JBDCDemo

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 用于JDBC操作
 * 
 * @author
 */
public class ByteJDBC {
	private String driverName = "oracle.jdbc.driver.OracleDriver";
	private String url = "";
	private String userName = "";
	private String userPwd = "";

	/**
	 * 删除单条数据
	 * 
	 * @param tableName
	 *            表名
	 * @param idName
	 *            idName名称
	 * @param idValue
	 *            idValue值
	 */
	public void deleteById(String tableName, String idName, String idValue) {
		String sql = "delete from " + tableName + " where " + idName + "='"
				+ idValue + "'";
		doSQL(sql);
	}

	/**
	 * 执行SQL(查询) 并且返回生成结果集表格
	 * 
	 * @return String
	 */
	public String selectSQL(String selectSQL) {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		// 用来存放查询的结果
		StringBuffer sb = new StringBuffer();
		try {
			// 加载驱动
			Class.forName(driverName);
			// 创建连接
			conn = DriverManager.getConnection(url, userName, userPwd);
			// 创建Statement
			st = conn.createStatement();
			// 执行sql语句,得到查询结果
			rs = st.executeQuery(selectSQL);
			// 输出查询结果
			int cloNum = rs.getMetaData().getColumnCount();
			sb.append("<tr class=\"th\">");
			for (int i = 0; i < cloNum; i++) {
				sb.append("<td>");
				sb.append(rs.getMetaData().getColumnName(i + 1));
				sb.append("</td>");
			}
			sb.append("</tr>");
			while (rs.next()) {
				sb.append("<tr>");
				for (int i = 0; i < cloNum; i++) {
					sb.append("<td>");
					sb.append(rs.getString(i + 1));
					sb.append("</td>");
				}
				sb.append("</tr>");
			}
			// 关闭资源
			rs.close();
			st.close();
			conn.close();

		} catch (Exception ex) {
			// 输出错误信息
			ex.printStackTrace();
		} finally {
			// finally子句总是会执行(就算发生错误),这样可以保证资源的绝对关闭
			try {
				if (rs != null)
					rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			try {
				if (st != null)
					st.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			try {
				if (conn != null)
					conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}

		}
		return sb.toString();
	}

	/**
	 * 执行sql语句(修改、删除,插入)
	 */
	public void doSQL(String sqlStr) {
		Connection conn = null;
		Statement st = null;
		try {
			// 加载驱动
			Class.forName(driverName);
			// 创建连接
			conn = DriverManager.getConnection(url, userName, userPwd);
			// 创建Statement
			st = conn.createStatement();
			// 执行sql语句,得到查询结果
			st.execute(sqlStr);
			// 关闭资源
			st.close();
			conn.close();
		} catch (Exception ex) {
			// 输出错误信息
			ex.printStackTrace();
		} finally {
			// finally子句总是会执行(就算发生错误),这样可以保证资源的绝对关闭
			try {
				if (st != null)
					st.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
			try {
				if (conn != null)
					conn.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}

 

``` package jdbc; import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; /** * 执行UPDATE语句 */ public class JBDCDemo3 { public static void main(String[] args) { try { Class.forName("com.mysql.cj.jdbc.Driver"); //2.注册驱动 Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/tedu?characterEncoding=utf8&use" + "SSL=false&serverTimezone=Asia/Shanghai&rewriteBatched" + "Statements=true", "root", "123456"); //3 Statement statement = connection.createStatement(); String sql="UPDATE user"+ "SET username='三嫂',password='666666',nickname='老三',age=50 "+ "WHERE id=1"; int num= statement.executeUpdate(sql); if (num>0){ System.out.println("更新成功"); }else { System.out.println("更新失败"); } connection.close(); }catch (Exception e){ e.printStackTrace(); } } }```"C:\Program Files\Java\jdk-17\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2024.3.4\lib\idea_rt.jar=61398" -Dfile.encoding=UTF-8 -classpath D:\java-student\JSD2502_SSM\JDBC\target\classes;C:\Users\2003q\.m2\repository\mysql\mysql-connector-java\8.0.15\mysql-connector-java-8.0.15.jar;C:\Users\2003q\.m2\repository\com\google\protobuf\protobuf-java\3.6.1\protobuf-java-3.6.1.jar jdbc.JBDCDemo3 java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '='三嫂',password='666666',nickname='老三',age=50 WHERE id=1' at line 1 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) at com.mysql.cj.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1355) at com.mysql.cj.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2128) at com.mysql.cj.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1264) at jdbc.JBDCDemo3.main(JBDCDemo3.java:25) 进程已结束,退出代码为 0
03-26
``` package jdbc; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * 执行dql 语句 */ public class JBDCDemo5 { public static void main(String[] args) throws SQLException { Connection connection = DBUtil.getConnection(); try { Statement statement = connection.createStatement();{ } String sql = "SELECT id,name,salary,title " + "FROM user " ; ResultSet rs =statement.executeQuery(sql); while(rs.next()){ int id=rs.getInt("id"); String name=rs.getString("name"); double salary=rs.getDouble("salary"); String title=rs.getString("title"); System.out.println(id+","+name+","+salary+","+title); } }catch (SQLException e){ e.printStackTrace(); } } }```"C:\Program Files\Java\jdk-17\bin\java.exe" "-javaagent:D:\IntelliJ IDEA 2024.3.4\lib\idea_rt.jar=62944" -Dfile.encoding=UTF-8 -classpath D:\java-student\JSD2502_SSM\JDBC\target\classes;C:\Users\2003q\.m2\repository\mysql\mysql-connector-java\8.0.15\mysql-connector-java-8.0.15.jar;C:\Users\2003q\.m2\repository\com\google\protobuf\protobuf-java\3.6.1\protobuf-java-3.6.1.jar jdbc.JBDCDemo5 java.sql.SQLSyntaxErrorException: Unknown column 'name' in 'field list' at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) at com.mysql.cj.jdbc.StatementImpl.executeQuery(StatementImpl.java:1218) at jdbc.JBDCDemo5.main(JBDCDemo5.java:21)
03-26
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值