constraints

问题 I don't need to execute duplicatation query like checking some column is unique or not because this operation always execute with SQL Server constraint. However, default error message from SQL Server is not well-defined for end-user. Do you have any idea for change/redefine error message to be more user-friendly? PS. I execute all query via Entity Framework 4.0. 回答1: The only way I know to do this is to catch SqlException and then check the Number property. This property is a short-cut to the

问题 I have two domain classes. One is : class User { String login String password String firstName String lastName String address String email static constraints = { login blank:false, size:5..15,matches:/[\S]+/, unique:true password blank:false, size:5..15,matches:/[\S]+/ firstName blank:false lastName blank:false email email: true } } And other is class AddWebsite { String website User user static constraints = { website blank:false website(unique: ['user']) } } I am working with MongoDB at the

问题 My UIView's are stacking up on top of each other like so : Each UIView is inside a wordContainer . Each UIView has two UILabel 's inside of it I create each individual UIView with two child UILabel's like so : var labels = [UIView]() for word in words { let wordLabel = UILabel(frame: CGRectZero) wordLabel.text = word.valueForKey("sanskrit") as? String wordLabel.numberOfLines = 0 wordLabel.sizeToFit() wordLabel.translatesAutoresizingMaskIntoConstraints = false let englishWordLabel = UILabel

问题 I've been trying for 2 days in a row to fix a custom cell I created. I'm new to iOS, so I've been reading that I must set constraint if use autolayout is enabled. Even though I set some constraints, the issue is still there, so I'm guessing either ways the iOS Simulator has a bug I'm not aware of, or there was something missing in the 10+ guides & tutorials I have already read. Yes, I made my research, I've read several articles including: Using Auto Layout in UITableView for dynamic cell

问题 I am trying to make a table in Oracle which is governed by several integrity constraints. The table consists of a hypothetical student database. One of the rules of the database is that for a student to be classified as a junior, they must have completed between 55 and 84 credit hours (inclusive). I need to create an integrity constraint to enforce this rule but am not entirely sure how to go about doing it. I have a feeling that a CHECK constraint would be useful in this situation. So far I

问题 I'm having a table (an existing table with data in it) and that table has a column UserName. I want this UserName to be unique. So I add a constraint like this: ALTER TABLE Users ADD CONSTRAINT [IX_UniqueUserUserName] UNIQUE NONCLUSTERED ([UserName]) Now I keep getting the Error that duplicate users exist in this table. But I have checked the database using the following query: SELECT COUNT(UserId) as NumberOfUsers, UserName FROM Users GROUP BY UserName, UserId ORDER BY UserName This results

问题 The consumer interfaces in MassTransit all expect the message models to be classes and not structs. Since they are all inner interfaces (very nice design there I must say), this is the generic container class showing the constraint, taken directly from the source code: /// <summary> /// Declares a Consume method for the message type TMessage which is called /// whenever a a message is received of the specified type. /// </summary> public static class Consumes<TMessage> where TMessage : class

问题 I am currently trying to insert data into a table called "customer_quote" , this table acts as a linking table between the "customer" table and the "customer_tariffs" table. It also records the user who sumbitted the data via the "user" table. Here is a schema of my db: http://i.imgur.com/LOG1T.png and here is a screenshot of the table that is not allowing me to insert into it. http://i.imgur.com/i2wiU.png This is the process in how I insert into my db: Insert data into customer table

问题 i have an assignment that i have to do in SQL Server Manager. I have a database, and a table named User . Under user there are a column named e-mail . The assignment is to create a new constraint to that table that affect the column e-mail. There has to be only one ' @ ' and minimum one ' . ' It is not allowed to be any special characters such as ( ! , " , # , ¤ , % , etc.) <- this do not include the '@' and '.' I've tried some different things but cant seem to make it work. Also it should be

问题 I would like to build a Google OR Tools model to use linear_solver for a CBC_MIXED_INTEGER_PROGRAMMING . Following Google tutorial I learned hot to build the constraints but I have a question... is it necessary to hand write every constraint? I mean, I have the following DataFrame df_constraint which contain the coefficient of the constraints in the form of ax+by<=c . +---+---+---+ | A | B | C | +---+---+---+ | 1 | 5 | 7 | | 2 | 9 | 3 | | 3 | 0 | 4 | +---+---+---+ the table could be