Under mysql variables sql mode STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION has been removed. My server gets auto updated and the Value
STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION returns.
Under Update Preferences Daily Updates has been set to Never Update, Operating System Package update is set to Never Update.
The server (phpmyadmin) gets updated regularly, and shows:
ERROR No 1364 "Field 'coloumn_name' doesn't have a default value"
My server is from Godaddy
Kindly help..
This is a bit odd because the person (or software) that handles your updates should have updated the table structure for you, but it appears to be a pretty easy fix. phpMyAdmin has an optional database that enables advanced features. It sounds like that database structure wasn't updated when the rest of the phpMyAdmin code was updated.
Your situation is a bit odd in that the column_name column hasn't been changed since at least 2009, which basically means whatever version you were running must have been quite outdated.
In the sql folder (or a different folder if your current phpMyAdmin is still quite old, such as scripts or maybe examples), there are various .sql files which can help with updating your installation. You may wish to run create_tables.sql, but that won't always upgrade existing tables so, again depending on the versions involved, you may be better of dropping the table outright and running that script to create them. I don't see anything in the two current upgrade scripts that would affect column_info, so either that change is so old it's been removed or something else odd happened. You may also want to try doing it manually; if you go to edit that column's structure you can add a default of ''.
Related
I updated the SCHEMA of a live table in MySQL for use in my multi-user database. Each user has their own db and links to the production tables through ODBC.
I have been receiving a write error while trying to test my schema updates. I cannot find the core reason. I hypothesized that because the other users are in the production table but have not been relinked to update the table SCHEMA; That it is causing a conflicting write error on my relinked table.
I added a TINYINT with No NULLS and default value of 0
I double checked all datatypes for incompatibility & have tested the "non relinked" tables in a older version of the DB and confirmed it is working as intended with no errors
I expect/want to be able to edit records without a write error, but am hesitant to update the other users to the new table if it is currently having write errors
After changing the schema of a linked table, it's required to refresh the link on all Access databases connected to it.
You can do this on the ribbon through external data -> linked table manager.
Unfortunately, either all users that have a database need to do this manually, unless you automate the task on startup through vba.
You have two separate issues. To "see" new columns, then yes, you must re-link the tables.
(so above is separate question and separate issue). You thus as a general rule can add new columns to the database (even while in use). However, the client side linked tables will not see the new columns until such time you re-link. This approach (adding new columns, but not yet re-linked from Access) is certainly ok and fine - the only downside is end users can't see nor use the new columns until such time you link. From a developer point of view, this good - since your users will not see nor find new columns until such time you roll out a new front end to each work station.
Ok, now problem and issue number two.
As for adding a new column, then re-linking, and THEN having some issue is really a separate issue. In most cases, if you attempting to use a tiny int as a Boolean (and I think that is your case), then you need to ensure several things:
Do not allow nulls (you seem to have this ok).
Make sure you set a default of 0 (server side) for this column. (you might have not allowed nulls, but without a default, then Access likely will still complain. And this default is important during creating time - since the new column needs to be "filled" with zeros.
Make sure the table has a PK defined.
Consider adding a row version column (I think mySQL has these, not sure but they can help immensely).
I'm wondering if there is any better way than going through the tables one by one adding the columns missing when some fields/tables needs to be added because of the most recent changes in the app?
For example, I'm working at the localhost and when I finish doing the new version of my app, I will put all the files into my FTP and, sometimes, I have done, in my local database, changes and so it means that I also need to update my database at my server.
There's any better way to add/edit the columns/tables without changing the info? Some of the columns are also deleted, etc.
Hopefully you've thought your database design through so that making changes to the structure is a rare occurrence. If you're making regular changes to the number of columns or adding tables, it's likely a sign that you haven't normalized your database structure sufficiently.
Anyway, I'd script it as an SQL file that you deploy (which you can then run through phpMyAdmin or the command line or any other means you prefer to execute SQL queries). This has the added advantage of being something you can easily duplicate across your development and production databases, send to customers, and if you wish store in version control so you know when exactly you made the changes to the database.
This way, you'll end up with an SQL file that has a couple of statements like
ALTER TABLE `foo` ADD `new` INT NOT NULL ;
or something similar.
As for how you'd make the file, probably the easiest way is just copying and pasting the generated SQL statement from phpMyAdmin after modifying the table -- the SQL code used to make the change is shown near the top of the screen on the next page. You can copy and paste that to a new text file to create your SQL file. You may wish to add the first line
use `baz`;
using your database name instead of "baz". That way you don't have to specify on import which database the changes are meant for.
Hope this helps.
I have run delete query in my table on my local system
delete from table_name
Now i want to recover it. How can i do this Please help me. I am using php mysql. Please help me
Unfortunately, no. If you were running the server in default config, go get your backups (you have backups, right?) - generally, a database doesn't keep previous versions of your data, or a revision of changes: only the current state.
