I want ask that, is there any easy way to synchronize mysql table fields?
Let me extend my question:
I have a mysql database driven site, and I want to use my table for more than one content provider (I can use only one table because of hosting features) by separating table prefix (like Wordpress does).
I need a way to copy all fields from current table and add a prefix (I'll specify) to all new entries (E.g : there are 2 fields, links, pages and I want to add new fields new_links, new_pages to current table automatically / all keys must be the same (I mean field id's, values etc..)).
After creating those fields, there should be a way to control that, if one or more new entry was added to original fields then new fields should be created in prefixed (new_) fields.
I'm not 100% sure that I'm getting the issue, but...
Adding two new columns to the table shouldn't be a problem:
ALTER TABLE foo ADD COLUMN new_links ...
You could keep them in sync from your application (problematic) or via a trigger.
Definitely time to upgrade hosting providers.
Related
I am working on a web application that is up and running on a production server. I need to make some changes to the database but I am not sure what is the best way to go about this.
I have a table called Trips and it contains columns "maximum_guests", "minimum_guests", etc.
I need to add a column called "base_guests" and I want to give it a value of "maximum_guests" for existing entries in my table(production data). From this point forward Trips will only be created if both "base_guests" and "maximum_guests" are provided.
Is there a safe way to do this? I am using Php Symfony, mysql and doctrine if that helps.
You should first make an export of your database just in case. Then add the column to the table and run.
UPDATE Trips set base_guests = maximum_guests;
This will assign the value of maximum_guests to base_guests for each record in the Trips table.
For the past couple years I've been working on my own lightweight PHP CMS that I use for my personal projects. The one thing its missing is an easy databasing solution.
I am looking to create a simple content type database framework in which I can specify a new type (user, book, event..ect) and then be able to load everything related to it automatically.
For some content types, there could be fields that can only have 1 value and some that can have zero to many values so I will use a new table for these. Take the example:
table: event
columns: id, name, description, date
table: event_people:
columns: id_event, id_user
table: event_pictures:
columns: id_event, picture
Events will have a bunch of fields that contain a value such as the description, but there could also be a bunch of pictures and people going to it.
I want to be able to create a generic PHP class that will load all the information on a content type. My current thought process is to make entity loader function that I can give it an id and type:
Entity:load($id, "event");
From this I was going to get all of the tables with the prefix of "event", load all of the data with the passed in ID and then store it in a multidimensional array. I feel like there is probably a more efficient way for this however. I'd like to stay away from having a config file someplace that specifies all of the content types and their child tables because I want to be able to add a new child table and have it pick it up automatically.
Is there anyway to store this relationship directly within the MySQL table? I don't do a lot of databasing and I've just recently started to use foreign keys (what a life saver). Would I be more efficient to see which tables have a foreign key related to the id column in the event table, and if so how would this be done? I'm also open to different ways of storing this information.
Note: I'm doing this just for fun so please don't refer me to use any premade frameworks. I'd like to create this myself.
I think your approach of searching for all tables with prefix name event is sensible. The only way I can think to be more efficient is to have an "entity_relationship" table that you could query. It would allow you flexibility in your naming convention, avoid naming conflicts, and this lookup should be more efficient than a pattern match search.
Then whenever a new object type with its own table was added, then you could make an entry on the relationship table.
INSERT INTO entity_relationship VALUES
('event','event_people'),
('event','event_pictures'),
('event','event_documents'),
('event','event_performers');
I am working on a web application that manages the clients of the company. Details such as phone, address, email and name are saved for each client and there are corresponding fields in the database table where I save these details.
The user of the application has to be able to change the different details. For instance, he might decide that we need an extra field to save the fax number of the client or he may decide that the address field is no longer needed and delete it.
Using NoSql is not a option. I have to use PHP and mySql.
I have been considering using a JSON string to save database table fields but I have not come up with a solution yet.
Is altering the structure of my db table the only solution to my problem? I would like to prevent dynamically altering the structure of the db table, if possible.
Would it be a could idea to implement dynamic views? However, I guess that this would not address the necessity to insert new fields.
Thank you in advance.
Wouldn't it make more sense to have another table, let's call it 'information' which has the user_id as a foreign key?
So you have:
CREATE TABLE user (
user_id ...
/* necessary information */
);
CREATE TABLE information (
user_id ...
information_type /* maybe enum, maybe just string, maybe int, depending how you want to do that */
information_blob
);
You then retrieve the information with JOIN, and do not have to alter the table every time somebody wants to add another bit of info.
What you need a key-value pair system for MySQL. The idea of NoSQL databases is that you can create your own schema based on key/values, using essentially anything for the value.
Create a table special_fields with a field_name column, or something named more specifically to field names. Use this table to define the available field names, and another table to store the client_id and special_field_id and then a value.
So client #1 would have an address (special_field record #1) value of "123 x street"
The only other way I can think of is to actually change the schema of a table to add/remove columns. Don't do that.
At our company we have a business solution which includes CMS, CRM and several other systems.
These are installed in several domains, for each of our clients.
The systems are still in development, so new tables and fields are added to the database.
Each time we want to release a new version to our clients, i have to go through their database and insert the new fields and tables manually.
Is there a way that this could be done automatically(a script maybe that detects the new fields and tables and inserts them?)
We are using php and mysql.
We would like to avoid backing up the clients data, dropping the database tables, running the sql query to insert all the database tables(including the new ones) and then re-inserting the customers data. Is this possible?
Toad for MySQL
DB Extract, Compare-and-Search Utility — Lets you compare two MySQL databases, view the differences, and create the script to update the target.
What you are looking for is
ALTER TABLE 'xyz' ADD 'new_colum' INT(10) DEFAULT '0' NOT NULL;
or if you want to get rid of a colum
ALTER TABLE 'xyz' DROP 'new_colum';
Put all table edits into an update.php file and the either call and delete it once manually or try to select "new_colum" once and update the database when it's not present.
OR what I do: "I have a settingsfield "software version" and use this as a trigger to update my tables.
But since you have to install the new scripts anyways you can just call it manually.
I have a MySQL database where I am storing information that is entered from a PHP web page. I have a page that allows the user to view an existing row, and make changes and save them to the database. I want to know the best way to keep the original entries, as well as the new update and any subsequent updates.
My thought is to make a new table with the same columns as the first, with an additional timestamp field. When a user submits an update, the script would take the contents of the main table's row, and enter them into the archive table with a timestamp when it was done, and then enter in the new values to the main table. I'd also add a new field to the main table to specify whether or not the row has ever been edited.
This way, I can do a query of the main table and get the most current data, and I can also query the archive table to see the change history. Is this the best way to accomplish this, or is there a better way?
You can use triggers on update, delete, or insert to keep track of all changes, who made them and at what time.
Lookup database audit tables. There are several methods, I like the active column which gets set to 0 when you 'delete' or 'update' and the new record gets inserted. It does make a headache for unique key checking. The alternative I've used is the one you have mentioned, a separate table.
As buckbova mentions you can use a trigger to do the secondary insert on 'delete' or 'update'. Otherwise manage it in your PHP code if you don't have that ability.
You don't need a second table. Just have a start and end date on each row. The row without an end date is the active record. I've built entire systems using this method, and just so long as you index the date fields, it's very fast.
When retrieving the current record, AND end_date IS NULL gets added to the WHERE clause.
In this situation, I would recommend you to consider all properties in one table after adding it few columns:
active/ not active
ID of the person who kept these parameters
timestamp of adding