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fix(SelectiveMerge): Do not override non-existing entries #396

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41 changes: 36 additions & 5 deletions src/main/scala/com/yotpo/metorikku/code/steps/SelectiveMerge.scala
Original file line number Diff line number Diff line change
Expand Up @@ -3,9 +3,11 @@ package com.yotpo.metorikku.code.steps
import com.yotpo.metorikku.exceptions.MetorikkuException
import org.apache.log4j.{LogManager, Logger}
import org.apache.spark.sql.catalyst.expressions.NamedExpression
import org.apache.spark.sql.{Column, DataFrame}
import org.apache.spark.sql.{Column, DataFrame, Row}
import org.apache.spark.sql.functions._

import scala.collection.mutable.ListBuffer

object SelectiveMerge {
private val message = "You need to send 3 parameters with the names of the dataframes to merge and the key(s) to merge on" +
"(merged df1 into df2 favoring values from df2): df1, df2, Seq[String]"
Expand Down Expand Up @@ -58,8 +60,28 @@ object SelectiveMerge {
}

def merge(df1: DataFrame, df2: DataFrame, joinKeys: Seq[String]): DataFrame = {
val mergedDf = outerJoinWithAliases(df1, df2, joinKeys)
overrideConflictingValues(df1, df2, mergedDf, joinKeys)
val df2NoStaleEntries = removeStaleEntries(df1, df2, joinKeys)
val mergedDf = outerJoinWithAliases(df1, df2NoStaleEntries, joinKeys)
overrideConflictingValues(df1, df2NoStaleEntries, mergedDf, joinKeys)
}

def removeStaleEntries(df1: DataFrame, df2: DataFrame, joinKeys: Seq[String]): DataFrame = {
var df2New = df2
for (key <- joinKeys) {
val diff = df2.select(col(key)).except(df1.select(col(key)))
var toRemoveBuff = new ListBuffer[Row]()

val localIter = diff.toLocalIterator()
while(localIter.hasNext) {
toRemoveBuff += localIter.next()
}

val toRemove = toRemoveBuff.toList.map(r => r.getAs[String](key))

df2New = df2New.filter(!df2New(key).isin(toRemove:_*))
}

df2New
}

def outerJoinWithAliases(df1: DataFrame, df2: DataFrame, joinKeys: Seq[String]): DataFrame = {
Expand Down Expand Up @@ -91,6 +113,8 @@ object SelectiveMerge {
}

def overrideConflictingValues(df1: DataFrame, df2: DataFrame, mergedDf: DataFrame, joinKeys: Seq[String]): DataFrame = {
val df1SchemaNames = df1.schema.map(f => f.name)

val mergedSchema = getMergedSchema(df1, df2, joinKeys)

mergedDf.select(
Expand All @@ -100,9 +124,16 @@ object SelectiveMerge {
val colNameArr = colName.split(colRenamePrefix)
val colNameOrig = if (colNameArr.size > 1) colNameArr(1) else colName

// Belongs to DF2, override.
// Column appears in DF2, override unless the row only belongs to DF1
if (colNameArr.size > 1) {
mergedDf(colName).alias(colNameOrig)
if (df1SchemaNames.contains(colNameOrig)) {
when(mergedDf(colName).isNotNull, mergedDf(colName).cast(df1.schema(colNameOrig).dataType))
.otherwise(df1(colNameOrig))
.alias(colNameOrig)
}
else {
mergedDf(colName).alias(colNameOrig)
}
}
// Is the join key(s)
else if (joinKeys.contains(colName)) {
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -53,57 +53,46 @@ class SelectiveMergeTests extends FunSuite with BeforeAndAfterEach {
showString.invoke(df, 10.asInstanceOf[Object], 20.asInstanceOf[Object], false.asInstanceOf[Object]).asInstanceOf[String]
}

test("Selective merge") {
test("Equal number of columns") {
val sparkSession = SparkSession.builder.appName("test").getOrCreate()
val sqlContext= sparkSession.sqlContext
val sqlContext= new SQLContext(sparkSession.sparkContext)
import sqlContext.implicits._

