JDBC操作数据库汇总
JDBC（Java Database Connectivity）
一、SQL语言回顾
1、Select select * from T where …
2、Insert insert into T values(…)
3、Create create table T(…)
4、Delete delete from T where…
5、Update update T set t1=… and t2=.. where t3=…
6、Drop drop table T
二、JDBC编程步骤
1、Load the Driver
Class.forName( )|Class.forName( ).newInstance( )|new DriverName( )
实例化时自动向DriverManager注册，不需显式调用DriverManager.registerDriver方法
2、Connect to the DataBase
DriverManager.getConnection( )
3、Execute the SQL
Connection.CreateStatement( )
Statement.executeQuery( )
Statement.executeUpdate( )
4、Retrieve the result data
循环取得结果while(rs.next( ))
5、Show the result data
将数据库中的各种类型转换为Java中的类型(getXXX)方法
6、Close
Close the resultset ./ close the statement / close the connection
三、JDBC操作oracle数据库
1、 JDBC连接oracle数据库：
import java.sql.*;
public class TestJDBC {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
Class.forName("oracle.jdbc.driver.OracleDriver");
//new oracle.jdbc.driver.OracleDriver();
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
}
}
2、 向数据库中取字段，遍历数据库，并显示出相应字段：
import java.sql.*;
public class TestJDBC {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
Class.forName("oracle.jdbc.driver.OracleDriver");
//new oracle.jdbc.driver.OracleDriver();
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from dept");
while(rs.next()) {
System.out.println(rs.getString("deptno"));
System.out.println(rs.getInt("deptno"));
}
rs.close();
stmt.close();
conn.close();
}
}
3、 捕捉相关异常，完善JDBC编程：
import java.sql.*;
public class TestJDBC {
public static void main(String[] args) throws ClassNotFoundException, SQLException {
ResultSet rs = null;
Statement stmt = null;
Connection conn = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
stmt = conn.createStatement();
rs = stmt.executeQuery("select * from dept");
while(rs.next()) {
System.out.println(rs.getString("deptno"));
System.out.println(rs.getInt("deptno"));
}
} catch(ClassNotFoundException e) {
e.printStackTrace();
} catch(SQLException e) {
e.printStackTrace();
} finally {
try {
if(rs != null) {
rs.close();
rs = null;
}
if(stmt != null) {
stmt.close();
stmt = null;
}
if(conn != null) {
conn.close();
conn = null;
}
} catch(SQLException e) {
e.printStackTrace();
}
}
}
}
四、JDBC编程高级
1、 JDBC处理DML语句：
import java.sql.*;
public class TestDML {
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection(
"jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
stmt = conn.createStatement();
String sql = "insert into dept2 values (99,'develop','changsha')";
stmt.executeUpdate(sql);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (stmt != null) {
stmt.close();
stmt = null;
}
if (conn != null) {
conn.close();
conn = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
2、 JDBC处理DML语句2：
import java.sql.*;
public class TestDML2 {
public static void main(String[] args) {
if (args.length != 3) {
System.out.println("Arguments error,please enter again!");
System.exit(-1);
}
int deptno = 0;
try {
deptno = Integer.parseInt(args[0]);
} catch (NumberFormatException e) {
System.out.println("Arguments error");
System.exit(-1);
}
String dname = args[1];
String loc = args[2];
Connection conn = null;
Statement stmt = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
stmt = conn.createStatement();
String sql = "insert into dept2 values (" + deptno + ",'" + dname + "','" + loc + "' )";
System.out.println(sql);
stmt.executeUpdate(sql);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (conn != null) {
conn.close();
conn = null;
}
if (stmt != null) {
stmt.close();
stmt = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
3、 JDBC处理PreparedStatement，可以灵活指定SQL语句中的变量
import java.sql.*;
public class TestPrepStmt {
public static void main(String[] args) {
if (args.length != 3) {
System.out.println("Arguments error,please enter again!");
System.exit(-1);
}
int deptno = 0;
try {
deptno = Integer.parseInt(args[0]);
} catch (NumberFormatException e) {
System.out.println("Arguments error");
System.exit(-1);
}
String dname = args[1];
String loc = args[2];
Connection conn = null;
PreparedStatement pstmt = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:solid", "scott", "tiger");
pstmt = conn.prepareStatement("insert into dept2 values (?, ?, ?)");
pstmt.setInt(1, deptno);
pstmt.setString(2, dname);
pstmt.setString(3, loc);
pstmt.executeUpdate();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (conn != null) {
conn.close();
conn = null;
}
if (pstmt != null) {
pstmt.close();
pstmt = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
4、 JDBC处理储存过程
import java.sql.*;
public class TestProc {
public static void main(String[] args) throws Exception {
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@192.168.0.1:1521:SXT", "scott", "tiger");
CallableStatement cstmt = conn.prepareCall("{call p(?, ?, ?, ?)}");
cstmt.registerOutParameter(3, Types.INTEGER);
cstmt.registerOutParameter(4, Types.INTEGER);
cstmt.setInt(1, 3);
cstmt.setInt(2, 4);
cstmt.setInt(4, 5);
cstmt.execute();
System.out.println(cstmt.getInt(3));
System.out.println(cstmt.getInt(4));
cstmt.close();
conn.close();
}
}
5、 JDBC进行批处理
import java.sql.*;
public class TestBatch {
public static void main(String[] args) throws Exception {
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@192.168.0.1:1521:SXT", "scott", "tiger");
/*
Statement stmt = conn.createStatement();
stmt.addBatch("insert into dept2 values (51, '500', 'haha')");
stmt.addBatch("insert into dept2 values (52, '500', 'haha')");
stmt.addBatch("insert into dept2 values (53, '500', 'haha')");
stmt.executeBatch();
stmt.close();
*/
PreparedStatement ps = conn.prepareStatement("insert into dept2 values (?, ?, ?)");
ps.setInt(1, 61);
ps.setString(2, "haha");
ps.setString(3, "bj");<