sql_statements.md

Fix Error cannot connet to sqlexpress

• goto service
• find Sql Server Agent
• turn it on

Create database Company with:

• Employee(Id, Name, FullName, BirthDay, Gender, Address, Salary, LeaderId, DepartmentId)

– Department(DepartmentId, DepartmentName, Leader)

– DEAN(MADA, TENDA, DD_DA, PHONG)

– THANNHAN(MANV, TEN_TN, NS, GT, QUANHE)

– NV_DEAN(MANV, MADA, SOGIO)

– PHONGBAN_DD(MAPB, DD)

Create database

• Syntax:

CREATE DATABASE <DatabaseName>

• Example:

CREATE DATABASE Company

Create table in database

• Syntax:

CREATE TABLE <TableName>
(
  ColumnName1 data_type(size),
  ColumnName2 data_type(size),  
  ColumnName3 data_type(size),
  ....
)

• Example: create table Employee(Id, Name, FullName, BirthDay, Gender, Address, Salary, LeaderId, DepartmentId)

CREATE TABLE Employee
(
  Id char(10),
  Name nchar(10),
  FullName nchar(30),
  BirthDay datetime,
  Gender nchar(10) check (Gender in (N'male', N'female')),
  Address nchar(50),
  Salary int default 5000,
  LeaderId char(10),
  DepartmentId char(10),
  primary key (Id)
)

Change column in table

not null

• Syntax:

ALTER TABLE <TableName>
ALTER COLUMN <ColumnName> datatype not null

• Example:

ALTER TABLE Employee
ALTER COLUMN Name nchar(10) not null

SQL PRIMARY KEY Constraint on ALTER TABLE