该文主要展示的是spark sql 例子
（内容是找了份oracle的例子，翻译成spark sql的）
1、需要准备好四张表，既四个文本文件逗号分隔
2、为这四张表创建好schema，并注册成表
3、时间处理有小部分改动
准备的四张表
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四张表中的数据
Teacher
884,zhagnxueyou,female,1980/2/10,Assistant professor,department of computer
856,liudehua,female,1980/12/10,professor,department of electronic engineering
825,liming,female,1980/1/10,advandced professor,department of computer
831,zhourunfa,female,1981/12/10,jonior professor,department of electronic engineering
Student
108,ceng hua,male,1977/9/1,95033
105,zhangsan,male,1975/10/22,95031
107,wangli,female,1976/1/8,95033
101,lili,male,1978/5/14,95033
109,wangfang,female,1979/5/10,95031
103,lijun,male,1974/5/21,95031
Score
103,3-245,86
105,3-245,75
109,3-245,68
103,3-105,92
105,3-105,88
109,3-105,76
101,3-105,64
107,3-105,91
108,3-105,78
101,6-166,85
107,6-166,79
108,6-166,81
Course
3-105,introduction to computer,825
3-245,the operating system,804
6-166,the digital circuit,856
9-888,higher math,831
maven
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.11</artifactId>
<version>2.3.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql -->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>2.3.1</version>
</dependency>
例子代码，粘贴可用，注意注释掉不需要的地方即可
import org.apache.spark.sql.{Row, SparkSession}
import org.apache.spark.sql.types._
import scala.collection.mutable
import java.text.SimpleDateFormat
/**
* 2017/05/26
* CDP
*/
object SparkSqlExample1 {
def main(args: Array[String]): Unit = {
/** ***************************************************************************************************************
* sparksession
*/
val spark = SparkSession
.builder()
.master("local")
.appName("test")
.config("spark.sql.shuffle.partitions", "5")
.getOrCreate()
/** ***************************************************************************************************************
* 表结构
*/
val StudentSchema: StructType = StructType(mutable.ArraySeq( //学生表
StructField("Sno", StringType, nullable = false), //学号
StructField("Sname", StringType, nullable = false), //学生姓名
StructField("Ssex", StringType, nullable = false), //学生性别
StructField("Sbirthday", StringType, nullable = true), //学生出生年月
StructField("SClass", StringType, nullable = true) //学生所在班级
))
val CourseSchema: StructType = StructType(mutable.ArraySeq( //课程表
StructField("Cno", StringType, nullable = false), //课程号
StructField("Cname", StringType, nullable = false), //课程名称
StructField("Tno", StringType, nullable = false) //教工编号
))
val ScoreSchema: StructType = StructType(mutable.ArraySeq( //成绩表
StructField("Sno", StringType, nullable = false), //学号（外键）
StructField("Cno", StringType, nullable = false), //课程号（外键）
StructField("Degree", IntegerType, nullable = true) //成绩
))
val TeacherSchema: StructType = StructType(mutable.ArraySeq( //教师表
StructField("Tno", StringType, nullable = false), //教工编号（主键）
StructField("Tname", StringType, nullable = false), //教工姓名
StructField("Tsex", StringType, nullable = false), //教工性别
StructField("Tbirthday", StringType, nullable = true), //教工出生年月
StructField("Prof", StringType, nullable = true), //职称
StructField("Depart", StringType, nullable = false) //教工所在部门
))
/** ***************************************************************************************************************
* 获取当前时间函数
*/
def getDate(time: String) = {
val now: Long=System.currentTimeMillis()
var df: SimpleDateFormat = new SimpleDateFormat(time)
df.format(now)
}
/** ***************************************************************************************************************
* 读取数据
*/
val StudentData = spark.sparkContext.textFile("input/sqltable/Student").map{
lines =>
val line = lines.split(",")
Row(line(0),line(1),line(2),line(3),line(4))
}
val CourseData = spark.sparkContext.textFile("input/sqltable/Course").map{
lines =>
val line = lines.split(",")
Row(line(0),line(1),line(2))
}
val ScoreData = spark.sparkContext.textFile("input/sqltable/Score").map{
lines =>
val line = lines.split(",")
Row(line(0),line(1),line(2).toInt)
}
val TeacherData = spark.sparkContext.textFile("input/sqltable/Teacher").map{
lines =>
val line = lines.split(",")
Row(line(0),line(1),line(2),line(3),line(4),line(5))
}
/** ***************************************************************************************************************
* 转换成表
*/
val StudentTable = spark.createDataFrame(StudentData, StudentSchema)
StudentTable.createOrReplaceTempView("Student")
val CourseTable = spark.createDataFrame(CourseData, CourseSchema)
