Giáo trình SQL bài 3

non-Unicode, 16 bytes pointer on row, preferred over text data type 0-2 GB varcharmax non-Unicode 0-8000 varchar[n] non-Unicode 0-8000 char[n] Comments Bytes Name... Example 1CREATE TABL

Lab 01b

Data types (1)

n Integer

0 to 255 1

tinyint

-215 (-32,768) to 215 - 1 (32,767) 2

smallint

-231 (-2,147,483,648) to

231 - 1 (2,147,483,647)

4 int

-263 (-9,223,372,036,854,775,808) to

263 - 1 (9,223,372,036,854,775,807)

8 bigint

Range Bytes

Name

Data types (2)

n Exact numeric

- 1038 +1 to 1038 - 1

5 – 17 numeric[p[,s]]

- 1038 +1 to 1038 - 1

5 – 17 decimal[p[,s]]

Range Bytes

Name

p (precision)

The maximum total number of decimal digits that can be stored, both to the left and

to the right of the decimal point The precision must be a value from 1 through the maximum precision of 38 The default precision is 18.

s (scale)

- 1.79E+308 to -2.23E-308,

0 and 2.23E-308 to 1.79E+308

n Float[(n)]

Range Bytes

Name

Data types (4)

n Monetary

- 214,748.3648 to 214,748.3647

4 smallmoney

-922,337,203,685,477.5808 to 922,337,203,685,477.5807

8 Money

Range Bytes

Name

Data types (5)

n Date and Time

January 1, 1900, to June 6, 2079

4 smalldatetime

January 1, 1753, to December 31, 9999

8 datetime

Range Bytes

Name

non-Unicode, 16 bytes pointer on row, preferred over text data type

0-2 GB varchar(max)

non-Unicode 0-8000

varchar[(n)]

non-Unicode 0-8000

char[(n)]

Comments Bytes

Name

16 bytes pointer or in row, preferred over ntext data type

0-2 GB nvarchar(max)

max 4000 unicode characters 0-8000

Name

0-8000 varbinary[(n)]

0-8000 binary[(n)]

Comments Bytes

Name

Comments Bytes

Name

n Global identifier

16 uniqueidentifier

Comments Bytes

Name

16 bytes pointer 0-2GB

xml

Comments Bytes

Name

Data types (10)

n Special

0-8016 sql_variant

table

-256 sysname

one column per table 8

timestamp

0-8 cursor

1 byte for every 8 bit columns 1

bit

Range Bytes

Name

n Create table

n Alter table

n Drop table

[ NULL | NOT NULL ]

[ [ CONSTRAINT constraint_name ] DEFAULT constant_expression ]

| [ IDENTITY [ ( seed ,increment ) ] [ NOT FOR REPLICATION ] ]

Create Table (1)

< column_constraint > ::=

[ CONSTRAINT constraint_name ]

{ { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ] |

[ FOREIGN KEY ] REFERENCES referenced_table_name [ ( ref_column ) ]

[ ON DELETE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ]

| CHECK ( logical_expression )

}

Create table (3)

< table_constraint > ::=

[ CONSTRAINT constraint_name ]

{ { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ]

(column [ ASC | DESC ] [ , n ] )

| FOREIGN KEY ( column [ , n ] )

REFERENCES referenced_table_name [ ( ref_column [ , n ] ) ]

[ ON DELETE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ] [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ]

| CHECK ( logical_expression )

}

Example (1)

CREATE TABLE Department

(

DNumber numeric(4,0) Constraint pk_dep Primary Key,

DName varchar(15) not null,

MgrSSN char(9) Constraint fk_dep Foreign Key References

Employee(SSN),

MgrStartdate datetime,

);

Example (2)

Or:

CREATE TABLE Department

(

DNumber numeric(4,0) not null,

DName varchar(15) not null,

MgrSSN char(9),

MgrStartdate datetime,

Constraint pk_dep Primary Key (DNumber),

Constraint fk_dep Foreign Key (MgrSSN) References Employee(SSN)

);

Alter Table

ALTER TABLE table_name

{ ALTER COLUMN column_name

{ type_name [ ( { precision [ , scale ] } ) ]

[ NULL | NOT NULL ] | {ADD | DROP }

Example (1)

Column

ALTER TABLE Department ADD column_b

VARCHAR(20) NULL ;

