JDBC连接MySQL
JDBC连接MySQL
加载及注册JDBC驱动程序
Class.forName("com.mysql.jdbc.Driver");
Class.forName("com.mysql.jdbc.Driver").newInstance();
JDBC URL 定义驱动程序与数据源之间的连接
标准语法:
<protocol(主要通讯协议)>:<subprotocol(次要通讯协议,即驱动程序名称)>:<data source identifier(数据源)>
MySQL的JDBC URL格式:
jdbc:mysql//[hostname][:port]/[dbname][?param1=value1][¶m2=value2]….
示例:jdbc:mysql://localhost:3306/sample_db?user=root&password=your_password
常见参数:
user 用户名
password 密码
autoReconnect 联机失败,是否重新联机(true/false)
maxReconnect 尝试重新联机次数
initialTimeout 尝试重新联机间隔
maxRows 传回最大行数
useUnicode 是否使用Unicode字体编码(true/false)
characterEncoding 何种编码(GB2312/UTF-8/…)
relaxAutocommit 是否自动提交(true/false)
capitalizeTypeNames 数据定义的名称以大写表示
建立连接对象
String url="jdbc:mysql://localhost:3306/sample_db?user=root&password=your_password";
Connection con = DriverManager.getConnection(url);
建立SQL陈述式对象(Statement Object)
Statement stmt = con.createStatement();
执行SQL语句
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executeQuery() String query = "select * from test" ; ResultSet rs=stmt.executeQuery(query); 结果集ResultSet while (rs.next()) {rs.getString(1);rs.getInt(2);} executeUpdate() String upd= "insert into test (id,name) values(1001,xuzhaori)" ; int con=stmt.executeUpdate(upd); execute() |
示例:
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try { } catch (SQLException sqle) { } finally { } |
Java类型和SQL类型 技术手册P421
PreparedStatement(预编语句)
PreparedStatement stmt = conn.prepareStatement("insert into test(id,name)values(?,?)");
stmt.setInt(1,id);
stmt.setString(2,name);
注:一旦设定语句的参数值后,就可以多次执行改语句,直到调用clearParameters()方法将他清除为止
CallableStatement(预储程序)技术手册P430
JDBC2.0使用
ResultSet对象中的光标上下自由移动
Statement stmt = con.createStatement (ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
ResultSet rs=stmt.executeQuery("select * from test");
public Statement createStatement(int resultSetType,int resultSetConcuttency) throws SQLException
resultSetType
TYPE_FORWARD_ONLY 只能使用next()方法。
TYPE_SCROLL_SENSITIVE 可以上下移动,可以取得改变后的值。
TYPE_SCROLL_INSENSITIVE 可以上下移动。
resultSetConcuttency
CONCUR_READ_ONLY 只读
CONCUR_UPDATABLE ResultSet对象可以执行数据库的新增、修改、和移除
直接使用ResultSet对象执行更新数据
新增数据
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Statement stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_PUDATABLE); ResultSet uprs=stmt.executeQuery( "select * from test" ); uprs.moveToInsertRow(); uprs.updateInt(1,1001); uprs.updateString(2, "许召日" ); uprs.insertRow; |
更新数据
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Statement stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_PUDATABLE); ResultSet uprs=stmt.executeQuery( "select * from test" ); uprs.last(); uprs.updateString( "name" , "xuzhaori" ); uprs.updateRow; |
删除数据
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Statement stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_PUDATABLE); ResultSet uprs=stmt.executeQuery( "select * from test" ); uprs.absolute(4); uprs.deleteRow(); |
批处理
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con.setAutoCommit( false ); 关闭自动认可模式 Statement stmt=con.createStatement(); int [] rows ; stmt.addBatch( "insert into test values(1001,xuzhaori)" ); stmt.addBatch( "insert into test values(1002,xuyalin)" ); rows =stmt.executeBatch(); con. commit (); 没有任何错误,执行批处理stmt.executeBatch(); |
JNDI-数据源(Data Source)与连接池(Connection Pool)
Tomcat的JDBC数据源设置 技术手册P439
连接池工具-Proxool Var 0.8.3 技术手册P446
设置web.xml
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<? xml version = "1.0" encoding = "ISO-8859-1" ?> <!--<?xml version="1.0" encoding="GB2312"?>--> < web-app xmlns = "http://java.sun.com/xml/ns/j2ee" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version = "2.4" > …. < servlet > < servlet-name >ServletConfigurator</ servlet-name > < servlet-class >org.logicalcobwebs.proxool.configuration.ServletConfigurator</ servlet-class > < init-param > < param-name >propertyFile</ param-name > < param-value >WEB-INF/classes/Proxool.properties</ param-value > </ init-param > < load-on-startup >1</ load-on-startup > </ servlet > 后端统计端口添加下列 < servlet > < servlet-name >Admin</ servlet-name > < servlet-class >org.logicalcobwebs.proxool.admin.servlet.AdminServlet</ servlet-class > </ servlet > < servlet-mapping > < servlet-name >Admin</ servlet-name > < url-pattern >/Admin</ url-pattern > </ servlet-mapping > …. </ web-app > |
配置Proxool.properties
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jdbc-0.proxool.alias=JSPBook jdbc-0.proxool.driver-class=com.mysql.jdbc.Driver jdbc-0.proxool.driver-url=jdbc:mysql://localhost:3306/sample_db? user =root& password =browser&useUnicode= true &characterEncoding=UTF-8 jdbc-0.proxool.maximum- connection - count =10 jdbc-0.proxool.prototype- count =4 jdbc-0.proxool.house-keeping-test-sql= select CURRENT_DATE jdbc-0.proxool.verbose= true jdbc-0.proxool. statistics =10s,1m,1d 后端统计接口添加此行 jdbc-0.proxool. statistics -log- level =DEBUG |
使用Proxool连接池
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Connection con = DriverManager.getConnection( "proxool.JSPBook" ); Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE); String query = "SELECT * FROM employee" ; ResultSet rs = stmt.executeQuery(query); |
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原文链接:http://www.cnblogs.com/cy163/archive/2008/08/22/1274413.html