In SQL Server CE, foreign key constraints on nvarchar fields are only enforced after dropping the trailing whitespace. This means that if the PK is "foo " I can insert "foo" into the FK. Why is this the case? It seems to badly undermine the data integrity the foreign key system is supposed to provide. Is there any way to enforce a forei...
Let me state a simple example: You have an Order and a Shopping Cart. One way I envision persisting this is to save an Order document and a Cart document. The Order document could have a field called "shopping-cart" whose value is the UUID of the relevant Cart document. Another way I can imagine doing this is to save an Order document wi...
Hi guys I have the following structure SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO"; CREATE TABLE IF NOT EXISTS `sis_param_tax` ( `id` int(5) NOT NULL auto_increment, `description` varchar(50) NOT NULL, `code` varchar(5) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=7; CREATE TABLE IF NOT EXISTS ...
Assume I have a two tables, A and B. Table A has a primary Key called A_ID of type int, and table B has a foreign key called A_ID. When I add the two tables to a Linq To SQL data context class it correctly creates the classes and the association between them. My question is, class B will have a property of type int called A_ID. I...
I want to insert the product in the product table but the product table is also having a category Id which is the foreign key ,How will I insert the foreign key through code please tell me. i have used this syntax NewItemToInsert.tbl_PRODUCT_CATEGORY.category_id = Convert.ToInt32 (categoryId); Categories are displayed in the dropdown...
I am using phpMyAdmin. In order to set up a foreign key constraint with InnoDB (under the "Relation View" link on the Structure tab) it appears that I need to add an index for the field to which I want to add the restraint. This obviously has an impact on performance of inserts/updates on the table, particularly if there are several cons...
The method or operation is not permitted. I assume this is a permission's issue, but I can't figure out where I would change it. It is strange because I can rename an index with no issue. EDIT: If you're looking at a table, and you see "Columns, Keys, Constraints, etc.", this is under Keys, and it is the system name that I presu...
I know what they are my question is, how do you link them or are they automatically linked when you have identical names in different tables. Here is an example: Say I have an [orders] table and a [customer] table. Each row in the [orders] table has a customer_id number which is associated with the customer_id in the [customer] table....
I want to create a database with 3 tables. One for posts and one for tags and one that links posts to tags with the post_id and tag_id functioning as foreign key references. Can you explain what an Index would be in this scenario and how it differs from a Foreign Key and how that impacts my database design? ...
I'm trying to use foreign keys properly to maintain data integrity. I'm not really a database guy so I'm wondering if there is some general design principle I don't know about. Here's an example of what I'm trying to do: Say you want to build a database of vehicles with Type (car, truck, etc.), Make, and Model. A user has to input at le...
When I'm trying to create a foreign key linked to a primary key in another table I get: #1452 - Cannot add or update a child row: a foreign key constraint fails (`fayer`.`#sql-225c_1d3`, CONSTRAINT `#sql-225c_1d3_ibfk_1` FOREIGN KEY (`country_id`) REFERENCES `countries` (`id`) ON DELETE CASCADE) I have checked that all tables are usin...
What is the best way in PHP to handle foreign key exceptions on a mysql database? Is there a mysql class that can be used to simplify any code? Ideally, what I want to do, as an example, is to try to delete a record where it is the foreign key parent to any number of child tables. The foreign key throws the exception, so then I would li...
Background: today, an issue arose while using SQL Server Reporting Services. It seems that SSRS drop-down parameters in the report viewer don't allow you to indicate a (null) option so that you can see a report where that parameter is null. Basically, table A is a table nullably referencing table B; since the report uses table B to popul...
I having trouble creating a foreign key in sql 2005. my primary key table has a primary key that spans 2 columns. I want to create my foreign key so it references a column in my primary table but I want to specify a static value for the second column - is this possible? ...
Hello I need to add a Column "CurrentLifeCycleId" [int] into 73 tables and also add a Foreign Key from this new column to another single table "LifeCycle" Id column...is there a simple way I can do this in a few statements rather than go through each table one by one. The column does not need to start off being NULL as I will delete al...
If I want to delete all the tables in my database like this, will it take care of the foreign key constraint? If not, how do I take care of that first? GO IF OBJECT_ID('dbo.[Course]','U') IS NOT NULL DROP TABLE dbo.[Course] GO IF OBJECT_ID('dbo.[Student]','U') IS NOT NULL DROP TABLE dbo.[Student] ...
Hello, I need to perform an ON DELETE CASCADE on my table named CATEGORY, which has the following columls CAT_ID (BIGINT) NAME (VARCHAR) PARENT_CAT_ID (BIGINT) PARENT_CAT_ID is a FK on CAT_ID. Obviously, the lovely SQL Server does not let me use ON DELETE CASCADE claiming circular or multiple paths to deletion. A solution that I see o...
Hi guys Short Question: Basically I am trying to add a scalar property to my entity which holds the ID of a FK entity. What I have tried to do thus far: What I have tried so far is adding the scalar property (called ChildId) and mapped it to the matching column in the database. Now as you can imagine I get some exceptions when I tr...
Let say I have a request table, that looks as follows: RequestId INT ReferenceNumber VARCHAR Each request is logged in a requestlog table. There are no foreign keys between the tables: RequestLogId INT ReferenceNumber VARCHAR Content VARCHAR The requestlog contains the content of the request, and this content needs to be stor...
Hi, i recently migrated my whole DB from myisam to innodb. I am fairly new to all this so i have a question regarding the use of the foreign key. Lets say i have two tables: users, messages. users id (pr_key) name messages id (pr_key) user_id message The id fields are both auto incremented. So now in my queries i join th...