b09 LTHDT Java Ket Noi Co So Du Lieu

8/3/2019 b09 LTHDT Java Ket Noi Co So Du Lieu

1/23

Lp trnh hng i tngJava kt ni c s d liu

Ging vin: TS. Nguyn Mnh Hng

Hc vin Cng ngh Bu chnh Vin thng (PTIT)


2/23

2

Ni dung

Kt ni vi DB bng JDBC Chun b cu lnh QSL Ly kt qu ra x l Lm vic vi transaction Bi tp


3/23

Kt ni DB bng JDBC


4/23

4

Kt ni bng JDBC (1)

public Connection getConnection(String dbClass, String dbUrl)throws SQLException {

Connection conn = null;

try {Class.forName(dbClass);

Connection conn = DriverManager.getConnection (dbUrl);}catch(ClassNotFoundException e) {

e.printStackTrace();}catch(SQLException e) {

throws e;}

returnconn;}

String dbClass = "com.mysql.jdbc.Driver";String dbUrl =

"jdbc:mysql://your.database.domain/yourDBname";


5/23

5

Kt ni bng JDBC (2)public Connection getConnection(String dbClass, String dbUrl, StringuserName, Stringpassword) throws SQLException {

Connection conn = null;

try {Class.forName(dbClass);

Connection conn =DriverManager.getConnection (dbUrl, userName, password);}catch(ClassNotFoundException e) {

e.printStackTrace();}catch(SQLException e) {

throws e;}

returnconn;}

String dbClass = "com.mysql.jdbc.Driver";String dbUrl =

"jdbc:mysql://your.database.domain/yourDBname";


6/23

Chun b cu lnh SQL


7/237

Dng Statement (1)

String query = "Select * FROM users";

String query = "INSERT INTO users VALUES( aaa , bbb )";

String query = "UPDATE password FROM users WHERE id = 111VALUE( ccc )";

String query = "DELETE FROM users HERE id = 111";


8/238

Dng Statement (2)

try {Statement stmt = conn.createStatement();ResultSet rs = stmt.executeQuery(query);

}catch(ClassNotFoundException e) {e.printStackTrace();

}catch(SQLException e) {e.printStackTrace();

}


9/239

Dng PreparedStatement

PreparedStatement updateSales = null;

String updateString = "update products " + "set SALES = ? where ID = ?";

try { updateSales = conn.prepareStatement(updateString);

updateSales.setInt(1,value); updateSales.setInt(2,productId); updateSales.executeUpdate();

} catch (SQLException e ) { throw e;

}


10/2310

Bi tp

C hai bng CSDL:

Transaction: productId (int), value (int),dateOfTransaction(Date)

Sumary: productId (int), totalValue (int)

Vit cc preparedStatement cho vic tm cc giao dchc gi tr >= X

Vit cc preparedStatement cho vic tm cc sn phmc gi tr giao dch trung bnh >= X


11/2311

Dng StoreProcedure (1)

String createProcedure ="create procedure GET_MAX_OF_SALE(IN productId int,

OUT value int) " + "begin " +

"select MAX(value) into productValue " + "from products " + "where ID = productId; " + "select productValue; " + "end";

try {Statement stmt = conn.createStatement(); stmt.executeUpdate(createProcedure);

} catch (SQLException e ) { throw e;

}


12/2312

Dng StoreProcedure (2)

try {CallableStatement cs =

conn.prepareCall("{call SHOW_MAX_OF_SALE(?,?)}");ResultSet rs = cs.executeQuery();

cs.setInt(1, productId);cs.registerOutParameter(2, Types.INT);cs.executeQuery();

int maxValue = cs.getInt(2);

} catch (SQLException e ) {

throw e;}


13/2313

Bi tp

C hai bng CSDL:



Vit cc storeProcedure cho vic tm cc giao dch c gitr >= X

Vit cc storeProcedure cho vic tm cc sn phm cgi tr giao dch trung bnh >= X


14/23

Ly d liu ra


15/2315

D liu t ResultSet (1)



while (rs.next()) {System.out.println(rs.getString(1));

}}catch(SQLException e) {

e.printStackTrace();}


16/2316

D liu t ResultSet (2)



// get number of row in resultSetint rowcount = 0;if (rs.last()) {

rowcount = rs.getRow();rs.beforeFirst(); // not rs.first()

}

while (rs.next()) { // do something with data...

}}catch(SQLException e) {

e.printStackTrace();

}


17/23

17

Bi tp

C hai bng CSDL:



Vit chng trnh y cho vic tm cc giao dch cgi tr >= X

Vit chng trnh y cho vic tm cc sn phm cgi tr giao dch trung bnh >= X


18/23

Lm vic vi Transaction


19/23

19

iu khin ch commit (1)

try { conn.setAutoCommit(false);

....

conn.commit();

} catch (SQLException e ) { if (conn != null) { try { conn.rollback();

} catch(SQLException excep) { throw excep;

}}

throw e;} finally {

conn.setAutoCommit(true);}

}


20/23

20

iu khin ch commit (2)publicvoidupdateSales(int productId, int value) throwsSQLException {

PreparedStatement updateSales = null;PreparedStatement updateTotal = null;

String updateString = "update products " + "set SALES = ? where ID = ?";

String updateStatement = "update totalSale " + "set TOTAL = TOTAL + ? where productId = ?";

try {

conn.setAutoCommit(false);updateSales = conn.prepareStatement(updateString);updateTotal = conn.prepareStatement(updateStatement);

updateSales.setInt(1, value);updateSales.setInt(2, productId);updateSales.executeUpdate();


21/23

21

iu khin ch commit (3)

updateTotal.setInt(1, value);updateTotal.setInt(2, productId);updateTotal.executeUpdate();

conn.commit();} catch (SQLException e ) {

if (conn != null) {

try { conn.rollback();

} catch(SQLException excep) { throw excep;

}}

throw e;} finally { if (updateSales != null) { updateSales.close(); } if (updateTotal != null) { updateTotal.close(); } conn.setAutoCommit(true);

}}


22/23

22

Bi tp

Ci t mt ng dng CSDL Vit hm main cho phn phn ci t


23/23

Questions?

b09 LTHDT Java Ket Noi Co So Du Lieu

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