constraints

Hello The following procedure will have to move all constraints from one table to the other however I am having some difficulties at the point where the constraint should be deleted. The problem: how do I use variables in the following line ALTER TABLE var_referenced_table_name DROP FOREIGN KEY var_constraint_name; when I use as is, I receive the following error Error Code: 1146. Table 'oaf_businesslink_dev.var_referenced_table_name' doesn't exist MySQL does not recognise var_referenced_table_name and var_constraint_name as variables. DELIMITER // DROP PROCEDURE IF EXISTS AlterConstraints//

Rules (Transact-SQL)[1] are reusable what permitted to overcome the shortcoming of non-re-usability of check constraints. And now I read [1] that: "This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. We recommend that you use check constraints instead. Check constraints are created by using the CHECK keyword of CREATE TABLE or ALTER TABLE" So, what is instead of rules and why are they deprecated? ==== Update: AlexKuznetsov, are table-level check constraints

Possible Duplicate: No type inference with generic extension method Consider two methods: public static IEnumerable<V> Merge<V> (this IEnumerable<IEnumerable<V>> coll) public static IEnumerable<V> Merge<T, V> (this IEnumerable<T> coll) where T : IEnumerable<V> Both compile just fine, in both cases the type of generic types will be known at compile time of caller, and thus the exact type of extended type. You can call both fine, but only the first one as extension. Why? Update 1 To see it fail, use the second method and such example: var x = new List<List<int>>(); var y = x.Merge(); Update --

Suppose I have the following tables CREATE TABLE plugins ( id int primary key, type text); insert into plugins values (1,'matrix'); insert into plugins values (2,'matrix'); insert into plugins values (3,'function'); insert into plugins values (4,'function'); CREATE TABLE matrix_params ( id int primary key, pluginid int references plugins (id) ); This all works as expected but I would like to add an additional constraint that a matrix_param can only refer to the pluginid that has type 'matrix'. So insert into matrix_params values (1,1); Should succeed but insert into matrix_params values (2,3);

So I was just reading about Exclusion Constraints in PostgreSQL and I couldn't seem to find a way to use bitwise operators on bitstrings, and I was wondering if it was possible. My use case is I have a name: text column and a value: bit(8) column. And I wanted to create a constraint that basically says this: ADD CONSTRAINT route_method_overlap EXCLUDE USING gist(name WITH =, value WITH &) But this doesn't work since operator &(bit,bit) is not a member of operator family "gist_bit_ops" I assume this is because the bit_ops & operator doesn't return a boolean. But is there a way to do what I'm

I'm trying to create a constraint on the OE.PRODUCT_INFORMATION table which is delivered with Oracle 11g R2. The constraint should make the PRODUCT_NAME unique. I've tried it with the following statement: ALTER TABLE PRODUCT_INFORMATION ADD CONSTRAINT PRINF_NAME_UNIQUE UNIQUE (PRODUCT_NAME); The problem is, that in the OE.PRODUCT_INFORMATION there are already product names which currently exist more than twice. Executing the code above throws the following error: an alter table validating constraint failed because the table has duplicate key values. Is there a possibility that a new created