test.examples_set_constraint source code

1 /**
2 The following examples come from
3 $(LINK http://zetcode.com/databases/mysqltutorial/constraints/).
4  */
5 module test.examples_set_constraint;
6 
7 version(D_Ddoc)
8 {
9     ///
10     class BlankClassSoDocsWillBeGenerated { }
11 }
12 
13 
14 /**
15 This example is for the SET constraints. The table
16 in SQL can be created by
17 $(D $(D $(D sql
18 CREATE TABLE Students
19 (
20     Id INTEGER NOT NULL PRIMARY KEY,
21     Name VARCHAR(55),
22     Certificates SET('A1', 'A2', 'B1', 'C1')
23 );
24 
25 )))
26  */
27 unittest
28 {
29     import db_constraints;
30 
31     class Student
32     {
33         private int _Id;
34         @PrimaryKeyColumn @NotNull
35         @property int Id()
36         {
37             return _Id;
38         }
39         @property void Id(int value)
40         {
41             setter(_Id, value);
42         }
43         private string _Name;
44         @property string Name()
45         {
46             return _Name;
47         }
48         @property void Name(string value)
49         {
50             setter(_Name, value);
51         }
52         private string _Certificates;
53         // Certificates can only have values that
54         // are among the set below.
55         @SetConstraint!("A1", "A2", "B1", "C1")
56         @property string Certificates()
57         {
58             return _Certificates;
59         }
60         @property void Certificates(string value)
61         {
62             setter(_Certificates, value);
63         }
64         this(int Id_, string Name_, string Certificates_)
65         {
66             this._Id = Id_;
67             this._Name = Name_;
68             this._Certificates = Certificates_;
69             initializeKeyedItem();
70         }
71 
72         mixin KeyedItem!();
73     }
74 
75     // A1 and B1 are both allowed in the set so no error is raise here
76     auto paul = new Student(1, "Paul", "A1,B1");
77     // we can see paul's certificates are the same as they came in
78     assert(paul.Certificates == "A1,B1");
79 
80     // all of jane's certificates are acceptable but not in order
81     auto jane = new Student(2, "Jane", "A1,B1,A2");
82     // the set constraint sorts the certificates for you
83     assert(jane.Certificates == "A1,A2,B1");
84 
85     // now lets try with some duplicates
86     jane.Certificates = "A1,A2,B1,A1";
87     // the set constraint will also remove duplicates
88     assert(jane.Certificates == "A1,A2,B1");
89 
90     // if we enter in certificates that are not allowed we should expect an exception
91     import std.exception : assertThrown;
92     assertThrown!CheckConstraintException(new Student(3, "Mark", "A1,A2,D1,D2"));
93 }