users table.

Proper Way To Handle Old Or Disabled Data?
I have a table of profiles that users create (they can create more than one). At some point, they may want to delete that profile, however, we don't want to delete the data, we'd rather disable it. (the info will be important to us later down the line).

I'm not sure which is the better option:

A. add a status column to the 'profileList' table and when they want to "delete" the alert profile, I just set the status to: 0?

B. create a second table with the same structure called "profileList_Archive" and insert the disabled row into that table first then delete it from the live table?

Just wondering if all those disabled alerts in the same table as the active alerts will cause performance issues down the line. This table will be probably(hopefully) have grow very large over time.

Proper Case For Multiple Words
I've got a table that unfortunately has many rows that have varchar fields all in capitals, for example, WASHINGTON rather than Washington.
I've used CONCAT( UCASE(LEFT(address3,1)), LCASE(SUBSTRING(address3,2)) ), but this really only works for single word fields, for example WASHINGTON STATE. Can someone here help me with a function or procedure? Or has someone done it before.
Usually we would do this in the application code however time is of the essence here and our application coding is outsourced (company would charge us a fortune for even a small change).

UPDATE Multiple Values - Proper Syntax?
I use powerbuilder with mysql database.I want to get server's datetime.

/tmp Usage
are there any best practices for /tmp on a std *nix install for MySQL, and if so, what are they ? Also i can't seem to find any more information on what specifically you'd require a LARGE /tmp for in MySQL.

C# Usage
Does anyone know if C# will work with mysql??? I know it does C++, but I don't know if the connectors or whatever are out there for C#

MAX() Query Usage
I have a database of marks and I need to find out the maximum mark taken by each student in any subject. For example If am a student and I have got 60 in Language, 70 in Maths, 80 in Science and 90 in Social Studies, I would need the result "90" and the relevant Social Science subject to be displayed so that I know am good at Social Science of all the subjects.

Likewise, my friend got 65 in commerce, 70 in accountancy, 80 in economics and 90 in Applied Maths. As you may see here, the subjects are all different in both these cases. I only need to know this following result

That I am good at Social Studies and
my friend is good in Applied Maths.

The table name is marks. The fields are subject_id, mark_obtained, student_id.

When I try this query.

Select subject_id, max(mark_obtained) from marks group by student_id

In this case, I get the correct maximum mark, but the subject id displayed is incorrect. Can anyone tell me what am doing wrong here?

Getting CPU Usage Of A Query
There are some various queries running on my site that appear to use a whole lot of CPU resources under certain conditions which I haven't identified.

Is there any way I can see which queries are using up how much of the CPU instead of just being able to see the general process id for MySQL? I use cPanel and WHM to manage the server.

Index Usage
I have two tables, one is Student, which has studentid, personid, grade, fees as its columns. The other one is Person, which has personid, firstname, lastname, address as its columns. When given a studentid, I need to get the student' info, such as
lastname from the db tables.

I can do it with two queries as the following:

1. mysql> select personid FROM Student where studentid=1;
2. mysql> select lastname FROM Person where personid="the id I got above";

Or I can do it with one query:

3. mysql> select p.lastname from Student s, Person p where s.studentid=1 AND s.personid=p.personid

Both works. However, I can't tell which one is actually faster, since MySQL shows me "1 row in set (0.00 sec)" for all these three queries. Both studentid and personid are primary keys, so they are automatically indexed.

Will both indexes be used in query number 3? I saw people said that

MySQL could use in a query only one index...Does it mean only one index will be used in query number 3? I am wondering which one will give better performance.

Max(count(*)) Usage?
I have a table with a structure along the lines of

customerId
itemId
copyId

which form a primary key.

I want to know the max occurence of a particular item, based on copyId.

Ie, if 5 customers want itemId 6, 3 want copyId 1, 2 want copyId 2, should return 3 for itemId 6..

