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HomeDatabaseMysql Tutorialjava简单的MySQL数据库连接增删改查_MySQL

1. 连接数据库,得到数据库连接变量

 

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  1. //注意,这是连接mysql的方法  
//注意,这是连接mysql的方法

 

注意连接数据库的时候

(1)打开DB Browser 新建一个Database Driver,注意添加Driver JARs的时候添加的包,我的是mysql-connector-java-5.0.3-bin.jar

(2)要将数据库jar包拷贝到工程下的WEB-INF\lib下

 

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  1. import java.sql.Connection;//java包  
  2. public class DBConnection  
  3.     {  
  4.         private String dbDriver="com.mysql.jdbc.Driver";   
  5.         private String dbUrl="jdbc:mysql://[ip地址]:[端口号]/[数据库名]";//根据实际情况变化  
  6.         private String dbUser="root";  
  7.         private String dbPass="root";  
  8.         public Connection getConn()  
  9.         {  
  10.             Connection conn=null;  
  11.             try  
  12.             {  
  13.                 Class.forName(dbDriver);  
  14.             }  
  15.             catch (ClassNotFoundException e)  
  16.             {  
  17.                 e.printStackTrace();  
  18.             }  
  19.             try  
  20.             {  
  21.                 conn = DriverManager.getConnection(dbUrl,dbUser,dbPass);//注意是三个参数  
  22.             }  
  23.             catch (SQLException e)  
  24.             {  
  25.                 e.printStackTrace();  
  26.             }  
  27.             return conn;  
  28.         }  
  29.     }  
import java.sql.Connection;//java包
public class DBConnection
	{
		private String dbDriver="com.mysql.jdbc.Driver"; 
		private String dbUrl="jdbc:mysql://[ip地址]:[端口号]/[数据库名]";//根据实际情况变化
		private String dbUser="root";
		private String dbPass="root";
		public Connection getConn()
		{
			Connection conn=null;
			try
			{
				Class.forName(dbDriver);
			}
			catch (ClassNotFoundException e)
			{
				e.printStackTrace();
			}
			try
			{
				conn = DriverManager.getConnection(dbUrl,dbUser,dbPass);//注意是三个参数
			}
			catch (SQLException e)
			{
				e.printStackTrace();
			}
			return conn;
		}
	}

 

2. 插入操作

 

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  1. public int insert()  
  2. {  
  3.     int i=0;  
  4.     String sql="insert into (表名)(列名1,列明2) values(?,?)";  
  5.     Connection cnn=getConn();  
  6.   
  7.     try{  
  8.         PreparedStatement preStmt =cnn.prepareStement(sql);  
  9.         preStmt.setString(1,值);  
  10.         preStmt.setString(2,值);//或者:preStmt.setInt(1,值);  
  11.         i=preStmt.executeUpdate();  
  12.     }  
  13.     catch (SQLException e)  
  14.     {  
  15.         e.printStackTrace();  
  16.     }  
  17.     return i;//返回影响的行数,1为执行成功  
  18. }  
	public int insert()
	{
		int i=0;
		String sql="insert into (表名)(列名1,列明2) values(?,?)";
		Connection cnn=getConn();

		try{
			PreparedStatement preStmt =cnn.prepareStement(sql);
			preStmt.setString(1,值);
			preStmt.setString(2,值);//或者:preStmt.setInt(1,值);
			i=preStmt.executeUpdate();
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		return i;//返回影响的行数,1为执行成功
	}
3. 更新操作

 

 

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  1. public int update  
  2. {  
  3.     int i=0;  
  4.     String sql="update (表名) set  (列名1)=?,列明2=? where (列名)=?";//注意要有where条件  
  5.     Connection cnn=getConn();  
  6.   
  7.   
  8.     try{  
  9.         PreparedStatement preStmt =cnn.prepareStatement(sql);  
  10.         preStmt.setString(1,(值));  
  11.         preStmt.setString(2,(值));//或者:preStmt.setInt(1,值);  
  12.         preStmt.setInt(3,(值));  
  13.         i=preStmt.executeUpdate();  
  14.     }  
  15.     catch (SQLException e)  
  16.     {  
  17.         e.printStackTrace();  
  18.     }  
  19.     return i;//返回影响的行数,1为执行成功  
  20. }  
	public int update
	{
		int i=0;
		String sql="update (表名) set  (列名1)=?,列明2=? where (列名)=?";//注意要有where条件
		Connection cnn=getConn();


		try{
			PreparedStatement preStmt =cnn.prepareStatement(sql);
			preStmt.setString(1,(值));
			preStmt.setString(2,(值));//或者:preStmt.setInt(1,值);
			preStmt.setInt(3,(值));
			i=preStmt.executeUpdate();
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		return i;//返回影响的行数,1为执行成功
	}


 


4. 查找操作

 

 

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  1. public String select  
  2.     {  
  3.         String sql = "select * from (表名) where (列名)=(值)";  
  4.         Connection cnn = getConn();//此处为通过自己写的方法getConn()获得连接  
  5.         try  
  6.         {  
  7.             Statement stmt = conn.createStatement();  
  8.             ResultSet rs = stmt.executeQuery(sql);  
  9.   
  10.             if(rs.next())  
  11.             {  
  12.                 int m1 = rs.getInt(1);//或者为rs.getString(1),根据数据库中列的值类型确定,参数为第一列  
  13.                 String m2 = rs.getString(2);  
  14.             }  
  15.             //可以将查找到的值写入类,然后返回相应的对象  
  16.         }  
  17.         catch (SQLException e)  
  18.         {  
  19.             e.printStackTrace();  
  20.         }  
  21.         return (相应的值的变量);  
  22.     }  
public String select
	{
		String sql = "select * from (表名) where (列名)=(值)";
		Connection cnn = getConn();//此处为通过自己写的方法getConn()获得连接
		try
		{
			Statement stmt = conn.createStatement();
			ResultSet rs = stmt.executeQuery(sql);

			if(rs.next())
			{
				int m1 = rs.getInt(1);//或者为rs.getString(1),根据数据库中列的值类型确定,参数为第一列
				String m2 = rs.getString(2);
			}
			//可以将查找到的值写入类,然后返回相应的对象
		}
		catch (SQLException e)
		{
			e.printStackTrace();
		}
		return (相应的值的变量);
	}

5. 删除操作

 

 

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  1. public int delete()  
  2. {  
  3.     String sql = "delete from (表名) where (列名)=(值)";  
  4.     int i=0;  
  5.     Connection conn = getConn();//此处为通过自己写的方法getConn()获得连接  
  6.     try  
  7.     {  
  8.         Statement stmt = conn.createStatement();  
  9.         i = stmt.executeUpdate(sql);  
  10.     }  
  11.     catch (SQLException e)  
  12.     {  
  13.         e.printStackTrace();  
  14.     }  
  15.     return i;//如果返回的是1,则执行成功;  
  16. }  
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