这篇文章主要讲解了“Java Scala怎么实现数据库增删查改操作”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“Java Scala怎么实现数据库增删查改操作”吧！
添加jar包
这里的Scala不是maven工程所以要找到项目结构（快捷键：同时按住Ctrl+shift+Alt+s）在模块里面添加添加MySQL的jar包，如果是Maven工程可以直接在pom里面直接加即可
实现操作数据库需要两个类，一个用于测试的Demo，一个用于实现增删查改的Util方法
在MysqlDemo在这里需要用到伴生类和伴生对象，伴生类主要是实现连接数据库
class MysqlDemo { // 连接数据库 底层原理还是jdbc //驱动名称 var driver = "com.mysql.cj.jdbc.Driver" // 访问MySQL服务器，通过3306端口访问mysql数据库 var url = "jdbc:mysql://192.168.152.184:3306/exam" //用户名 var user = "root" //密码 var password = "123456" //辅助构造器 def this(driver: String, url: String, user: String, pwd: String) { this() this.driver = driver this.url = url this.user = user this.password = pwd }}伴生对象则主要是实现操作数据库 ，需要先实现apply方法，主函数里面创建对象调用apply方法，调用连接方法和释放资源
object MysqlDemo { // 实现apply方法 def apply(): MysqlDemo = new MysqlDemo() def apply(driver: String, url: String, user: String, pwd: String): MysqlDemo = new MysqlDemo(driver, url, user, pwd) def main(args: Array[String]): Unit = { //创建对象，调用apply方法 val demo = MysqlDemo() //导入MySQLUtil包 import MysqlUtil._ //调用创建连接的方法 demo.conn() // 调用释放资源方法 demo.close(connection)}Util则需要先初始化数据库连接，注册驱动，得到数据库连接，释放资源
import java.sql.{Connection, DriverManager, PreparedStatement, ResultSet}object MysqlUtil { implicit class MysqlOp(obj: MysqlDemo) { //初始化数据连接 private var connection: Connection = _ def conn(): Connection = { //注册driver Class.forName(obj.driver) //得到数据库连接 val connection: Connection = DriverManager.getConnection(obj.url, obj.user, obj.password) connection } //释放资源 def close(conn: Connection): Unit = { if (conn != null) { conn.close() } }}准备工作已做完下面要实现对数据库的增删查改
添加数据
方法一
//Util代码//添加数据方法一 def insertStudent: Int = { val insertSqlStr = "insert into student(name, age, gender, telephone, email, classid)" + "values ('周七', 6, '男', '13888888888', '346497@qq.com', 2)" val i: Int = conn().createStatement.executeUpdate(insertSqlStr) i }//Demo测试代码 //添加数据方法一 val i: Int = demo.insertStudent if (i == 1) { println("添加成功") } else if (i == 0) { println("添加失败") }方法二
//Util代码 //添加数据方法二 def insertStudent(name: String, age: Int, gender: String, telephone: String, email: String, classid: Int): Int = { val insertSqlStr = "insert into student(id,name, age, gender, telephone, email, classid)" + "values (null,?,?,?,?,?,?)" val preStmt: PreparedStatement = conn().prepareStatement(insertSqlStr) preStmt.setString(1, name) preStmt.setInt(2, age) preStmt.setString(3, gender) preStmt.setString(4, telephone) preStmt.setString(5, email) preStmt.setInt(6, classid) val i: Int = preStmt.executeUpdate() i }//Demo测试代码 //添加数据方法二 val i: Int = demo.insertStudent("aaa", 18, "男", "12345678910", "34649756@qq.com", 1) if (i == 1) { println("添加成功") } else if (i == 0) { println("添加失败") }删除数据
//Util代码 def deleteStudent(id: Int): Int = { val deleteSql = "delete from student where id= ?" val preStmt: PreparedStatement = conn().prepareStatement(deleteSql) preStmt.setInt(1, id) val i: Int = preStmt.executeUpdate() i }//Demo测试代码 val i: Int = demo.deleteStudent(21) if (i == 1) { println("删除成功") } else if (i == 0) { println("删除失败") }查询数据
//Util代码 def selectStudent: Unit = { val selectSql = "select id,name, age, gender, telephone, email, classid from student" val rs: ResultSet = conn().createStatement().executeQuery(selectSql) println("学号\t姓名\t年龄\t性别\t手机号\t邮箱\t班级编号") while (rs.next()) { val id: Int = rs.getInt("id") val name: String = rs.getString("name") val age: Int = rs.getInt("age") val gender: String = rs.getString("gender") val telephone: String = rs.getString("telephone") val email: String = rs.getString("email") val classid: String = rs.getString("classid") println(id + "\t" + name + "\t" + age + "\t" + gender + "\t" + telephone + "\t" + email + "\t" + classid) } }//Demo测试代码 demo.selectStudent修改数据
//Util代码 def updateStudent(id: Int, name: String, age: Int, gender: String, telephone: String, email: String, classid: Int): Int = { val updateSql = "update student set name=?," + "age=?, " + "gender=?," + "telephone=?," + "email=?, " + "classid=? where id=?" val preStmt: PreparedStatement = conn().prepareStatement(updateSql) preStmt.setString(1, name) preStmt.setInt(2, age) preStmt.setString(3, gender) preStmt.setString(4, telephone) preStmt.setString(5, email) preStmt.setInt(6, classid) preStmt.setInt(7, id) val i: Int = preStmt.executeUpdate() i }//Demo测试代码 val i: Int = demo.updateStudent(22, "test", 25, "女", "123456789", "369852@qq.com", 2) if (i == 1) { println("修改成功") } else if (i == 0) { println("修改失败") }完整代码