val employeeData1 = Seq(
("James", 1, 11, 111, 1111),
("Maria", 2, 22, 222, 2222)
("James", 20, 10000),
("Maria", 30, 20000)
)
val df1 = employeeData1.toDF("employee_name", "salary", "age", "fake", "fake2")
val df1 = employeeData1.toDF("employee_name", "age", "salary")

val employeeData2 = Seq(
("James", 1, 33, 333),
("Jen", 4, 44, 444),
("Jeff", 5, 55, 555)
("James", 21, 1),
("Jen", 40, 2)
)
val df2 = employeeData2.toDF("employee_name", "salary", "age", "bonus")
val df2 = employeeData2.toDF("employee_name", "age", "new_formula")

val simpleDataExpectedAfterMerge = Seq(
("James", Integer.valueOf(1) /* Salary */, Integer.valueOf(33) /* age */, Integer.valueOf(111) /* fake */,
Integer.valueOf(1111) /* fake2 */, Integer.valueOf(333) /* bonus */),
("Maria", null.asInstanceOf[Integer] /* Salary */, null.asInstanceOf[Integer] /* age */, Integer.valueOf(222) /* fake */,
Integer.valueOf(2222) /* fake2 */, null.asInstanceOf[Integer] /* bonus */),
("Jen", Integer.valueOf(4) /* Salary */, Integer.valueOf(44) /* age */, null.asInstanceOf[Integer] /* fake */,
null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(444) /* bonus */),
("Jeff", Integer.valueOf(5) /* Salary */, Integer.valueOf(55) /* age */, null.asInstanceOf[Integer] /* fake */,
null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(555) /* bonus */)
("James", new Integer(21) /* age */, new Integer(10000) /* salary */, new Integer(1) /* new formula */),
("Maria", new Integer(30) /* age */, new Integer(20000) /* salary */, null.asInstanceOf[Integer] /* new_formula */)
)
val expectedDf = simpleDataExpectedAfterMerge.toDF("employee_name", "salary", "age", "fake", "fake2", "bonus")
val expectedDf = simpleDataExpectedAfterMerge.toDF("employee_name", "age", "salary", "new_formula")

val simpleDataNotExpectedAfterMerge = Seq(
("James", Integer.valueOf(10) /* Salary */, Integer.valueOf(33) /* age */, Integer.valueOf(111) /* fake */,
Integer.valueOf(1111) /* fake2 */, Integer.valueOf(333) /* bonus */),
("Maria", Integer.valueOf(20) /* Salary */, Integer.valueOf(22) /* age */, Integer.valueOf(222) /* fake */,
Integer.valueOf(2222) /* fake2 */, null.asInstanceOf[Integer] /* bonus */),
("Jen", Integer.valueOf(40) /* Salary */, Integer.valueOf(44) /* age */, null.asInstanceOf[Integer] /* fake */,
null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(444) /* bonus */),
("Jeff", Integer.valueOf(50) /* Salary */, Integer.valueOf(55) /* age */, null.asInstanceOf[Integer] /* fake */,
null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(555) /* bonus */)
("James", new Integer(10) /* age */, new Integer(33) /* salary */, new Integer(111) /* new formula */),
("Maria", new Integer(20) /* age */, new Integer(22) /* salary */, new Integer(222) /* new formula */),
("Jen", new Integer(40) /* age */, new Integer(44) /* salary */, null.asInstanceOf[Integer] /* new formula */),
("Jeff", new Integer(50) /* age */, new Integer(55) /* salary */, null.asInstanceOf[Integer] /* new formula */)
)
val notExpectedDf = simpleDataNotExpectedAfterMerge.toDF("employee_name", "salary", "age", "fake", "fake2", "bonus")
val notExpectedDf = simpleDataNotExpectedAfterMerge.toDF("employee_name", "age", "salary", "new_formula")

val mergedDf = merge(df1, df2, Seq("employee_name"))

assertSuccess(mergedDf, expectedDf, isEqual = true)
assertSuccess(mergedDf, notExpectedDf, isEqual = false)
}

test("String and numbers mixed fields") {
test("Df2 has more columns") {
val sparkSession = SparkSession.builder.appName("test").getOrCreate()
val sqlContext= sparkSession.sqlContext
val sqlContext= new SQLContext(sparkSession.sparkContext)
import sqlContext.implicits._