(Alternately, if you have deleted the data through a custom frontend, it is quite possible that the frontend doesn't actually issue a DELETE: many tables have a is_deleted field or similar, and this is simply toggled by the frontend.
Note that this is a "soft delete" implemented in the frontend app - the data is not actually deleted in such cases; if you actually issued a DELETE, TRUNCATE or a similar SQL command, this is not applicable.
If you try to create a TEXT column on a table, and give it a default value in MySQL, you get an error (on Windows at least). I cannot see any reason why a text column should not have a default value. No explanation is given by the MySQL documentation. It seems illogical to me (and somewhat frustrating, as I want a default value!). Anybody know why this is not allowed?
Windows MySQL v5 throws an error but Linux and other versions only raise a warning. This needs to be fixed. WTF?
Also see an attempt to fix this as bug #19498 in the MySQL Bugtracker:
Bryce Nesbitt on April 4 2008 4:36pm:
On MS Windows the "no DEFAULT" rule is an error, while on other platforms it is often a warning. While not a bug, it's possible to get trapped by this if you write code on a lenient platform, and later run it on a strict platform:
Personally, I do view this as a bug. Searching for "BLOB/TEXT column can't have a default value" returns about 2,940 results on Google. Most of them are reports of incompatibilities when trying to install DB scripts that worked on one system but not others.
I am running into the same problem now on a webapp I'm modifying for one of my clients, originally deployed on Linux MySQL v5.0.83-log. I'm running Windows MySQL v5.1.41. Even trying to use the latest version of phpMyAdmin to extract the database, it doesn't report a default for the text column in question. Yet, when I try running an insert on Windows (that works fine on the Linux deployment) I receive an error of no default on ABC column. I try to recreate the table locally with the obvious default (based on a select of unique values for that column) and end up receiving the oh-so-useful BLOB/TEXT column can't have a default value.
Again, not maintaining basic compatability across platforms is unacceptable and is a bug.
How to disable strict mode in MySQL 5 (Windows):
Edit /my.ini and look for line
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
Replace it with
sql_mode='MYSQL40'
Restart the MySQL service (assuming that it is mysql5)
net stop mysql5
net start mysql5
If you have root/admin access you might be able to execute
mysql_query("SET ##global.sql_mode='MYSQL40'");
Without any deep knowledge of the mySQL engine, I'd say this sounds like a memory saving strategy. I assume the reason is behind this paragraph from the docs:
Each BLOB or TEXT value is represented internally by a separately allocated object. This is in contrast to all other data types, for which storage is allocated once per column when the table is opened.
It seems like pre-filling these column types would lead to memory usage and performance penalties.
As the main question:
Anybody know why this is not allowed?
is still not answered, I did a quick search and found a relatively new addition from a MySQL developer at MySQL Bugs:
[17 Mar 2017 15:11] Ståle Deraas
Posted by developer:
This is indeed a valid feature request, and at first glance it might seem trivial to add. But TEXT/BLOBS values are not stored directly in the record buffer used for reading/updating tables. So it is a bit more complex to assign default values for them.
This is no definite answer, but at least a starting point for the why question.
In the mean time, I'll just code around it and either make the column nullable or explicitly assign a (default '') value for each insert from the application code...
"Support for DEFAULT in TEXT/BLOB columns"
is a
feature request in the MySQL Bugtracker (Bug #21532).
I see I'm not the only one who would like to put a default value in a TEXT column.
I think this feature should be supported in a later version of MySQL.
This can't be fixed in the version 5.0 of MySQL,
because apparently it would cause incompatibility and dataloss if anyone tried to transfer a database back and forth between the (current) databases that don't support that feature and any databases that did support that feature.
You can get the same effect as a default value by using a trigger
create table my_text
(
abc text
);
delimiter //
create trigger mytext_trigger before insert on my_text
for each row
begin
if (NEW.abc is null ) then
set NEW.abc = 'default text';
end if;
end
//
delimiter ;
Support for using expression as default values was added to MySQL 8.0.13, released 2018-10-22, and works for TEXT, JSON, BLOB and GEOMETRY.
You still cannot write :
create table foo(bar text default 'baz')
But you can now write:
create table foo(bar text default ('baz'))
Which achieve the same thing.
I normally run sites on Linux, but I also develop on a local Windows machine. I've run into this problem many times and just fixed the tables when I encountered the problems. I installed an app yesterday to help someone out and of course ran into the problem again. So, I decided it was time to figure out what was going on - and found this thread. I really don't like the idea of changing the sql_mode of the server to an earlier mode (by default), so I came up with a simple (me thinks) solution.
