聊聊flink Table的Set Operations

栏目: 数据库 · 发布时间: 5年前

内容简介:本文主要研究一下flink Table的Set Operationsflink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/api/table.scalaflink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/plan/logical/operators.scala

本文主要研究一下flink Table的Set Operations

实例

Union

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "a, b, c");
Table result = left.union(right);
  • union方法类似 sql 的union

UnionAll

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "a, b, c");
Table result = left.unionAll(right);
  • unionAll方法类似sql的union all

Intersect

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.intersect(right);
  • intersect方法类似sql的intersect

IntersectAll

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.intersectAll(right);
  • intersectAll方法类似sql的intersect all

Minus

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "a, b, c");
Table result = left.minus(right);
  • minus方法类似sql的except

MinusAll

Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "a, b, c");
Table result = left.minusAll(right);
  • minusAll方法类似sql的except all

In

Table left = ds1.toTable(tableEnv, "a, b, c");
Table right = ds2.toTable(tableEnv, "a");

// using implicit registration
Table result = left.select("a, b, c").where("a.in(" + right + ")");

// using explicit registration
tableEnv.registerTable("RightTable", right);
Table result = left.select("a, b, c").where("a.in(RightTable)");
  • in方法类似sql的in

Table

flink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/api/table.scala

class Table(
    private[flink] val tableEnv: TableEnvironment,
    private[flink] val logicalPlan: LogicalNode) {

  //......

  def union(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException("Only tables from the same TableEnvironment can be unioned.")
    }
    new Table(tableEnv, Union(logicalPlan, right.logicalPlan, all = false).validate(tableEnv))
  }

  def unionAll(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException("Only tables from the same TableEnvironment can be unioned.")
    }
    new Table(tableEnv, Union(logicalPlan, right.logicalPlan, all = true).validate(tableEnv))
  }

  def intersect(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException(
        "Only tables from the same TableEnvironment can be intersected.")
    }
    new Table(tableEnv, Intersect(logicalPlan, right.logicalPlan, all = false).validate(tableEnv))
  }

  def intersectAll(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException(
        "Only tables from the same TableEnvironment can be intersected.")
    }
    new Table(tableEnv, Intersect(logicalPlan, right.logicalPlan, all = true).validate(tableEnv))
  }

  def minus(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException("Only tables from the same TableEnvironment can be " +
        "subtracted.")
    }
    new Table(tableEnv, Minus(logicalPlan, right.logicalPlan, all = false)
      .validate(tableEnv))
  }

  def minusAll(right: Table): Table = {
    // check that right table belongs to the same TableEnvironment
    if (right.tableEnv != this.tableEnv) {
      throw new ValidationException("Only tables from the same TableEnvironment can be " +
        "subtracted.")
    }
    new Table(tableEnv, Minus(logicalPlan, right.logicalPlan, all = true)
      .validate(tableEnv))
  }

  //......
}
  • union及unionAll使用的是Union,intersect及intersectAll使用的是Intersect,minus及minusAll使用的是Minus

Union

flink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/plan/logical/operators.scala

case class Union(left: LogicalNode, right: LogicalNode, all: Boolean) extends BinaryNode {
  override def output: Seq[Attribute] = left.output

  override protected[logical] def construct(relBuilder: RelBuilder): RelBuilder = {
    left.construct(relBuilder)
    right.construct(relBuilder)
    relBuilder.union(all)
  }

  override def validate(tableEnv: TableEnvironment): LogicalNode = {
    if (tableEnv.isInstanceOf[StreamTableEnvironment] && !all) {
      failValidation(s"Union on stream tables is currently not supported.")
    }

    val resolvedUnion = super.validate(tableEnv).asInstanceOf[Union]
    if (left.output.length != right.output.length) {
      failValidation(s"Union two tables of different column sizes:" +
        s" ${left.output.size} and ${right.output.size}")
    }
    val sameSchema = left.output.zip(right.output).forall { case (l, r) =>
      l.resultType == r.resultType
    }
    if (!sameSchema) {
      failValidation(s"Union two tables of different schema:" +
        s" [${left.output.map(a => (a.name, a.resultType)).mkString(", ")}] and" +
        s" [${right.output.map(a => (a.name, a.resultType)).mkString(", ")}]")
    }
    resolvedUnion
  }
}
  • Union继承了BinaryNode,其construct方法通过relBuilder.union来构建union操作