val employeeData1 = Seq(
Expand All @@ -120,14 +109,10 @@ class SelectiveMergeTests extends FunSuite with BeforeAndAfterEach {
val df2 = employeeData2.toDF("employee_name", "salary", "age", "bonus")

val simpleDataExpectedAfterMerge = Seq(
("James", "Sharon" /* Last Name */, Integer.valueOf(1) /* Salary */, Integer.valueOf(33) /* age */,
Integer.valueOf(111) /* fake */, Integer.valueOf(1111) /* fake2 */, Integer.valueOf(333) /* bonus */),
("Maria", "Bob" /* Last Name */, null.asInstanceOf[Integer] /* Salary */, null.asInstanceOf[Integer] /* age */,
Integer.valueOf(222) /* fake */, Integer.valueOf(2222) /* fake2 */, null.asInstanceOf[Integer] /* bonus */),
("Jen", null.asInstanceOf[String] /* Last Name */, Integer.valueOf(4) /* Salary */, Integer.valueOf(44) /* age */,
null.asInstanceOf[Integer] /* fake */, null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(444) /* bonus */),
("Jeff", null.asInstanceOf[String] /* Last Name */, Integer.valueOf(5) /* Salary */, Integer.valueOf(55) /* age */,
null.asInstanceOf[Integer] /* fake */, null.asInstanceOf[Integer] /* fake2 */, Integer.valueOf(555) /* bonus */)
("James", "Sharon" /* Last Name */, new Integer(1) /* Salary */, new Integer(33) /* age */,
new Integer(111) /* fake */, new Integer(1111) /* fake2 */, new Integer(333) /* bonus */),
("Maria", "Bob" /* Last Name */, null.asInstanceOf[Integer] /* Salary */, new Integer(22) /* age */,
new Integer(222) /* fake */, new Integer(2222) /* fake2 */, null.asInstanceOf[Integer] /* bonus */)
)
val expectedDf = simpleDataExpectedAfterMerge.toDF("employee_name", "last_name", "salary", "age", "fake", "fake2", "bonus")

Expand All @@ -136,9 +121,9 @@ class SelectiveMergeTests extends FunSuite with BeforeAndAfterEach {
assertSuccess(mergedDf, expectedDf, isEqual = true)
}

test("df2 has more columns") {
test("df1 has more columns") {
val sparkSession = SparkSession.builder.appName("test").getOrCreate()
val sqlContext= sparkSession.sqlContext
val sqlContext= new SQLContext(sparkSession.sparkContext)
import sqlContext.implicits._

val employeeData1 = Seq(
Expand All @@ -155,13 +140,11 @@ class SelectiveMergeTests extends FunSuite with BeforeAndAfterEach {
val df2 = employeeData2.toDF("employee_name", "salary", "age", "bonus", "fake")

val simpleDataExpectedAfterMerge = Seq(
("James", Integer.valueOf(10) /* Salary */, Integer.valueOf(33) /* age */,
Integer.valueOf(333) /* Bonus */, Integer.valueOf(3333) /* fake */),
("Maria", null.asInstanceOf[Integer] /* Salary */, null.asInstanceOf[Integer] /* age */,
("James", new Integer(10) /* Salary */, new Integer(33) /* age */,
new Integer(333) /* Bonus */, new Integer(3333) /* fake */),
("Maria", new Integer(2) /* Salary */, new Integer(22) /* age */,
null.asInstanceOf[Integer] /* Bonus */, null.asInstanceOf[Integer] /* fake */),
("Jen", Integer.valueOf(4) /* Salary */, Integer.valueOf(44) /* age */,
Integer.valueOf(444) /* Bonus */, Integer.valueOf(4444) /* fake */),
("Albert", null.asInstanceOf[Integer] /* Salary */, null.asInstanceOf[Integer] /* age */,
("Albert", new Integer(3) /* Salary */, new Integer(33) /* age */,
null.asInstanceOf[Integer] /* Bonus */, null.asInstanceOf[Integer] /* fake */)
)
val expectedDf = simpleDataExpectedAfterMerge.toDF("employee_name", "salary", "age", "bonus", "fake")
Expand Down