scala 连接 MySQL 数据库案例

1 依赖准备

mysql 8添加：

    <dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.29</version></dependency>

mysql 5 添加：

    <dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.36</version></dependency>

当然为了避免下载，可以直接去你的本地仓库查看你以前下过什么版本的依赖

2 连接 mysql 数据库并进行数据操作

        这里的driver 换成对应自己版本的驱动

        mysql 8 就是 com.mysql.cj.jdbc.Driver

        mysql 5 就是 com.mysql.jdbc.Driver

        这里的 url 一样换成自己的，若是在服务器上就换成服务器 ip，若在本地就用 localhost 就可以

        这里只要能打印出连接，能添加进数据就算成功，其余的无非是 Java 连接数据库的操作了，大差不差了 ，有兴趣的可以自己往下加需求

        这里的的数据库结构是

        建表语句：

show databases ;create database kb23test;
use kb23test;
create table student(id int,name varchar(32),age int
);select * from student;

package mysqlstuimport java.sql.{Connection, DriverManager, PreparedStatement, ResultSet}class MysqlDemo {
//  var driver : String = "com.mysql.jdbc.Driver"var driver : String = "com.mysql.cj.jdbc.Driver"
//  var url = "jdbc:mysql://127.0.0.1:3306"var url = "jdbc:mysql://39.107.230.113:3306"var user = "root"var pwd = "100860"var connection : Connection = nulldef this(driver : String,url : String,user : String,pwd : String){this()this.driver = driverthis.url = urlthis.user = userthis.pwd = pwd}def conn : Connection={Class.forName(driver)connection = DriverManager.getConnection(url,user,pwd)connection}def insert():Int = {val insertSql = "insert into kb23test.student(id,name,age) values(1,'jojo',12)"if (connection == null) connval i : Int = connection.createStatement().executeUpdate(insertSql)i}def insert(id:Int,name:String,age:Int):Int = {val insertSql = "insert into kb23test.student(id,name,age) values(?,?,?)"if (connection == null) connval pstm : PreparedStatement = connection.prepareStatement(insertSql)pstm.setInt(1,id)pstm.setString(2,name)pstm.setInt(3,age)val i : Int = pstm.executeUpdate()i}def update(id:Int,name:String,age:Int):Int = {val insertSql = "update kb23test.student set name = ?,age = ? where id = ?"if (connection == null) connval pstm : PreparedStatement = connection.prepareStatement(insertSql)pstm.setInt(3,id)pstm.setString(1,name)pstm.setInt(2,age)val i : Int = pstm.executeUpdate()i}def select():Unit={val selectSql = "select id,name,age from kb23test.student"if (connection == null)connval rs : ResultSet = connection.createStatement().executeQuery(selectSql)while(rs.next()){val id : Int = rs.getInt("id")val name : String = rs.getString("name")val age : Int = rs.getInt("age")println("学号：%d 姓名：%s 年龄：%d".format(id,name,age))}}def select(name:String):Unit={val selectSql = "select id,name,age from kb23test.student where name like concat('%',?,'%')"if (connection == null)connval pstm = connection.prepareStatement(selectSql)pstm.setString(1,name)val rs : ResultSet = pstm.executeQuery()while(rs.next()){val id : Int = rs.getInt("id")val name : String = rs.getString("name")val age : Int = rs.getInt("age")println("学号：%d 姓名：%s 年龄：%d".format(id,name,age))}}
}object MysqlDemo{def main(args: Array[String]): Unit = {val mysqlDemo = new MysqlDemoprintln(mysqlDemo.conn)//    println(mysqlDemo.insert())
//    println(mysqlDemo.insert(2,"dio",142))
//    println(mysqlDemo.update(2,"dio",112))
//    mysqlDemo.select("d")mysqlDemo.select()}
}

3 隐式类形式去实现连接 mysql

package mysqlstuimport java.sql.Connectionclass MysqlDemo2 {//  var driver : String = "com.mysql.jdbc.Driver"var driver: String = "com.mysql.cj.jdbc.Driver"//  var url = "jdbc:mysql://127.0.0.1:3306"var url = "jdbc:mysql://39.107.230.113:3306"var user = "root"var pwd = "100860"def this(driver: String, url: String, user: String, pwd: String) {this()this.driver = driverthis.url = urlthis.user = userthis.pwd = pwd}}object MysqlDemo2 {def main(args: Array[String]): Unit = {val demo = new MysqlDemo2()import mysqlstu.MysqlUtils._demo.insert(3,"kk",11)}
}

package mysqlstuimport java.sql.{Connection, DriverManager, PreparedStatement}object MysqlUtils {implicit class Mysqlop(mysqlDemo2: MysqlDemo2){private var connection:Connection = _private def conn():Unit={Class.forName(mysqlDemo2.driver)connection = DriverManager.getConnection(mysqlDemo2.url,mysqlDemo2.user,mysqlDemo2.pwd)}def insert(id:Int,name:String,age:Int):Int = {val insertSql = "insert into kb23test.student(id,name,age) values(?,?,?)"if (connection == null) connval pstm : PreparedStatement = connection.prepareStatement(insertSql)pstm.setInt(1,id)pstm.setString(2,name)pstm.setInt(3,age)val i : Int = pstm.executeUpdate()i}}
}