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What Is The Maximum Possible Number Of Fields In A Table?


What is the theoretical and practical limits of number of fields in a table?
Say I have 1000 or 10000 integer fields in a table, does the query processing speed decrease?




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Maximum Number Of Fields
I'm trying to create a table with 21 fields and I'm failing miserably.
Is there a maximum limit? Or am I just blind to a typo?
here's the command (in PHP):
$resultID = mysql_query("CREATE TABLE wordforms (WordForm CHAR(100),
Language CHAR(100), Category CHAR(100), Lexeme CHAR(100), Case
CHAR(100), Number CHAR(100), Gender CHAR(100), Person CHAR(100), Tense
CHAR(100), VerbForm CHAR(100), Degree CHAR(100), Adjective CHAR(100),
VerbStrength CHAR(100), VerbType CHAR (100), Modal CHAR(100),
Conjunction CHAR(100), Preposition CHAR(100), VerbMotionStatic
CHAR(100), VerbArguments CHAR(100), VerbTransitivity CHAR(100),
VerbObjectCase CHAR(100))", $linkID);

Maximum Number Of Fields Allowed In MySQL Row?
I'm trying to create a table with 21 fields and I'm failing miserably.
Is there a maximum limit? Or am I just blind to a typo?

Here's the command (in PHP): Code:

Maximum Fields In A Table
I have a website which runs pretty slow... I have turned on the SLOW-QUERY-LOG, and there's one table that is in the log over and over again...
It's the table which stores 99% of the user information.
This table has 61 fields, and alot of these are varChar and their set at 100 or so....
Anyways, I was curious what is the maximum amount of fields you should have in table, and in my case should I split the data between several tables and just use a complex Join statement?

Maximum Allowed Tables/db, Fields/tables, Records/table
1)tables that can be created in a MySql database.
2)fields that can be created in a MySql table.
3)records allowed in a MySql table and in a MySql database.
4) allowed joins in a MySql table/database.

Limit To The Number Of Columns/fields That Can Be Held In A Table?
is there a limit to the number of columns/fields that can be held in a table?

Maximum Number Of Tables?
What is the maximum number of tables you can put into a mysql database?

Get Maximum Number From A Field
I would like to know if there is a way to retrieve the largest number in a group of records using a MySQL built-in function.

Print The Maximum Number
i have a table with two fields: name and age.

how would i get the name and the age of the oldest person in the table...same with the youngest...what about the average age?

Maximum Number Of Rows
I am looking for information on the total number rows that can be used in an InnoDB,if there is even such a limit.I am not a DBA, so the information on mysql is a bit cryptic.

Maximum Number Of Columns
Is there a Maximum number of columns allowed in MySQL 3.*.

Maximum Number Of Databases / Schema
Are there any known limitations about the number of used databases/schema within a single database connection?
We try to create an application that should use up to several hundred databases/schema within the same database connection and I found no documentation about any limits for this handling.
We want to use MySQL 5.0 or 5.1.

Increasing Maximum Number Of Columns
I have a requirement for tables with thousands of columns. I know this is not typical, but these tables are both application-generated and appplication-read. We need a minimum of ~3000 columns. I thought MySQL supported this ... but we can't get past 1000 (4.1.18) Any ideas?

Find The Maximum Of The Sum Of Some Fields.
I want to select the biggest result which I get by adding the fields named "vote" with the same user_id. I thought of the following (but it didn't work out, unfortunately):

SELECT max(sum(rating)) FROM votes WHERE user_id = $user_id

Could anyone help me with this?

Using A Query To Determine The Maximum Value A Number Col Can Hold?
I'm trying to find out how can you determine the largest value you can enter into a column of type smallint,mediumint,int, etc using a query. I know what the values are by looking at the documentation, but I would like to get this number using a query at runtime. So when I insert values into different tables/columns I can use an appropiate restriction befor trying to insert.

Maximum Number Of Rows Mysql Can Retrive
Basically I want to know the max rows mysql returns for a select. Heard that MSsql would retrive about 100 rows.

Selecting A MINIMUM And MAXIMUM Number Of Rows.
I have a problem where I want to get no more than 10 (LIMIT) of the newest records from a table that are within a month, but I want to get at MINIMUM 3 records, all using SQL.

