How to remove constraints from my MySQL table?
Mysql has a special syntax for dropping foreign key constraints: ALTER TABLE tbl_magazine_issue DROP FOREIGN KEY FK_tbl_magazine_issue_mst_users
constraints
Unique Key constraints for multiple columns in Entity Framework
With Entity Framework 6.1, you can now do this: [Index(“IX_FirstAndSecond”, 1, IsUnique = true)] public int FirstColumn { get; set; } [Index(“IX_FirstAndSecond”, 2, IsUnique = true)] public int SecondColumn { get; set; } The second parameter in the attribute is where you can specify the order of the columns in the index. More information: MSDN
Techniques for Tracing Constraints
First of all, your function has the wrong type; I am pretty sure it should be (without the context) a -> (a -> b) -> b. GHC 7.10 is somewhat more helpful in pointing that out, because with your original code, it complains about a missing constraint Internal (a -> b) ~ (Internal a -> … Read more
Is there a constraint that restricts my generic method to numeric types?
C# does not support this. Hejlsberg has described the reasons for not implementing the feature in an interview with Bruce Eckel: And it’s not clear that the added complexity is worth the small yield that you get. If something you want to do is not directly supported in the constraint system, you can do it … Read more
How to truncate a foreign key constrained table?
Yes you can: SET FOREIGN_KEY_CHECKS = 0; TRUNCATE table1; TRUNCATE table2; SET FOREIGN_KEY_CHECKS = 1; With these statements, you risk letting in rows into your tables that do not adhere to the FOREIGN KEY constraints.
How can foreign key constraints be temporarily disabled using T-SQL?
If you want to disable all constraints in the database just run this code: — disable all constraints EXEC sp_MSforeachtable “ALTER TABLE ? NOCHECK CONSTRAINT all” To switch them back on, run: (the print is optional of course and it is just listing the tables) — enable all constraints exec sp_MSforeachtable @command1=”print ‘?'”, @command2=”ALTER TABLE … Read more