Intersect

flink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/plan/logical/operators.scala

case class Intersect(left: LogicalNode, right: LogicalNode, all: Boolean) extends BinaryNode {
  override def output: Seq[Attribute] = left.output

  override protected[logical] def construct(relBuilder: RelBuilder): RelBuilder = {
    left.construct(relBuilder)
    right.construct(relBuilder)
    relBuilder.intersect(all)
  }

  override def validate(tableEnv: TableEnvironment): LogicalNode = {
    if (tableEnv.isInstanceOf[StreamTableEnvironment]) {
      failValidation(s"Intersect on stream tables is currently not supported.")
    }

    val resolvedIntersect = super.validate(tableEnv).asInstanceOf[Intersect]
    if (left.output.length != right.output.length) {
      failValidation(s"Intersect two tables of different column sizes:" +
        s" ${left.output.size} and ${right.output.size}")
    }
    // allow different column names between tables
    val sameSchema = left.output.zip(right.output).forall { case (l, r) =>
      l.resultType == r.resultType
    }
    if (!sameSchema) {
      failValidation(s"Intersect two tables of different schema:" +
        s" [${left.output.map(a => (a.name, a.resultType)).mkString(", ")}] and" +
        s" [${right.output.map(a => (a.name, a.resultType)).mkString(", ")}]")
    }
    resolvedIntersect
  }
}
  • Intersect继承了BinaryNode,其construct方法通过relBuilder.intersect来构建intersect操作

Minus

flink-table_2.11-1.7.0-sources.jar!/org/apache/flink/table/plan/logical/operators.scala

case class Minus(left: LogicalNode, right: LogicalNode, all: Boolean) extends BinaryNode {
  override def output: Seq[Attribute] = left.output

  override protected[logical] def construct(relBuilder: RelBuilder): RelBuilder = {
    left.construct(relBuilder)
    right.construct(relBuilder)
    relBuilder.minus(all)
  }

  override def validate(tableEnv: TableEnvironment): LogicalNode = {
    if (tableEnv.isInstanceOf[StreamTableEnvironment]) {
      failValidation(s"Minus on stream tables is currently not supported.")
    }

    val resolvedMinus = super.validate(tableEnv).asInstanceOf[Minus]
    if (left.output.length != right.output.length) {
      failValidation(s"Minus two table of different column sizes:" +
        s" ${left.output.size} and ${right.output.size}")
    }
    val sameSchema = left.output.zip(right.output).forall { case (l, r) =>
      l.resultType == r.resultType
    }
    if (!sameSchema) {
      failValidation(s"Minus two table of different schema:" +
        s" [${left.output.map(a => (a.name, a.resultType)).mkString(", ")}] and" +
        s" [${right.output.map(a => (a.name, a.resultType)).mkString(", ")}]")
    }
    resolvedMinus
  }
}
  • Minus继承了BinaryNode,其construct方法通过relBuilder.minus来构建minus操作

小结

in在where子句中

doc


以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持 码农网

查看所有标签

猜你喜欢:

本站部分资源来源于网络,本站转载出于传递更多信息之目的,版权归原作者或者来源机构所有,如转载稿涉及版权问题,请联系我们

Linux内核设计的艺术

Linux内核设计的艺术

新设计团队 / 机械工业出版社华章公司 / 2011-6-20 / 79.00元

关于Linux内核的书已经不计其数,但这本书却是独树一帜的,它的内容代表着Linux内核研究成果的世界顶尖级水平,它在世界范围内首次提出并阐述了操作系统设计的核心指导思想——主奴机制,这是所有操作系统研究者的一笔宝贵财富。本书可能也代表着同类图书的顶尖水平,是一本真正能引导我们较为容易地、极为透彻地理解Linux内核的经典之作,也可能是当前唯一能从本质上指引我们去设计和开发拥有自主知识产权的操作系......一起来看看 《Linux内核设计的艺术》 这本书的介绍吧!

RGB转16进制工具
RGB转16进制工具

RGB HEX 互转工具

随机密码生成器
随机密码生成器

多种字符组合密码

HTML 编码/解码
HTML 编码/解码

HTML 编码/解码