序
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);复制代码
- 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);复制代码
- 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);复制代码
- 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);复制代码
- 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);复制代码
- 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);复制代码
- 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 registrationTable result = left.select("a, b, c").where("a.in(" + right + ")");// using explicit registrationtableEnv.registerTable("RightTable", right);Table result = left.select("a, b, c").where("a.in(RightTable)");复制代码 - 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)) } //......}复制代码 - 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 }}复制代码 - 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 }}复制代码 - 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 }}复制代码 - Minus继承了BinaryNode，其construct方法通过relBuilder.minus来构建minus操作
小结
- Table对Set提供了union、unionAll、intersect、intersectAll、minus、minusAll、in(
in在where子句中)操作 - 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继承了BinaryNode，其construct方法通过relBuilder.union来构建union操作；Intersect继承了BinaryNode，其construct方法通过relBuilder.intersect来构建intersect操作；Minus继承了BinaryNode，其construct方法通过relBuilder.minus来构建minus操作