I thought something like

select itemId, max(count(*))
from items
group by itemId

might work, but alack, not the case.

Suggestions in how to do this with one query?

Counting Usage Per Day
I want to record how many times an application is used in a day. Is it possible to create a table with a date field that automatically creates a new record each day with the present date as the primary key.

Memory Usage
I've been analysing the memory usage of our server and each SQL thread seems to be taking up 10mb - since our site is basically a search site that means we're using 10mb per user which means with our 2gb RAM we can take around 120-200 simultaneous visitors.

Other than buying more RAM, what can I do to increase the number of simultaneous connections (ie - how can I reduce memory usage?) By my Calculations we need to be able to accept around 500 simultaneous searchers to meet our target.

We will also be increasing the amount of data we have - currently it is around 1.5 million records but that will be gradually increasing to around 10 million - which I'm sure will also increase the memory load on the server. Right now we have 1.4Gb Data and 380Kb overhead.

CURRENT_DATE Usage
I am trying to access some data from a database based on the date.

here is the SQL:

SELECT internallocation.LocationName, breed.BreedName, animal.DateBroughtIn from breed, animal, internallocation where (breed.ID = animal.BreedID AND internallocation.ID = animal.ShelterLocation AND animal.DateBroughtIn = 'CURRENT_DATE()')

This command returns no results... however, if I put in the date like so:

SELECT internallocation.LocationName, breed.BreedName, animal.DateBroughtIn from breed, animal, internallocation where (breed.ID = animal.BreedID AND internallocation.ID = animal.ShelterLocation AND animal.DateBroughtIn = '2005-06-24')

I get the results I am looking for. How can I use CURRENT_DATE to create a report based on the date, so the SQL does not have to be edited every time to change the day?

Wildcard Usage
Here is an example of the code:

$query = "SELECT * FROM table WHERE field = '*' ";

I want to return all the fields from the table where the field is any.

The program is a little more complicated than this. Basically using a dropdown menu, the user can search all, or a particular field. If they select "search all", I need the ability to insert that into the query statement.

Memory Usage
We have Mysql 5.0 running on RH linux. We have noticed that the swap memory increases but never gets released unless we reboot the server every 2-3 weeks. How would I know whats using this swap memory?
Second question which I think maybe related to the first is that mysql is using a lot of memory when I do a top. Is there a way to limit the memory usage of mysql? I have a large table in mysql about 7 GB and I have 8 GB physical memory and swam is set to use 2GB.

LEFT JOIN Usage HELP!
Schema:

Table1
-t1field1 --> primary key
-t1field2
-t1field3

Table2
-t2id
-t1field1 --> foreign key of t1field1
-t2field2
-t2field3
-t2field4

Database Values:
Table1
row1: 1,aaa,123
row2: 2,bbb,123
row3: 3,ccc,123
row4: 4,ddd,123
row5: 5,eee,123

Table2
row1: 1,1,aaa,123
row2: 2,1,jjj,123
row3: 3,1,aaa,123
row4: 4,2,hhh,123
row5: 5,3,hhh,123
row6: 6,2,aaa,123
row7: 7,1,jjj,123

Query:
SELECT
t1.t1field1,
t1.t1field2,
t1.t1field3,
t2.t2field2,
t2.t2field3,
t2.t2field4
FROM
Table1 AS t1
LEFT JOIN
Table2 AS t2
USING(t1field1)
WHERE
t1.t1field2 = 'aaa'

Question:
Where do I insert a "WHERE clause" if i wanted to get t2.field2 with a value of 'jjj' only? or my query is totally wrong.

High CPU Usage (99.9%) On RHEL4
i need your help on this issue. I am running a web server in my orginazation internally with mysql-4.1.12 and RHEL4. Now, its been only one day and using 'top' command its showing mysqld process using cpu 99.9% constantly. This is used by say around 4000 users.