This solution would of course require developers to wrap their table creation scripts to compensate for the MySQL issue running on Windows. You'll see similar concepts in dump files. One BIG caveat is that this could/will cause problems if partitioning is used.
// Store the current sql_mode
mysql_query("set #orig_mode = ##global.sql_mode");
// Set sql_mode to one that won't trigger errors...
mysql_query('set ##global.sql_mode = "MYSQL40"');
/**
* Do table creations here...
*/
// Change it back to original sql_mode
mysql_query('set ##global.sql_mode = #orig_mode');
That's about it.
For Ubuntu 16.04:
How to disable strict mode in MySQL 5.7:
Edit file /etc/mysql/mysql.conf.d/mysqld.cnf
If below line exists in mysql.cnf
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
Then Replace it with
sql_mode='MYSQL40'
Otherwise
Just add below line in mysqld.cnf
sql_mode='MYSQL40'
This resolved problem.
This is a very old question but still it doesn't seems to have been answered properly. And, my this answer isn't actual answer to the question - "WHY can't a text column have a default value", but as it isn't possible to write long text in comment, and as my comment could help someone to prevent the error, here it is as a separate answer:
Some are saying that the error is occurring because of OS - Windows-Linux; but this isn't directly related to OS. (However, there may be differences in default settings of MySQL within different installers for different OSes, I am not sure.)
The main reason is the flag STRICT_TRANS_TABLES for sql_mode setting. if a value is not specified in INSERT statement for TEXT datatype column and if the flag exist in the sql_mode setting then MySQL is reporting an error; and if the flag doesn't exist then MySQL is only reporting a warning and inserts the record.
So, to prevent this error, one can remove the STRICT_TRANS_TABLES from sql_mode setting of MySQL. (He my need to reset the mode to the previous value if it can affect other operations on the database.)
According to the documentation of SQL mode in MySQL ...
For STRICT_TRANS_TABLES, MySQL converts an invalid value to the closest valid value for the column and inserts the adjusted value. If a value is missing, MySQL inserts the implicit default value for the column data type. In either case, MySQL generates a warning rather than an error and continues processing the statement. Implicit defaults are described in Section 11.6, “Data Type Default Values”.
... and documentation of Data Type Default Values ...
The BLOB, TEXT, GEOMETRY, and JSON data types cannot be assigned a default value.
... TEXT column can not have a default value, but if STRICT_TRANS_TABLES is removed from sql_mode then MySQL inserts empty string '' if no value is specified for TEXT column in INSERT statement.
I have been charged with maintaining a legacy classic ASP application. The application uses an ODBC system DSN to connect to a MySQL database.
We had to recently update the servers to satisfy some licencing requirements. We were on Windows, with MySQL 4.x and the 3.51 ODBC driver. We moved to a Linux machine running MySQL 5.1.43 and are running the 5.1.6 ODBC driver on the new IIS server.
Users almost instantly started reporting errors as such:
Row cannot be located for updating.
Some values may have been changed
since it was last read.
This is a ghost error, and the same data changes, on the same record, at a different time won't always produce the error. It is also intermittent between different records, as in, sometimes, no matter what values I plug in, I haven't been able to repro the defect on all records.
It is happening across 70 of about 120 scripts, many over 1,000 lines long.
The only consistency I can find is that on all of the scripts that fail, they are all reading/writing floats to the DB. Fields that have a null value don't seem to crash, but if there is a value like '19' in the database (note the no decimal places) that seems to fail, whereas, '19.00' does not. Most floats are defined as 11,2.
The scripts are using ADODB and recordsets. Updates are done with the following pattern:
select * from table where ID =
udpdated recordID
update properties of the record from the form
call RecordSet.Update and RecordSet.Close
The error is generated from the RecordSet.Update command.
I have created a workaround, where rather than select/copy/update I generate an SQL statement that I execute. This works flawlessly (obviously, an UPDATE statement with a where clause is more focused and doesn't consider fields not updated), so I have a pretty good feeling that it is a rounding issue with the floats that is causing a mis-match with the re-retrieval of the record on the update call.
I really would prefer NOT re-writing 100's of these instances (a grep across the source directly finds 280+ update calls).
Can anyone confirm that the issue here is related to floats/rounding?
And if so, is there a global fix I can apply?
Thanks in advance,
-jc
Have a look at MySQL Forums :: ODBC :: Row cannot be located for updating.
They seem to have found some workaround and some explanations as well..
I ran into a similar issue with a VBA macro utilizing 4.1. When upgraded to 5 errors started popping up.
For me the issue was that values being returned to VBA from MySQL was in a unhandled (by VBA) decimal format.
A CAST on the numbers when querying helped to fix the issue.
So for your issue perhaps the ODBC/ASP combination is recording/reading values differently then what you might expect them to be.