Nurse level JDEC addition, deletion, modification and inspection exercise

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JDEC Add, delete, change and check exercises

Get ready

increase

Ideas

Code

package com.yang.example;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.yang.pojo.Brand;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

/** * @author  Fate friend I  * @date 2022/7/2-22:31 */
public class BrandTestAdd {
    
    public static void main(String[] args) throws Exception {
    
        testAdd();
    }
    /** *  add to  * 1.SQL：insert into tb_brand(brand_name,company_name,ordered,description,status) values(?,?,?,?,?); * 2.  Parameters ： need , except id All parameter information except  * 3.  result ：boolean */
    public static void testAdd() throws Exception {
    
        // Accept the parameters submitted by the page 
        String brandName=" Fragrant ";
        String companyName=" Fragrant ";
        int ordered=1;
        String description=" Circle the earth ";
        int status=1;

        //1.  obtain Connection
        //3. Load profile 
        Properties prop  = new Properties();
        prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
        //4. Get connection pool object 
        DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
        //5. Get database connection 
        Connection conn = dataSource.getConnection();

        //2.  Definition SQL
        @SuppressWarnings("SqlResolve")
        String sql="insert into tb_brand(brand_name,company_name,ordered,description,status) values(?,?,?,?,?);";
        //3.  obtain pStmt object 
        PreparedStatement pStmt =conn.prepareStatement(sql);
        //4. Set parameters 
        pStmt.setString(1,brandName);
        pStmt.setString(2,companyName);
        pStmt.setInt(3,ordered);
        pStmt.setString(4,description);
        pStmt.setInt(5,status);

        //5.  perform sql
        int count = pStmt.executeUpdate();
        //6. Processing results 
        if(count>0)
        {
    
            System.out.println(" Add success ！");
        }
        else {
    
            System.out.println(" Add failure ！");
        }
        //7.  Release collection 
        pStmt.close();
        conn.close();
    }
}

result

Delete

Ideas

Code

package com.yang.example;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.sun.org.apache.xpath.internal.SourceTree;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.Properties;

/** * @author  Fate friend I  * @date 2022/7/3-9:13 */
public class BrandTestDelete {
    
    public static void main(String[] args) throws Exception {
    
        testDelete();
    }
    /** *  Delete  * delete from tb_brand where id=? */
    public static void testDelete() throws Exception {
    
        // Accept the parameters submitted by the page 
        int id=6;
        //1. obtain Connection
        //3. Load profile 
        Properties prop = new Properties();
        prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
        //4. Get connection pool object 
        DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
        //5. Get database objects 
        Connection conn = dataSource.getConnection();
        //2. Definition SQL
        @SuppressWarnings("SqlResolve")
        String sql="delete from tb_brand where id=?";
        //3. obtain pStmt object 
        PreparedStatement pStmt = conn.prepareStatement(sql);
        //4. Set parameters 
        pStmt.setInt(1,id);
        //5. perform sql
        int count = pStmt.executeUpdate();
        //6. Processing results 
        if(count>0) {
    
            System.out.println(" Delete successful ！");
        }else {
    
            System.out.println(" Delete failed ！");
        }
        //7. Release collection 
        pStmt.close();
        conn.close();
    }
}

result

Change

Ideas

Code

package com.yang.example;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.Properties;

/** * @author  Fate friend I  * @date 2022/7/2-22:58 */
public class BrandTestUpdate {
    
    public static void main(String[] args) throws Exception {
    
        testUpdate();
    }

    /** *  modify  * 1. SQL update tb_brand set brand_name=?, company_name=?, ordered=?, description=?, status=? where id=? */
    public static void testUpdate() throws Exception {
    
        // Accept the parameters submitted by the page 
        String brandName=" Fragrant ";
        String companyName=" Fragrant ";
        int ordered=1000;
        String description=" Three circles around the earth ";
        int status=1;
        int id=6;

        //1.  obtain Connection
        //3. Load profile 
        Properties prop  = new Properties();
        prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
        //4. Get connection pool object 
        DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
        //5. Get database connection 
        Connection conn = dataSource.getConnection();

        //2.  Definition SQL
        @SuppressWarnings("SqlResolve")
        String sql="update tb_brand\n" +
                " set brand_name=?,\n" +
                " company_name=?,\n" +
                " ordered=?,\n" +
                " description=?,\n" +
                " status=?\n" +
                " where id=?";
        //3.  obtain pStmt object 
        PreparedStatement pStmt =conn.prepareStatement(sql);
        //4. Set parameters 
        pStmt.setString(1,brandName);
        pStmt.setString(2,companyName);
        pStmt.setInt(3,ordered);
        pStmt.setString(4,description);
        pStmt.setInt(5,status);
        pStmt.setInt(6,id);

        //5.  perform sql
        int count = pStmt.executeUpdate();
        //6. Processing results 
        if(count>0)
        {
    
            System.out.println(" Modification successful ！");
        }
        else {
    
            System.out.println(" Modification failed ！");
        }
        //7.  Release collection 
        pStmt.close();
        conn.close();
    }
}

result

check

Ideas

Code

package com.yang.example;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.yang.pojo.Brand;

import javax.sql.DataSource;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

/** * @author  Fate friend I  * @date 2022/7/2-15:24 *  Addition, deletion, modification and query of brand data  */
public class BrandTextSelect {
    
    public static void main(String[] args) {
    
        try {
    
            testSelectAll();
        } catch (Exception e) {
    
            e.printStackTrace();
        }
    }

    /** *  Query all  * 1.SQL;select * from tb_brand * 2. Parameters ： Unwanted  * 3. result ：List<Brand> */
    public static void testSelectAll() throws Exception {
    
        //1.  obtain Connection
        //3. Load profile 
        Properties prop  = new Properties();
        prop.load(new FileInputStream("jdbc-demo/src/druid.properties"));
        //4. Get connection pool object 
        DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);
        //5. Get database connection 
        Connection conn = dataSource.getConnection();

        //2.  Definition SQL
        @SuppressWarnings("SqlResolve")
        String sql="select * from tb_brand";
        //3.  obtain pStmt object 
        PreparedStatement pStmt =conn.prepareStatement(sql);
        //4. Set parameters 

        //5.  perform sql
        ResultSet rs=pStmt.executeQuery();
        //6. Processing results  List<Brand> encapsulation Brand object , load List aggregate 
        Brand brand=null;
        List<Brand> brands=new ArrayList<>();
        while(rs.next()) {
    
            // get data 
            int id=rs.getInt("id");
            String brandName = rs.getString("brand_name");
            String companyName = rs.getString("company_name");
            int ordered = rs.getInt("ordered");
            String description = rs.getString("description");
            int status = rs.getInt("status");
            // encapsulation Brand object 
            brand=new Brand();
            brand.setId(id);
            brand.setBrandName(brandName);
            brand.setCompanyName(companyName);
            brand.setOrdered(ordered);
            brand.setDescription(description);
            brand.setStatus(status);
            // Encapsulation set 
            brands.add(brand);
        }
        System.out.println(brands);
        //7.  Release collection 
        rs.close();
        pStmt.close();
        conn.close();
    }
}

result