I can do :

-------------------
SELECT *
FROM updates
WHERE date_of_update
BETWEEN DATE_SUB( CURDATE( ) , INTERVAL 1
MONTH ) AND CURDATE( )
ORDER BY date_of_update DESC
LIMIT 0 , 10
-------------------

To limit it to the 10 updates no older than a month, but if there are no updates within a month I get nothing.

So I would like to do something like :

-------------------
SELECT *
FROM updates
WHERE ROWNUM() < 3 OR ((date_of_update
BETWEEN DATE_SUB( CURDATE( ) , INTERVAL 1
MONTH ) AND CURDATE( )) AND update_id IN (
SELECT *
FROM updates
ORDER BY date_of_update DESC
LIMIT 0, 10
))
-------------------

This code will take the 10 most recent updates and then starts pulling them out as long as the number of rows is less less than 3 or the update is within the date range and one of the 10 recent updates. The problem is that mySQL appears not to have any kind of rownum function.

Limit is a nice substitute except it only works for setting an upper bound, not a lower bound number of records.

Maximum Number Of Databases In A Single Installation
I'm checking out MySQL 5.0.45 and am wondering what is the greatest number of databases I can create on a given installation. I have only been able to find information on max tables and max columns per db.

What performance issues may be involved when running at or close to the max number of DBs.

What changes to default settings would need to happen in order to run a server with max db's given a high amount of available RAM and disk storage?

Maximum Number Of Columns And Actual Data In A Row
SUMMARY:
I need to know what the actual maximum date limit possible on a row of
a MYSQL database.

MORE DETAILS:

For example, does a MYSQL database only allow 4032 bytes of data to be
stored in one row or is there no limit? Does it only allow a maximum
of 50 colmums?

I tried googling on this, but all the results seem to be about
recommended maximums or design style. As an ex-Access developer I
remeber hitting a limit with the Access DB which I think was that one
row could contain 2048 bytes max(things like blobs do not contribute
to this limit). I'm hoping there are no limitations with MYSQL.

My reason for asking is that I have been asked to add new fields to
someone elses DB. There are already a lot of columns and the short and
dirty fix for me which would mean minimul PHP script changes is by
adding new fields to the current table. But there are already quite a
few so thought I would check.

Maximum Number Of Connections In MYSQL (community Server)
how many maximum connections can reside in connection pool of MySQL server- community? Also what are the major differences between the Enterprise and community server versions?

Max Number Of Fields
I have product table , it has 40 fields , is it a bad thing to have that many fields?

secondly On one page , I have 4 select statements, is it bad pratice to have so many select statemnts, it may slow down the page?

Calculate The Number Of Fields With Value X
I need to retrieve from a database a number of fields where field_x = y. How can I do it?

Maximum Rows In Table
I heard there's a max of about 65k rows not counting longtext and blobs in a mysql table

How does longtext and blobs affect the max row count? And, what happens if you go over the max rows -- does the table auto-trim or does everything blow up? (Sorry... too scared to try myself )

Maximum Records In A Table
Is there a limit or design limit on the numbers of records a table can hold using mysql?

Query Fields That Start With A Number
I am building an index for our Client List page, which lists over 400 clients of ours.  I want to change the SELECT query that returns the resultset that is shown to select ONLY records that start with a certain letter.  This is being done with the addition of the following code to my MySQL query:

$query_Clients .= "WHERE clientName LIKE '".$_GET['letter']."%' ";

Database Of Dynamic Number Of Fields
for instance a baseball game may have 9 or more innings, suppose you wanted to store like a boxscore for each date for both teams that played, any ideas for the best way to accomplish this? Im basically trying to pull the data of a box score from a mysql database, but not sure on what would be the best way to store. I hope that is clear enough.

To sum it up: I basically want to maintain a database of every boxscore that can be accessed by clicking a link to the date and displaying it neatly in a table or such......

How To Find Number Of Non-null Fields In Each Record?
I have a number of fields say S1 to S5. I want to check how many of these have been filled up in each record. Then I want find how many records have only one of S1-S5 filled up, how many have two etc.

