Java如何连接SQLServer，并实现查询、修改、删除方法

场景：Ａ:在UI自动化时，删除数据时候，在界面UI提示“该XX已被使用，无法删除”。 这时候我们有需要做数据初始化的操作，需要把历史数据做删除，来确脚本运行的重复执行，和稳定性质。

B: 在做新增操作时候，需要校验数据是否存在后台。需要校验后台数据。

实现思路：

1.把数据库的连接地址、用户名、密码。 配置在框架配置文件处。

public class Const {
    public static final String DB_URL = "XXXX";
    public static final String DB_DatabaseName = "XXX";
    public static final String DB_UserName = "XXX";
    public static final String DB_Password = "XXX";
}

2.DBHelper 方法

 package com.pensee.utils;

 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import com.pensee.config.Const;

 public class DBHelper {
     static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
     static String url = "jdbc:sqlserver://"+ Const.DB_URL +";DatabaseName="+ Const.DB_DatabaseName +"";
     static Connection con = null;
     static Statement st = null;
     static ResultSet res = null;

     public static void dataBase() {
         try {
             Class.forName(driver);
             con = DriverManager.getConnection(url, ""+ Const.DB_UserName +"", ""+ Const.DB_Password +"");
         } catch (ClassNotFoundException e) {
             System.err.println("装载 JDBC/ODBC 驱动程序失败。");
             e.printStackTrace();
         } catch (SQLException e) {
             System.err.println("无法连接数据库");
             e.printStackTrace();
         }
     }

     /**
      * 查询SQL方法
      * @param sql
      * @return
      * @throws SQLException
      */
     public static ResultSet find(String sql) throws SQLException{//对数据库进行数据查询
         //获得连接
         dataBase();
         st=con.createStatement();
         try {
             res=st.executeQuery(sql);
             return res;
         } catch (SQLException e) {
             e.printStackTrace();
             return null;
         }

     }
     /**
      * SQL删除修改
      * @param sql
      * @return
      * @throws SQLException
      */
     public static boolean update(String sql) throws SQLException{//对增删改
         //获得连接
         dataBase();
         st = con.createStatement();
         try {
             st.executeUpdate(sql);
             return true;
         } catch (SQLException e) {
             e.printStackTrace();
             return false;
         }
     }

 }

3. 如何调用DB

String sql = "update hr_staff_policy set HolidayPolicy = 3  where staffno ='0092'";
boolean result = DBHelper.update(sql);
Assert.isTrue(result);
System.out.println("SQL执行结果为：" +DBHelper.update(sql));

4. 效果图：

框架如何增加JDBC

<dependency>
    <groupId>com.microsoft.sqlserver</groupId>
    <artifactId>sqljdbc4</artifactId>
    <version>4.0</version>
</dependency>

进入sqljdbc4.jar包所在的位置，cmd运行以下命令（即在我们的project 的\lib路径下）

mvn install:install-file -Dfile=sqljdbc4.jar -Dpackaging=jar -DgroupId=com.microsoft.sqlserver -DartifactId=sqljdbc4 -Dversion=4.0

安装成功之后就可以在pom中引用sqljdbc依赖了。（已经加好上传了）

五、 优化后的代码

 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.ResultSetMetaData;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.ArrayList;

 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

 import com.pensee.config.Const;

 public class DBHelper {
     private static final Logger logger = LogManager.getLogger(DBHelper.class);

     static String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
     static String url = "jdbc:sqlserver://"+ Const.DB_URL +";DatabaseName="+ Const.DB_DatabaseName +"";

     private static Connection getDBConnection() {
         Connection con = null;
         try {
             Class.forName(driver);
             con = DriverManager.getConnection(url, ""+ Const.DB_UserName + "", ""+ Const.DB_Password +"");
         } catch (ClassNotFoundException e) {
             logger.error("装载 JDBC/ODBC 驱动程序失败。");
         } catch (SQLException e) {
             logger.error("无法连接数据库");
         }
         return con;
     }

     private static void closeConnection(Connection con) {
         try {
             con.close();
         } catch (SQLException e) {
             ;
         }
     }

     /**
      * 查询SQL方法
      * @param sql
      * @return
      * @throws SQLException
      */
     public static ArrayList<String> query(String sql) throws SQLException{//对数据库进行数据查询
         //获得连接
         Connection con = getDBConnection();
         Statement st = con.createStatement();
         ResultSet res;
         try {
             res = st.executeQuery(sql);
         } catch (SQLException e) {
             throw new RuntimeException("查询失败： " + sql);
         }
         ArrayList<String> result = new ArrayList<String>();
         while(res.next()) {
             ResultSetMetaData rsmd = res.getMetaData();
             int columnCount = rsmd.getColumnCount();
             for (int i=0;i<columnCount;i++) {
                 result.add(res.getString(i+1));
             }
         }
         closeConnection(con);
         return result;
     }
     /**
      * SQL删除修改
      * @param sql
      * @return
      * @throws SQLException
      */
     public static void updateDB(String sql) throws SQLException{//对增删改
         //获得连接
         Connection con = getDBConnection();
         Statement st = con.createStatement();
         int recordsNo = st.executeUpdate(sql);
         if(recordsNo == 0) {
             throw new RuntimeException("执行失败： " + sql);
         } else if(recordsNo == 1){
             logger.info("更新成功1条： " + sql);
         } else {
             logger.info("更新成功条数： " + recordsNo);
         }
         closeConnection(con);
     }

     //存在数据的时候更新，不存在的时候不需要更新，影响数据行数为0或者1
     public static void updateDBIfExist(String sql) throws SQLException{//对增删改
         //获得连接
         Connection con = getDBConnection();
         Statement st = con.createStatement();
         int recordsNo = st.executeUpdate(sql);
         logger.info("更新成功的record数量 " + recordsNo);
         closeConnection(con);
     }

     public static void deleteVacationBalance(String code, String staffId) throws SQLException {
         String sql = "DELETE lb FROM Leave_Balance lb LEFT JOIN Leave_Code lc ON lc.id = lb.LeaveCode_id "
                 + "WHERE lc.LeaveBenefitCode ='" + code + "' and taffno ='" + staffId + "'";
         updateDB(sql);
     } 

     /**
      * 删除历史组织架构
      * @param code
      * @param staffId
      * @throws SQLException
      */
     public static void deleteHistoryOrganzationalStructure(String hisname) throws SQLException {
         String sql = "DELETE FROM Org_DataType WHERE NAME='" + hisname + "'";
         updateDB(sql);
     } 

     /**
      * 取得员工工号，该员工没有卡，用于case E-653
      * @return
      * @throws SQLException
      */
     public static String getStaffNoWithoutCard() throws SQLException {
         String sql = "SELECT ac.staffNo FROM At_Card ac INNER JOIN hr_Staff hs ON ac.StaffNo = hs.StaffNo "
                 + "WHERE ac.No = ''  AND hs.StaffType  = 'Active'";
         String id = query(sql).get(0);
         String sqlDelete = String.format("DELETE ap  FROM At_PunchClockInfo ap INNER JOIN At_Card ac ON ap.At_Card_id = ac.Id "
                 + "WHERE ac.StaffNo ='%s'", id);
         updateDB(sqlDelete);
         return id;
     }
 }

六： jenkins配置增加JDBC