MysqlUtil代码
import java.sql.{Connection, DriverManager, PreparedStatement, ResultSet}object MysqlUtil { implicit class MysqlOp(obj: MysqlDemo) { //初始化数据连接 private var connection: Connection = _ def conn(): Connection = { //注册driver Class.forName(obj.driver) //得到数据库连接 val connection: Connection = DriverManager.getConnection(obj.url, obj.user, obj.password) connection } //释放资源 def close(conn: Connection): Unit = { if (conn != null) { conn.close() } } //添加数据方法一 def insertStudent: Int = { val insertSqlStr = "insert into student(name, age, gender, telephone, email, classid)" + "values ('bbb', 6, '男', '13852277346', '3464975236@qq.com', 2)" val i: Int = conn().createStatement.executeUpdate(insertSqlStr) i } //添加数据方法二 def insertStudent(name: String, age: Int, gender: String, telephone: String, email: String, classid: Int): Int = { val insertSqlStr = "insert into student(id,name, age, gender, telephone, email, classid)" + "values (null,?,?,?,?,?,?)" val preStmt: PreparedStatement = conn().prepareStatement(insertSqlStr) preStmt.setString(1, name) preStmt.setInt(2, age) preStmt.setString(3, gender) preStmt.setString(4, telephone) preStmt.setString(5, email) preStmt.setInt(6, classid) val i: Int = preStmt.executeUpdate() i } //删除数据 def deleteStudent(id: Int): Int = { val deleteSql = "delete from student where id= ?" val preStmt: PreparedStatement = conn().prepareStatement(deleteSql) preStmt.setInt(1, id) val i: Int = preStmt.executeUpdate() i } //修改数据 def updateStudent(id: Int, name: String, age: Int, gender: String, telephone: String, email: String, classid: Int): Int = { val updateSql = "update student set name=?," + "age=?, " + "gender=?," + "telephone=?," + "email=?, " + "classid=? where id=?" val preStmt: PreparedStatement = conn().prepareStatement(updateSql) preStmt.setString(1, name) preStmt.setInt(2, age) preStmt.setString(3, gender) preStmt.setString(4, telephone) preStmt.setString(5, email) preStmt.setInt(6, classid) preStmt.setInt(7, id) val i: Int = preStmt.executeUpdate() i } //查询数据 def selectStudent: Unit = { val selectSql = "select id,name, age, gender, telephone, email, classid from student" val rs: ResultSet = conn().createStatement().executeQuery(selectSql) println("学号\t姓名\t年龄\t性别\t手机号\t邮箱\t班级编号") while (rs.next()) { val id: Int = rs.getInt("id") val name: String = rs.getString("name") val age: Int = rs.getInt("age") val gender: String = rs.getString("gender") val telephone: String = rs.getString("telephone") val email: String = rs.getString("email") val classid: String = rs.getString("classid") println(id + "\t" + name + "\t" + age + "\t" + gender + "\t" + telephone + "\t" + email + "\t" + classid) } } }}MysqlDemo代码
import java.sql.Connectionclass MysqlDemo { // 连接数据库 底层原理还是jdbc //驱动名称 var driver = "com.mysql.cj.jdbc.Driver" // 访问MySQL服务器，通过3306端口访问mysql数据库 var url = "jdbc:mysql://192.168.152.184:3306/exam" //用户名 var user = "root" //密码 var password = "123456" //辅助构造器 def this(driver: String, url: String, user: String, pwd: String) { this() this.driver = driver this.url = url this.user = user this.password = pwd }}object MysqlDemo { // 实现apply方法 def apply(): MysqlDemo = new MysqlDemo() def apply(driver: String, url: String, user: String, pwd: String): MysqlDemo = new MysqlDemo(driver, url, user, pwd) def main(args: Array[String]): Unit = { //创建对象，调用apply方法 val demo = MysqlDemo() //导入MySQLUtil包 import MysqlUtil._ //调用创建连接的方法 val connection: Connection = demo.conn() // 调用释放资源方法 demo.close(connection) //添加数据方法一 val i: Int = demo.insertStudent if (i == 1) { println("添加成功") } else if (i == 0) { println("添加失败") } //添加数据方法二 val i: Int = demo.insertStudent("aaa", 18, "男", "12345678910", "34649756@qq.com", 1) if (i == 1) { println("添加成功") } else if (i == 0) { println("添加失败") } //查询数据 demo.selectStudent // 修改数据 val i: Int = demo.updateStudent(22, "test", 25, "女", "123456789", "369852@qq.com", 2) if (i == 1) { println("修改成功") } else if (i == 0) { println("修改失败") } //删除数据 val i: Int = demo.deleteStudent(21) if (i == 1) { println("删除成功") } else if (i == 0) { println("删除失败") } }}感谢各位的阅读，以上就是“Java Scala怎么实现数据库增删查改操作”的内容了，经过本文的学习后，相信大家对Java Scala怎么实现数据库增删查改操作这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！
