UNIT- IVCHAPTER IN BOOK- 4

JDBCPART- I

-K. Indhu

SYLLABUS COVERED HERE• Database Systems• Introduction• Structured Query Language

GOALS1. Database Systems2. Introduction3. Structured Query Language4. SQL Data Types5. Creating Table in SQL6. Simple Database Application7. Client – Server Application8. Three Tier Application9. Typical Uses of JDBC

DATABASE SYSTEMS• System containing repository of “DATA” (or)

“INFORMATION” is called as Database Systems.

• Most popular form of database system is the “Relational Database System”.

• Structured Query Language (SQL) is used among relational databases to construct queries.

• Using SQL, Java Applications need to query Back-end Databases.

DATABASE SYSTEMS• Relational database– Table=> A Data Structure comprising of Rows, Columns– Record=> Horizontal Set of Row of data in the Table– Field=> Vertical Set of Column Data in the Table– Primary key=> Unique Column that identifies a Row.• Unique data

• SQL statement– Query=> Similar to English Programming Statement,– => Used to fetch data from table (or) tables.

STRUCTURED QUERYLANGUAGE

• SQL KEYWORDS :-

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY :-• Simplest format of a SELECT query– SELECT * FROM tableName– SELECT * FROM authors

• Select specific fields from a table– SELECT authorID, lastName FROM authors

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY USING “WHERE” CLAUSE :-• specify the selection criteria– SELECT fieldName1, fieldName2, … FROM tableName WHERE criteria

– SELECT title, editionNumber, copyrightFROM titles

WHERE copyright > 1999

• WHERE clause condition operators– <, >, <=, >=, =, <>– LIKE

• wildcard characters % and _

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY USING “WHERE” CLAUSE :-• SELECT authorID, firstName, lastName

FROM authorsWHERE lastName LIKE ‘D%’

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY USING “WHERE” CLAUSE :-• SELECT authorID, firstName, lastName

FROM authorsWHERE lastName LIKE ‘_i%’

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- “ORDER BY” CLAUSE :-• Optional ORDER BY clause– SELECT fieldName1, fieldName2, … FROM tableName ORDER BY field ASC

– SELECT fieldName1, fieldName2, … FROM tableName ORDER BY field DESC

• ORDER BY multiple fields– ORDER BY field1 sortingOrder, field2 sortingOrder, …

• Combine the WHERE and ORDER BY clauses

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- “ORDER BY” CLAUSE :-• SELECT authorID, firstName, lastName

FROM authorsORDER BY lastName ASC

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- “ORDER BY” CLAUSE :-• SELECT authorID, firstName, lastName

FROM authorsORDER BY lastName DESC

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- MIXTURE OF ALL CLAUSES :-• SELECT isbn, title, editionNumber, copyright, price

FROM titles WHERE title LIKE ‘%How to Program’ORDER BY title ASC

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- INSERT DATA INTO TABLE :-• Insert a new record into a table

• INSERT INTO tableName ( fieldName1, … , fieldNameN ) VALUES ( value1, … , valueN )

• INSERT INTO authors ( firstName, lastName ) VALUES ( ‘Sue’, ‘Smith’ )

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- UPDATE DATA IN TABLE :-• Modify data in a table• UPDATE tableName SET fieldName1 = value1, … , fieldNameN = valueN

WHERE criteria• UPDATE authors SET lastName = ‘Jones’ WHERE lastName = ‘Smith’ AND firstName = ‘Sue’

STRUCTURED QUERYLANGUAGE

• BASIC SQL QUERY- DELETE DATA FROM TABLE :-• Remove data from a table• DELETE FROM tableName WHERE criteria • DELETE FROM authors WHERE lastName = ‘Jones’ AND firstName = ‘Sue’

SQL DATA TYPES

CREATING TABLE IN SQL• CREATE TABLE Books• (• Title CHAR(60),• ISBN CHAR(13),• Publisher_Id CHAR(5),• URL CHAR(80),• Price DECIMAL(6,2)• );

SIMPLE DATABASE APPLN.APPLICATION

DBMS DB

CLIENT-SERVER APPLICATION

THREE TIER APPLICATION

TYPICAL USES OF JDBC• (1) Use JDBC in both applications and applets.

• (2) Provides an interface to Relational Data Sources / Databases.

• (3) Provides the means for executing SQL statements to access and operate on a relational database.

K. INDHU

SO FAR WE STUDIED…• Database Systems• Introduction• Structured Query Language

HAPPY LEARNING!!!