sql basic 1

8/9/2019 SQL Basic 1

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Experiment No. – 9, 10

Aim: To Study SQL Basics.

Teory:

SQL is a standard language for accessing and manipulating databases.

• SQL stands for Structured Query Language

• SQL lets you access and manipulate databases

• SQL is an ANSI (American National Standards Institute) standard

What Can SQL do?

• 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 ne databases

• SQL can create ne tables in a database

• SQL can create stored procedures in a database

• SQL can create vies in a database

• SQL can set permissions on tables! procedures! and vies

RDBMS

"#$%S stands for "elational #atabase %anagement System.

"#$%S is t&e basis for SQL! and for all modern database systems suc& as %S SQL Server! I$% #$'!

racle! %ySQL! and %icrosoft Access.&e data in "#$%S is stored in database ob*ects called tables.

A table is a collection of related data entries and it consists of columns and ros.

SQL DML and DDL

SQL can be divided into to parts+ &e #ata %anipulation Language (#%L) and t&e #ata #efinition

Language (##L).

&e query and update commands form t&e #%L part of SQL+

• SELE!T , extracts data from a database

• "#$ATE , updates data in a database

• $ELETE , deletes data from a database

• %NSE&T %NT' , inserts ne data into a database


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&e ##L part of SQL permits database tables to be created or deleted. It also defines indexes (-eys)!

specifies lin-s beteen tables! and imposes constraints beteen tables. &e most important ##L

statements in SQL are+

• !&EATE $ATABASE , creates a ne database

• ALTE& $ATABASE , modifies a database

• !&EATE TABLE , creates a ne table

• ALTE& TABLE , modifies a table

•

$&'# TABLE , deletes a table• !&EATE %N$E( , creates an index (searc& -ey)

• $&'# %N$E( , deletes an index

1. The CREATE TABLE Statement

&e "/A/ A$L/ statement is used to create a table in a database.

SQL CREATE TABLE Syntax

"/A/ A$L/ table0name

(

column0name1 data0type!

column0name' data0type!

column0name2 data0type!

....

)

&e data type specifies &at type of data t&e column can &old.

SQL) !&EATE TABLE Students * +%$ int,

Name -arcar+100,

/ Branc -arcar+100,

Ae int2

Ta34e created.


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2.The SQL SELECT Statement

&e S/L/ statement is used to select data from a database.

&e result is stored in a result table! called t&e result,set.

SQL SELECT Syntax

S/L/ column0name(s)

3"% table0name

and

S/L/ 4 3"% table0name

SQL> select !"om st#dents$

no "o%s selected

&&&&&&&&&&& &&&&&&&&&& &&&&&&&&&&&&&

'.The ()SERT ()T* Statement

&e INS/" IN statement is used to insert a ne ro in a table.

SQL ()SERT ()T* Syntax

It is possible to rite t&e INS/" IN statement in to forms.

&e first form doesn5t specify t&e column names &ere t&e data ill be inserted! only t&eir values+

INS/" IN table0name

6AL7/S (value1! value'! value2!...)

&e second form specifies bot& t&e column names and t&e values to be inserted+


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INS/" IN table0name (column1! column'! column2!...)

6AL7/S (value1! value'! value2!...)

SQL) insert into students

* -a4ues+1,5sana5,5computer5,02

1 ro6 created.

SQL) insert into students+%$,Name,Branc,Ae

* -a4ues+*,5seema5,5%T5,02

1 ro6 created.

SQL) se4ect 7 8rom Students2

%$ NAE B&AN! A;E


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SQL) se4ect distinct Branc 8rom students2

B&AN!


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* 6ere id?1 or Ae?*>2

NAE


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Note: Notice t&e 89/"/ clause in t&e 7

SQL) update students

* set 3ranc?5ec5

6ere name?5=on52

1 ro6 updated.

SQL) se4ect 7 8rom students2

%$ NAE B&AN! A;E


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sql basic 1

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