编写scala根据dwd层usercontinueorder表统计在两天内连续下单并且下单金额保持增长的用户，存入MySQL数据库shtd_result的usercontinueorder表

假设dwd层usercontinueorder表结构如下：

| 字段名 | 类型 | 说明 |
| --- | --- | --- |
| user_id | string | 用户ID |
| order_date | string | 下单日期 |
| order_amount | double | 下单金额 |

首先，我们需要编写一个SQL语句来筛选出在两天内连续下单的用户，并计算他们的下单金额增长率。SQL语句如下：

SELECT
    t1.user_id,
    t2.order_date AS start_date,
    t1.order_date AS end_date,
    (t1.order_amount - t2.order_amount) / t2.order_amount AS amount_growth_rate
FROM
    dwd.usercontinueorder t1
    JOIN dwd.usercontinueorder t2 ON t1.user_id = t2.user_id
WHERE
    t1.order_date = date_add(t2.order_date, INTERVAL 1 DAY)
    AND t1.order_amount > t2.order_amount

接下来，我们可以使用Spark将查询结果写入MySQL数据库。完整的Scala代码如下：

import org.apache.spark.sql.SparkSession

object UserContinueOrder {
  def main(args: Array[String]): Unit = {
    val spark = SparkSession.builder()
      .appName("UserContinueOrder")
      .getOrCreate()

    // 读取dwd层usercontinueorder表
    val usercontinueorder = spark.read
      .format("jdbc")
      .option("url", "jdbc:mysql://localhost:3306/shtd?useSSL=false")
      .option("driver", "com.mysql.jdbc.Driver")
      .option("dbtable", "dwd.usercontinueorder")
      .option("user", "root")
      .option("password", "root")
      .load()

    // 注册为临时表
    usercontinueorder.createOrReplaceTempView("usercontinueorder")

    // 查询连续下单并下单金额保持增长的用户
    val result = spark.sql(
      """
        |SELECT
        |    t1.user_id,
        |    t2.order_date AS start_date,
        |    t1.order_date AS end_date,
        |    (t1.order_amount - t2.order_amount) / t2.order_amount AS amount_growth_rate
        |FROM
        |    usercontinueorder t1
        |    JOIN usercontinueorder t2 ON t1.user_id = t2.user_id
        |WHERE
        |    t1.order_date = date_add(t2.order_date, INTERVAL 1 DAY)
        |    AND t1.order_amount > t2.order_amount
        |""".stripMargin)

    // 写入MySQL数据库
    result.write
      .format("jdbc")
      .option("url", "jdbc:mysql://localhost:3306/shtd?useSSL=false")
      .option("driver", "com.mysql.jdbc.Driver")
      .option("dbtable", "shtd_result.usercontinueorder")
      .option("user", "root")
      .option("password", "root")
      .save()

    spark.stop()
  }
}

注意，代码中需要替换MySQL数据库的连接信息和认证信息。同时，还需要将MySQL驱动程序的JAR包添加到项目中以便在Spark中使用。