My my.cnf file :
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

[mysql.server]
user=mysql
basedir=/var/lib

[mysqld_safe]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

output of mysqladmin version
..........
...
Threads: 53 Questions: 324297 Slow queries: 588 Opens: 39976 Flush tables: 1 Open tables: 64 Queries per second avg: 67.788

output of mysqladmin extended-status
Variable_name | Value |
+--------------------------------+------------+
| Aborted_clients | 742 |
| Aborted_connects | 35 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Bytes_received | 29401860 |
| Bytes_sent | 1049908921 |
| Com_admin_commands | 2352 |
| Com_alter_db | 0 |
| Com_alter_table | 0 |
| Com_analyze | 1 |
| Com_backup_table | 0 |
| Com_begin | 0 |
| Com_change_db | 40895 |
| Com_change_master ...................................................................

Calculating Table Usage
how posiible is it to calculate a table usage in byte.

Analyze Index Usage
I am running a SELECT query that is taking approx. 200+ seconds to complete. I believe I have the tables indexed properly, but apprarently not. How can I determine what indexes a query is using and evaluate the execution plan (as you would in MSSQL)?

CPU Usage Issues On A Windows Box?
As the site receives over 50 simultaneous hits, mysql uses up just about all cpu usage... I have fine tuned everything - can any one offer any suggestions or share similar experiences??

Orders Table - 100% CPU Usage
I'm starting to dive into something that looks like a PHP/MySQL issue that is bogging me down (PHP5, MySQL 4.1, Apache 2 on a Windows XP ws).

(At the end of this message, the PHP code)

We operate a virtual store and there's this administrative tool, loaded by the code included, which lists orders by category (new, shipped, cancelled etc.); on the top of the page, it first shows each category's totals (3 new, 18 shipped etc.). Obviously, these data comes from an "orders" table which, as of today, has 8.103 records.

I did increase already cache and buffer sizes on PHP and that helped tremendously to load the tool *if data doesn't change* in between. When it does, the following happens:

1. CPU usage goes all the way up to 100%, and
2. it takes approx. 45-60 seconds like that until the page ends loading.

I'm no PHP programmer, but it seems to me this has to be related to the code below.

Code:

Lowering Memory Usage?
I was wondering if there's any way I can lower MySQL's = memory

useage? It often uses more than 50000kb which I consider to much.. I'm guessing I should play with my.cnf or whatever it's called (located at = C:/ and windows calls it cardnumber or something)...

Mysqld Running 100 Pct Cpu Usage
I am testing mysql 4.1 on a Windows Server 2003 with a website running on Internet Information Services. I installed mysqld as a service.

As times goes by, mysqld begins to reach 100 pct cpu usage and doesn't goes below that, Windows usage is slow, folders opens slow, navigating locally turns to be slow, and sometimes it makes the server to freeze or restart.

When this begins to happen, I executed the command "Show processlist" and I got the following result. If somebody can point me where is my mistake or where is the problem or any solutions for this, I'm still in a learning process for mysql. Code:

Key_index_size Setting And Usage
I am using MySQL 4.1.12, compiled from source, on a Linux 2.6.11.10 kernel form the kernel archive. My Hardware is a Dual Xeon 2.8Ghz with 8GB of RAM and U320 SCSI disks. The database I am serving is about 6GB total, with the bulk of the data in 2 big tables, about 1.5 GB each.

The index files for these two tables are 1.4 GB and 415MB. In my /etc/my.cnf file I have the key_index_size set to 3GB, but the most that will get used is 1.49GB, either after doing an "Optimize tables" or an "INSERT INDEX INTO CACHE" statement.

My question is: How does MySQL decide how much of the systems memory to use for the key_index_size and any other of the processes allocatable address space. Also, under linux is the allocatable address space to an individual process 3GB or 4GB?

Usage Of OPTIMIZE Command
I had a table of more than 800'000 rows where I deleted approx 200'000 rows. The documentation says that I shouldn't normally have to use the OPTIMIZE TABLE command, but performance on this table has not improved. Is it a good idea to use it?