See this table below,

Name S1 S2 S3 S4 S5
A 231 123 NULL NULL NULL
B NULL NULL 101 NULL NULL
C 123 101 431 109 213
D NULL NULL NULL NULL 101
E 101 NULL NULL NULL 109

So, after my intended query is run, I get,

Fill Count Frequency
1 2
2 2
3 0
4 0
5 1

Fields In One Table Overwrite Fields In Another Via JOIN
I'm writing a simple web game which uses mysql to store data. The prototype works ok so far, but now I'm refactoring it to support multiple players. This means coming up with a way to store the player's current world state.

I'm thinking of doing this by having a table that defines the initial world state, and then a table containing the 'state' of anything different.

Example:
The 'objects' table looks like this:
object_id, name, room
1, Hammer, 1
2, Mirror, 1
3, Spade, 2

So, at the start, room 1 contains a hammer and a mirror, and room 2 contains a spade.
Now, if player 12 picks up the hammer then drops it in room 2, I store this override in the 'state' table

player_id, object_id, room
12, 1, 2

So. I'm trying to see if there's any kind of join syntax that would return all the objects in a room for a given player's 'session'. Obviously it could be done with temporary tables, or just comparison outside of SQL, but I keep thinking this might be possible *somehow*

One Table With Many Fields Or Many Tables With Few Fields?
I need to build a database, but I'm torn between these 2 choices:

Is it better to have one table which has many fields
or
many tables which each has few fields?

Is it true that the latter is worse because it will require many join operations?
What is the limitation of the first option (one table with many fields)?

Fixed Table, Variable Number Of References To Another Table?
I have two tables A and B. I want to have a column in table A that can reference to zero or more rows in table B. Is there a way to do this without making my table dynamic? I want to keep it fixed. Is there a solution or workaround?

Table Number Limit?
Is there a limit to the number of tables allowed in MySQL? Is there any
non-obvious performance hit associated with having too many tables?

Assume the data size will be the same. In other words, having a table that
is 1.5Gig versus having 1000 tables that are each 1.5MB in size.

Table: Max Number Of Rows
In a table what is the limit to the number of rows that make it up?
Is the only limitation HardDrive space?

Number Of Rows In Table
Is there a query which returns the number of rows in a table without using a "SELECT..." followed by recordset.RowCount?

Add Phone Number To Table
I have set up my phone field as an "int"

The problem is, if i type : 1300 45 15 12

I will only populate the phone filed with : 1300
The spaces are an issue, i am not sure on how to fix this.

Number Of Table Rows
I have tried to answer this question by using Google but my search didn't bear any fruits, so to speak.

I am in the middle of designing my db and i have just thought that in some of my tables i think i will have 1000s of entries [rows] and if my web application with a db backend is successful it can turn into millions of rows [wishful] - so i wanted to know is there a limit in the number of rows for a table? I think not, but how will performance be effected?I am using a MySQL database, I am using a linux server not sure if this matters but microsft and i dont get along.

Number Of Columns In Table ? Is There Any Limit?
My question may sound stupid but i really want to know if there is some kind of recommended limit for number of columns in a table of mysql table.
For example, is it okay if i make 100 colums in one mysql table? or i should make more tables to decrease number of columns?

Limiting Number Of Rows In A Table
I'm trying to implement a basic log in a table. Instead of writing to a text
file on the server, I want to insert entries into a 'log' table. However, I
want to limit this table to only have the last 500 rows or so. How do I do
this?

Here's my pseudocode, but it seems as if there would be a better way:

logEntry($message){
insert message into table
get number of rows in table
if (numrows > 500){
delete from table where ((numrows - id) > 500)
}
}

Is that right?

What Is The Max Number Of Rows A MYSQL Table Can Contain
What is the max number of rows a MYSQL table can contain.

Count Number Of Columns In A Table
Using MYsql 4.0. I have a table with A LOT of columns. Is there a syntax/query that will give me the number of columns in my table??

Trigger To Increase Number On Certain Row On Other Table
I'm trying to create trigger as explained below:

I make the followin insert to "Table_a"
INSERT INTO Table_a (id,desc,loc) VALUES (1234,'some stuff','some where');

at that moment Table_b contains following data

id | quant
-------------
1234 | 4
2324 | 6
2543 | 8

everytime time insert is made on Table_a trigger should find a row with matching id from Table_b and increase quant field by one.
So basically after trigger has ran Table_b should be like:
id | quant
-------------
1234 | 5
2324 | 6
2543 | 8

Is that possible?

