package bean;
import java.sql.*;public class method {
String sDBDriver="com.mysql.jdbc.Driver";
String sConnStr="jdbc:mysql://localhost:3306/mysql?user=root&password=root";
Connection conn = null;
ResultSet rs = null;
public method() {
try {
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e) {
System.err.println( e.getMessage());
}
}
public ResultSet executeQuery(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
Statement stmt = conn.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY
);
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println(ex.getMessage());
}
return rs;
}
public int executeUpdate(String sql) {
int result = 0;
try {
conn = DriverManager.getConnection(sConnStr);
Statement stmt = conn.createStatement();
result = stmt.executeUpdate(sql);
}
catch(SQLException ex) {
System.err.println(ex.getMessage());
}
return result;
}
public void closeConn() {
try {
if (conn != null)
conn.close();
} catch (SQLException ex) {
System.err.println( ex.getMessage());
}
}
}
哪里错了,数据库连接不上
import java.sql.*;public class method {
String sDBDriver="com.mysql.jdbc.Driver";
String sConnStr="jdbc:mysql://localhost:3306/mysql?user=root&password=root";
Connection conn = null;
ResultSet rs = null;
public method() {
try {
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e) {
System.err.println( e.getMessage());
}
}
public ResultSet executeQuery(String sql) {
try {
conn = DriverManager.getConnection(sConnStr);
Statement stmt = conn.createStatement
(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY
);
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println(ex.getMessage());
}
return rs;
}
public int executeUpdate(String sql) {
int result = 0;
try {
conn = DriverManager.getConnection(sConnStr);
Statement stmt = conn.createStatement();
result = stmt.executeUpdate(sql);
}
catch(SQLException ex) {
System.err.println(ex.getMessage());
}
return result;
}
public void closeConn() {
try {
if (conn != null)
conn.close();
} catch (SQLException ex) {
System.err.println( ex.getMessage());
}
}
}
哪里错了,数据库连接不上
这样才能用com.mysql.jdbc.Driver你的连接字符串看起来是没错的org.gjt.mm.mysql.Driver 用这个的时候,使用的是另一个JAR
mm.mysql不同团队开发出来的产品
看命名空间就知道了
右击我的电脑,属性,高级,环境变量,新建系统环境变量
class_path
.;D:\java\jdk\libs\[重要的文件].jar;[你的MYSQL驱动].jar环境变量可以设置多个,用;分隔
第一个点表示当前目录
第二个,是jdk安装目录里面的jar