в 13:46, 26 мая 2010

2010-05-26T13:46:06Z

Admin: 1 версия

2010-05-26T10:21:20Z

1 версия

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==Add check constaint to only allow positive value==



<source lang="sql">

1> create table employee(
2> ID int,
3> name nvarchar (10),
4> salary int,
5> start_date datetime,
6> city nvarchar (10),
7> region char (1))
8> GO
1>
2> insert into employee (ID, name, salary, start_date, city, region)
3> values (1, "Jason", 40420, "02/01/94", "New York", "W")
4> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (2, "Robert",14420, "01/02/95", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (4, "Linda", 40620, "11/04/97", "New York", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (5, "David", 80026, "10/05/98", "Vancouver","W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (6, "James", 70060, "09/06/99", "Toronto", "N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (7, "Alison",90620, "08/07/00", "New York", "W")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N")
3> GO
(1 rows affected)
1> insert into employee (ID, name, salary, start_date, city, region)
2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W")
3> GO
(1 rows affected)
1>
2> select * from employee
3> GO
ID name salary start_date city region
----------- ---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W
2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N
3 Celia 24020 1996-12-03 00:00:00.000 Toronto W
4 Linda 40620 1997-11-04 00:00:00.000 New York N
5 David 80026 1998-10-05 00:00:00.000 Vancouver W
6 James 70060 1999-09-06 00:00:00.000 Toronto N
7 Alison 90620 2000-08-07 00:00:00.000 New York W
8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N
9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected)
1>
2> /*
3~ When the salary column is updated the value will be positive
4~ */
5> ALTER TABLE Employee WITH NOCHECK ADD CONSTRAINT
6> MyCheckName CHECK (([salary] >= 0))
7> GO
1>
2> INSERT employee (Name, salary) VALUES ("Bedford", -100)
3> GO
Msg 547, Level 16, State 1, Server sqle\SQLEXPRESS, Line 2
The INSERT statement conflicted with the CHECK constraint "MyCheckName". The conflict occurred in database "master", table "dbo.employee", column "salary".
The statement has been terminated.
1>
2> select * from employee
3> GO
ID name salary start_date city region
----------- ---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W
2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N
3 Celia 24020 1996-12-03 00:00:00.000 Toronto W
4 Linda 40620 1997-11-04 00:00:00.000 New York N
5 David 80026 1998-10-05 00:00:00.000 Vancouver W
6 James 70060 1999-09-06 00:00:00.000 Toronto N
7 Alison 90620 2000-08-07 00:00:00.000 New York W
8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N
9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected)
1>
2>
3> drop table employee
4> GO
1>

</source>

==CHECK Constraints for current date==



<source lang="sql">

3>
4>
5> CREATE TABLE Customers
6> (
7> CustomerNo int IDENTITY NOT NULL
8> PRIMARY KEY,
9> CustomerName varchar(30) NOT NULL,
10> Address1 varchar(30) NOT NULL,
11> Address2 varchar(30) NOT NULL,
12> City varchar(20) NOT NULL,
13> State char(2) NOT NULL,
14> Zip varchar(10) NOT NULL,
15> Contact varchar(25) NOT NULL,
16> Phone char(15) NOT NULL,
17> FedIDNo varchar(9) NOT NULL,
18> DateInSystem smalldatetime NOT NULL
19> )
20> GO
1>
2> ALTER TABLE Customers
3> ADD CONSTRAINT CN_CustomerDateInSystem
4> CHECK
5> (DateInSystem <= GETDATE ())
6> GO
1>
2> drop table Customers;
3> GO
</source>

==Check the value range==



<source lang="sql">

22>
23> CREATE TABLE MySavings(AccountNum Int NOT NULL,
24> Amount Money NOT NULL)
25>
26> CREATE TABLE MyChecking(AccountNum Int NOT NULL,
27> Amount Money NOT NULL)
28>
29> ALTER TABLE MyChecking ADD CONSTRAINT ckMinBalance
30> CHECK (Amount > $100.00)
31>
32> INSERT MySavings VALUES (12345, $1000.00)
33>
34> INSERT MyChecking VALUES (12345, $1000.00)
35> GO
(1 rows affected)
(1 rows affected)
1> select * from mysavings
2> go
AccountNum Amount
----------- ---------------------
12345 1000.0000
(1 rows affected)
1>
2> select * from mychecking
3> GO
AccountNum Amount
----------- ---------------------
12345 1000.0000
(1 rows affected)
1>
2> BEGIN TRANSACTION
3>
4> UPDATE MyChecking SET Amount = Amount - $990.00
5> WHERE AccountNum = 12345
6>
7> UPDATE MySavings SET Amount = Amount + $990.00
8> WHERE AccountNum = 12345
9>
10> COMMIT TRANSACTION
11> GO
Msg 547, Level 16, State 1, Server sqle\SQLEXPRESS, Line 4
The UPDATE statement conflicted with the CHECK constraint "ckMinBalance". The conflict occurred in database "master", table "dbo.MyChecking",
The statement has been terminated.
(1 rows affected)
1>
2>
3> drop table MySavings
4> drop table MyChecking
5> GO
1>
2>

</source>

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SQL Server/T-SQL/Constraints/Check value range - История изменений

в 13:46, 26 мая 2010

Admin: 1 версия