Getting All Fields From A Table And ONLY ONE From Another One
maybe it's time to get some rest, today...

SELECT * , User_Avatar
FROM restaurantsrate, users
WHERE Card_ID =222443
AND Ratings_Deleted =0
AND Ratings_UserID = User_ID
LIMIT 0 , 30

I'm trying to get all fields from table restaurantsrate and only User_Avatar from table users, but I'm getting ALL fields from both tables? anyone can help?

How Many Fields Can A Table Have?
I'm presuming you can have as many fields as you'd like, but I'm just curious as to what the maximum recommended is. Is it ever better to split the fields over 2 tables instead of one? even though most the time if you're grabbing data from table1, you'll also be getting data from table2. The question popped into my head as I was making a "Orders" table for an online store. It has 39 fields so far and I'll probably need to add a few more (depending on what other information the client needs to know about their customer orders).

Table Fields
Is it ok to have a big table with 27 fields or should I try and split it down into smaller tables. It kind of makes sense all being in one table to me, but if that is bad design then I would break it down.

Sum 2 Fields From 2 Table
I have facing a problem to sum 2 fields from 2 table.

SELECT Table1.Stud_Number, Sum(table1.School_fee), Sum(table2.libary)
FROM Table1, Table2 WHERE Table1.Stud_Number = Table2.Stud_Number
GROUP BY Stud_Number

Db Table Fields
Is there an industry standard or best practice some of you more experienced developers could pass along concerning the number of characters I should define in my tables for a person's first name, last name, username, phone, email... and any other fields you think worth mentioning?

My Password is encrypted with sha1(), so that field is 40 characters long.

I'm looking to keep the tables as efficient as possible, so I'd like to follow some 'norms' if there are any.

Fields In Table
How do I fix this error? My tables have data.

More Than 50 Fields In A Table
I had made a table which contains more than 50 fields..
I am afraid this will hamper later ..
What i want to know ?
1>how many fields should be in a table for optimization ?
2>what should taken into consideration for future hazards in case there are more than
50 fields in table ?

Getting Number Of Rows From Left Join Table
PHP

SELECT bulletin.id AS bid,           bulletin.bulletinname AS bname,           bulletin.bulletindesc AS bdesc,           bulletin_post.id AS postid,           DATE_FORMAT(bulletin_post.postingtime,'%M %d, %Y %l:%i%p') AS postdate,           bulletin_post.bulletintitle AS ptitle,           member.screenname AS mname,           member.id AS posterid           FROM bulletin           LEFT OUTER JOIN bulletin_post           ON bulletin.id = bulletin_post.bulletinid           AND bulletin_post.postingtime = (SELECT MAX(postingtime) FROM bulletin_post WHERE bulletinid = bid)           LEFT JOIN member           ON member.id = bulletin_post.memberid                    WHERE bulletin.active = 1           ORDER BY bulletin.bulletinname ASC

My question is how would I get the count of rows if any from the bulletin_post table?

How To Add 3600 To A Number Field In Every Record In A Table?
I would like to know how to increase values in a table. for example I have table with few text fields and a number field. I want to add 3000 to the number field in every line in the table.

SUM Of Two Foreign Table Fields
I've a project that has many timesheets (time) and many expenses (money)

I'm trying to work out the cost of the project base on a set amount per hour for timesheets plus expenses.

A project may not always have expenses.

A project has zero or many timesheets
A project has zero or many expenses

I need an SQL statement to return total time for a project and total expenses so i can do my calculations then in php. I'd prefer do this in one SQL statement.

What i have so far:

SELECT project.name, SUM(timesheet.time) AS time, SUM(expenses.amount) AS expense
FROM project, timesheet, expenses
WHERE project.id = timesheet.project_id
AND project.id = expenses.project_id
GROUP by project.id

==TABLES==

PROJECT
id PK
name

TIMESHEET
id PK
project_id FK
time

EXPENSES
id PK
project_id FK
amount
This will work fine for all projects that have both at least one expense and one timesheet. But if they are missing one then it returns no row for that project and therefore i can't display the cost.

There are other pieces of data but these are the only important ones. I can do it in two different SQL statements but i really think there has to be a way to do it in one.


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