Usage Of DELETE In A Query!
I know just enough about MySQL to insert, update and if necessary alter tables. But I helped someone that was wanting to delete a rwo of data selected with a form which presented all the row and had a link to take them to another page where it was confirmed by clicking another sumbit button that would remove the row selected from the prior page, then they sent a Private Message stating that the code worked, but then mentioned something about having a foreign key and not being able to delete that field. It is my limited understanding but if I had a table and did

DELETE FROM tablename WHERE orderid='$orderid'

then this would remove this row whatever the row with an orderis that matched. I built my own table which merely consisted of an autoincrementing PRIMARY KEY of orderid and when I tested the code the row was in fact removed, so what if there were a foreign key? I don't think it would matter, but after the PM I wonder.

Lowering Memory Usage
there's any way I can lower MySQL's =
memory
useage? It often uses more than 50000kb which I consider to much.. I'm
guessing I should play with my.cnf or whatever it's called (located at =
C:/
and windows calls it cardnumber or something)

Measuring Database Usage
I'm trying to write a backup script, but want to be 'resource smart' about it. I'd like to backup my database every hour or 2, but want to look at the current draw on the DB prior to running the backup. If the draw is within pre specified limits, do the backup, otherwise, sleep for a min then try again.
This may be more of a job for a shell script, but I figured I'd give the mysql forum a try.

Showing Disk Usage
How can I see how much disk space is being occupied by an InnoDB table?

Looking into /var/lib/mysql doesn't seem to work anymore for InnoDB tables.

Please tell also if there is a way to see how much space is occupied by
a particular row or column of a table.

4.0.14 Runs CPU Usage Up And Eventually Stop
I am running 4.0.14 on a FreeBSD 4.8-STABLE machine (upgraded to CVS
from last week) and I am having a problem. We run a fairly large website
using PHP so there is always many connections to the database. On 4.0.12
the cpu usage never shot to over 20% and ran extremely fast. After
upgrading to 4.0.14, the cpu goes anywhere between 20-60% and in many
situations will not accept any database connections. After browsing the
website for a few minutes, I will type mysql on the command line and it
will give an error of too many connections. Does anyone know what may be
causing this high load from the upgrade? Again the previous versions did
not do this and ran very well. I could use 4.0.12 but I wanted to report
this in case it continues in future versions.

Single Computer (stand-alone) Usage?
I'm hoping to install MySQL on my home desktop computer (where I'm running Ubuntu Linux) and come close to simulating conditions at work (where we use MS Windows XP/Server/SQL Server). I'm also interested in doing this for an online "SQL Intro" course I'm going to be taking in October...

Is it possible to install MySQL and work from my desktop PC as both the server and the client? If so, can somebody point me towards some documentation?

Configuration And Usage Of The Relation Feature
im just creating a new database for a browser roleplaying game. Maybe you can imagine how complex this can be sometimes. And while i was working on it i remembered a feature of the MS access database. At access you could create relations for various tables, so if u change a field in one table, it is changed for all fields related/linked to it.

Is there a similar feature in mysql, and if yes, is it the "linked_tables" feature?

4.0.14 Runs CPU Usage Up And Eventually Stop
I am running 4.0.14 on a FreeBSD 4.8-STABLE machine (upgraded to CVS
from last week) and I am having a problem. We run a fairly large website
using PHP so there is always many connections to the database. On 4.0.12
the cpu usage never shot to over 20% and ran extremely fast. After
upgrading to 4.0.14, the cpu goes anywhere between 20-60% and in many
situations will not accept any database connections.

After browsing the
website for a few minutes, I will type mysql on the command line and it
will give an error of too many connections. Does anyone know what may be
causing this high load from the upgrade? Again the previous versions did
not do this and ran very well. I could use 4.0.12 but I wanted to report
this in case it continues in future versions.