Foreign Language Specialized

8/3/2019 Foreign Language Specialized

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Foreign

Language

Specia

lizedLecturer:

Student

:1.Ngo

Vu

Linh

2. LeVa

nLinh

aTanDat

4.Tra

nQuan

gNhu

5. DangV

anHoai

6.VoN

gocThu

Mr.Duyet


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SQL is a standard language for accessing

and manipulating databases.


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What isSQL?

SQL stands for Structured QueryLanguage

SQL lets you access and manipulate

databases SQL is an ANSI (American National

Standards Institute) standard


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What Can SQLdo?

SQL can execute queries against a database

SQL can retrieve data from a database SQL can insert records in a database SQL can update records in a database SQL can delete records from a database

SQL can create new databases SQL can create new tables in a database SQL can create stored procedures in a database SQL can create views in a database SQL can set permissions on tables, procedures,

and viewsq SQL can be divided into two parts: The Data

Manipulation Language (DML) and the Data

Definition Language (DDL).


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q The query and update commands

form the DML part of SQL:

SELECT- extracts data from a database

UPDATE - updates data in a database

DELETE - deletes data from a database

INSERT INTO - inserts new data into a

database

What Can SQLdo?


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q The DDL part of SQL permits database

tables to be created or deleted. It alsodefines indexes (keys), specifies linksbetween tables, and imposes constraintsbetween tables. The most important DDL

statements in SQL are:

What Can SQLdo?

CREATE DATABASE - creates a new database ALTER DATABASE - modifies a database CREATE TABLE - creates a new table

ALTER TABLE - modifies a table DROP TABLE - deletes a table CREATE INDEX- creates an index (search

key) DROP INDEX- deletes an index


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The SQL SELECT Stateme

q

The SELECT statement is used to select data from adatabase.

q The result is stored in a result table, called the

result-set

SQL SELECT Syntax

SELECT column_name(s)FROM table_name

and

SELECT * FROM table_name

Note: SQL is not case sensitive. SELECT is the sameas select.


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An SQL SELECTExample


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SELECT * Exampl

q Now we want to select all the columns from the

"Persons" table.q We use the following SELECT statement:

SELECT * FROM Persons

Tip: The asterisk (*) is a quick way of selecting allcolumns!

q The result-set will look like this:


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Navigation in aResult-set

q Most database software systems allow navigation inthe result-set with programming functions, like:Move-To-First-Record, Get-Record-Content, Move-To-Next-Record, etc.

q Programming functions like these are not a part ofthis tutorial. To learn about accessing data withfunction calls, please visit ourADO tutorial or ourPHP tutorial.
http://w3schools.com/ado/default.asphttp://w3schools.com/php/default.asphttp://w3schools.com/php/default.asphttp://w3schools.com/ado/default.asp


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The INSERT INTO Stateme

q The INSERT INTO statement is used toinsert a new row in a table.

q The INSERT INTO statement is used toinsert new records in a table.


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SQL INSERT INTO Synt

q It is possible to write the INSERT INTO statementin two forms.

q The first form doesn't specify the column names

where the data will be inserted, only their values:q INSERT INTO table_name

VALUES (value1, value2, value3,...)q The second form specifies both the column names

and the values to be inserted:q INSERT INTO table_name (column1, column2,

column3,...)VALUES (value1, value2, value3,...)


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SQL INSERT INTO Examp

We have the following "Persons" table:

q Now we want to insert a new row in the"Persons" table.


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q We use the following SQL statement:

INSERT INTO PersonsVALUES (4,'Nilsen', 'Johan', 'Bakken 2','Stavanger')

q The "Persons" table will now look like this:

SQL INSERT INTO Examp


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Insert Data Only in Specified Colu

q It is also possible to only add data in specific

columns.q The following SQL statement will add a new row,

but only add data in the "P_Id", "LastName" and

the "FirstName" columns:q INSERT INTO Persons (P_Id, LastName, FirstName)

VALUES (5, 'Tjessem', 'Jakob')

The "Persons" table will now look like this:


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The CREATE TABLE Stateme

q

The CREATE TABLE statement is used to create atable in a database.SQL CREATE TABLE SyntaxCREATE TABLE table_name(

column_name1 data_type,column_name2 data_type,column_name3 data_type,....

)q The data type specifies what type of data thecolumn can hold. For a complete reference of allthe data types available in MS Access, MySQL,and SQL Server, go to our complete

Data Types reference.

C
http://w3schools.com/sql/sql_datatypes.asphttp://w3schools.com/sql/sql_datatypes.asp


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CREATE TABLE Examp

q Now we want to create a table called "Persons"

that contains five columns: P_Id, LastName,

FirstName, Address, and City.

q We use the following CREATE TABLE statement:

q CREATE TABLE Persons

(

P_Id int,

LastName varchar(255),

FirstName varchar(255),

Address varchar(255),

City varchar(255)

CREATE TABLE E


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q The P_Id column is of type int and will hold a

number. The LastName, FirstName, Address, and

City columns are of type varchar with a maximum

length of 255 characters.

q The empty "Persons" table will now look like this:

q The empty table can be filled with data with the

INSERT INTO statement.

CREATE TABLE Examp


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Thank You !

Foreign Language Specialized

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