ALTER TABLE Department DROP column_b;

ALTER TABLE Department ALTER COLUMN

Example (2)

Table

n Primary key

ALTER TABLE Department

ADD Constraint pk_dept PRIMARY KEY (DNumber);

n Foreign key

ALTER TABLE Department

ADD Constraint fk_dept Foreign Key (MgrSSN) References

Employee(SSN);

Drop Constraint

ALTER TABLE Department

n Insert

n Delete

Insert into table_name [(column_list)]

Values (value_list)

Example

INSERT INTO Department

VALUES (5, 'Research', '333445555', '22-MAY-78');

Or

INSERT INTO Department (DNumber, DName)

VALUES (5, 'Research');

n Create Database company (13th slide)

n Insert Data

Practice: Create table (1)

n Department

CREATE TABLE Department(

DName varchar(15) NOT NULL, DNumber numeric(4, 0) NOT NULL, MgrSsn char(9) NULL,

MgrStartdate datetime NULL) GO

Practice: Create table (2)

n Employee

CREATE TABLE Employee(

FName varchar(15) NOT NULL, MInit varchar(1) NULL,

LName varchar(15) NOT NULL, SSN char(9) NOT NULL,

BDate datetime NULL, Address varchar(30) NULL, Sex char(1) NULL,

Salary numeric(10, 2) NULL,

Practice: Create Primary Key

ALTER TABLE Department

ADD Constraint pk_Dept PRIMARY KEY (DNumber) GO

ALTER TABLE Employee

ADD Constraint pk_Emp PRIMARY KEY (SSN) GO

Practice: Create Foreign Key

n Department

ALTER TABLE Department

ADD constraint fk_DeptMgrssn FOREIGN KEY(Mgrssn) REFERENCES Employee(SSN)

GO

n Employee

ALTER TABLE Employee

ADD Constraint fk_EmpDNo FOREIGN KEY(DNo) REFERENCES Department(DNumber)

GO

Practice: Insert Data (1)

n Department

INSERT INTO Department

VALUES ('Research', 5, Null, '22-MAY-1978') GO

INSERT INTO Department

VALUES ('Administration', 4, Null, '01-JAN-1985') GO

INSERT INTO Department

VALUES ('Headquarters', 1, Null, '19-JUN-1971') GO

Practice: Insert Data (2)

n Employee

INSERT INTO Employee

VALUES ('James', 'E', 'Borg', '888665555', '10-NOV-1927', 'Houston,TX', 'M', 55000, null, 1)

GO

INSERT INTO Employee

VALUES ('Franklin', 'T', 'Wong', '333445555', '08-DEC-1945', 'Houston,TX', 'M', 40000, '888665555', null, 5)

GO

INSERT INTO Employee

VALUES ('Jennifer', 'S', 'Wallace', '987654321', '20-JUN-1931', 'Bellaire,TX', 'F', 43000, '888665555', null, 4)

Practice: Insert Data (3)

n Employee

INSERT INTO Employee

VALUES ('John', 'B', 'Smith', '123456789', '09-Jan-1955', 'Houston,TX', 'M', 30000, '333445555', 5)

GO

INSERT INTO Employee

VALUES ('Alicia', 'J', 'Zelaya', '999887777', '19-JUL-1958', 'Spring,TX', 'F', 25000, '987654321', 4)

GO

INSERT INTO Employee

VALUES ('Ramesh', 'K', 'Narayan', '666884444', '15-SEP-1952', 'Humble,TX', 'M', 38000, '333445555', 5)

GO

INSERT INTO Employee

VALUES ('Joyce', 'A', 'English', '453453453', '31-JUL-1962', 'Houston, TX', 'F', 25000, '333445555', 5)

GO

INSERT INTO Employee

VALUES ('Ahmad', 'V', 'Jabbar', '987987987', '29-MAR-1959', 'Houston,TX', 'M', 25000, '987654321', 4)

GO

Practice: Update date

UPDATE Department

SET MgrSsn = '333445555' WHERE DNumber = 5

GO

UPDATE Employee

SET MgrSsn = '987654321' WHERE DNumber = 4

Practice: Query Data

Practice: Delete Table

n Delete Foreign Key:

ALTER TABLE Employee Drop Constraint FK_EmpDNo

Practice: Delete Table (2)