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public void CreateTableTest(){
//获取连接
Connection cnn2=SqlDB.getconnection();
Statement statement = null;
try {
statement = cnn2.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
//准备SQL语句
String sql ="CREATE TABLE student(sid INT PRIMARY KEY,sname VARCHAR(20),age INT)";
System.out.println("CREATE TABLE student......");
//调用executeQuery执行查询语
try {
statement.executeUpdate(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SqlDB.close(statement,cnn2);
}
public void InsertTest(){
//获取连接
Connection cnn2=SqlDB.getconnection();
Statement statement=null;
try {
statement = cnn2.createStatement();
} catch (SQLException e) {
e.printStackTrace();
}
//执行插入操作
System.out.println("Inserting records into the table...");
String sql = "INSERT INTO student " +
"VALUES (100, '小文', 18)";
try {
statement.executeUpdate(sql);
} catch (SQLException e1) {
e1.printStackTrace();
}
sql = "INSERT INTO student " +
"VALUES (101, '大林', 25)";
try {
statement.executeUpdate(sql);
} catch (SQLException e1) {
e1.printStackTrace();
}
sql = "INSERT INTO student " +
"VALUES (102, '阿白', 30)";
try {
statement.executeUpdate(sql);
} catch (SQLException e1) {
e1.printStackTrace();
}
sql = "INSERT INTO student " +
"VALUES(103, '小小', 28)";
try {
statement.executeUpdate(sql);
} catch (SQLException e1) {
e1.printStackTrace();
}
System.out.println("Inserted records into the table...");
SqlDB.close(statement, cnn2);
}
public void SelectTest(){
//获取连接
Connection cnn2=SqlDB.getconnection();
Statement statement=null;
try {
statement = cnn2.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//准备SQL语句
String sql = "select * from student";
//调用executeQuery执行查询语句
ResultSet res = null;
try {
res = statement.executeQuery(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//查询结束后res会指向表头，想要获取数据必须不断地指向查询结果的下一行，当没有下一行数据时，返回0.
System.out.println("select records from the table...");
try {
while(res.next())
{
//先获取数据
int sid = res.getInt("sid");
String sname = res.getString("sname");
int age = res.getInt("age");
//打印结果
System.out.print("sid: " + sid);
System.out.print(" sname: " +sname);
System.out.println(" age: " + age);
}
} catch (SQLException e) {
e.printStackTrace();
}
try {
res.close();
} catch (SQLException e) {
e.printStackTrace();
}
SqlDB.close(statement, cnn2);
}
然后就是调用：
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JdbcTest jdbcTest=new JdbcTest(); jdbcTest.CreateTableTest(); jdbcTest.InsertTest(); jdbcTest.SelectTest();结果：
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发现代码量反而增多了。。。。看来还优化得不好
想办法看是否能把创建数据库、插入数据、查找数据都入在SqlDB之中，然后我们需要时只要传入相应的参数即可，下面就来对SqlDB来进行改造：
把创建数据库、插入和查找都放到一个文件中去
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package com.mucfc;
import java.sql.*;
/**
* 数据库操作类的一个简单封装
* @author 林炳文
* @time 2015.4.30
*/
public class SqlDB {
// 定义数据库驱动程序
private static final String DBDRIVER = "com.mysql.jdbc.Driver";
// 数据库连接地址
private