CourseTable.createOrReplaceTempView("Course")
val ScoreTable = spark.createDataFrame(ScoreData, ScoreSchema)
ScoreTable.createOrReplaceTempView("Score")
val TeacherTable = spark.createDataFrame(TeacherData, TeacherSchema)
TeacherTable.createOrReplaceTempView("Teacher")
/** ***************************************************************************************************************
* 走sql节奏
* 表名，字段名，区分大小写
*/
////1、 查询Student表中的所有记录的Sname、Ssex和Class列。
spark.sql("SELECT sname, ssex, sclass FROM Student").show()
////2、 查询教师所有的单位即不重复的Depart列。
spark.sql("SELECT DISTINCT depart FROM Teacher").show()
////3、 查询Student表的所有记录
spark.sql("SELECT * FROM Student").show()
////4、 查询Score表中成绩在60到80之间的所有记录。
//spark.sql("SELECT * FROM Score WHERE degree BETWEEN 60 and 80").show()
spark.sql("SELECT * FROM Score WHERE degree >= 60 and degree <= 80").show()
////5、 查询Score表中成绩为85，86或88的记录。
spark.sql("SELECT * FROM Score WHERE degree = '85' OR degree = '86' OR degree = '88'").show()
////6、 查询Student表中“95031”班或性别为“女”的同学记录。
spark.sql("SELECT * FROM Student WHERE sclass = '95031' OR ssex = 'female'").show()
////7、 以Class降序,升序查询Student表的所有记录。
spark.sql("SELECT * FROM Student ORDER BY sclass DESC").show()
spark.sql("SELECT * FROM Student ORDER BY sclass").show()
////8、 以Cno升序、Degree降序查询Score表的所有记录。
spark.sql("SELECT * FROM Score t ORDER BY t.sno ASC, t.degree DESC").show()
////9、 查询“95031”班的学生人数。
spark.sql("SELECT t.sclass totalnum FROM Student t WHERE sclass = '95031'").show()
spark.sql("SELECT t.sclass AS totalnum FROM Student t WHERE sclass = '95031'").show()
////10、 查询Score表中的最高分的学生学号和课程号。（子查询或者排序）
//// oracle => WHERE rownum = 1
//// spark sql => LIMIT 1
spark.sql("SELECT * FROM (SELECT * FROM Score ORDER BY degree DESC LIMIT 1)").show()
spark.sql("SELECT t.sno, t.cno FROM Score t ORDER BY degree DESC").show()
spark.sql("SELECT * FROM Score WHERE degree IN(SELECT MAX(degree) FROM Score t)").show()
////11、 查询每门课的平均成绩。
spark.sql("SELECT AVG(degree) average FROM Score t WHERE cno = '3-245'").show()
spark.sql("SELECT AVG(degree) average FROM Score WHERE cno = '3-105'").show()
spark.sql("SELECT AVG(degree) average FROM Score WHERE cno = '6-166'").show()
spark.sql("SELECT cno, AVG(degree) FROM Score t GROUP BY cno").show()
////12、查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。
spark.sql("SELECT cno, AVG(degree) FROM Score WHERE cno LIKE '3%' GROUP BY cno HAVING COUNT(1) >= 5").show()
////13、查询分数大于70，小于90的Sno列。
spark.sql("SELECT sno FROM Score WHERE degree BETWEEN 70 AND 90").show()
////14、查询所有学生的Sname、Cno和Degree列。
spark.sql("SELECT s.sname, t.cno, t.degree FROM Score t, Student s WHERE t.sno = s.sno").show()
spark.sql("SELECT s.sname, t.cno, t.degree FROM Score t JOIN Student s ON t.sno = s.sno").show()
////15、查询所有学生的Sno、Cname和Degree列。
spark.sql("SELECT s.sname, t.cno, t.degree FROM Score t JOIN Student s ON t.sno = s.sno").show()
////16、查询所有学生的Sname、Cname和Degree列。
spark.sql("SELECT s.sname, t.degree, c.cname FROM Score t, Student s, Course c WHERE t.sno = s.sno AND t.cno = c.cno").show()
spark.sql("SELECT s.sname, t.degree, c.cname FROM Score t " +
"JOIN Student s on t.sno = s.sno " +
"JOIN Course c on c.cno = t.cno").show()
////17、 查询“95033”班学生的平均分。
spark.sql("SELECT AVG(degree) average FROM Score WHERE sno IN (SELECT sno FROM Student WHERE sclass = '95033')").show()
////19、 查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。
spark.sql("SELECT * FROM Score WHERE cno = '3-105' AND degree > (SELECT degree FROM score WHERE sno = '109' AND cno = '3-105')").show()
////20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。
spark.sql("SELECT * FROM Score WHERE sno IN " +
"(SELECT sno FROM Score t GROUP BY t.sno HAVING COUNT(1) > 1) AND degree != (SELECT MAX(degree) FROM Score)").show()
spark.sql("SELECT * FROM Score WHERE degree != (SELECT MAX(degree) FROM Score)").show()
////21、 查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
spark.sql("SELECT * FROM Score t WHERE t.degree > (SELECT degree FROM Score WHERE sno = '109' AND cno = '3-105')").show()
////22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
//// oracle => to_char(t.sbirthday,'yyyy')
//// spark sql => substring(t.sbirthday, 0, 4)
spark.sql("SELECT sno, sname , sbirthday " +
"FROM Student " +
"WHERE substring(sbirthday, 0, 4) = ( " +
"SELECT substring(t.sbirthday, 0, 4) " +
"FROM Student t " +
"WHERE sno = '108')").show()
////23、查询“张旭“教师任课的学生成绩。
spark.sql("SELECT t.tno, c.cno, c.cname, s.degree FROM Teacher t " +
"JOIN Course c ON t.tno = c.tno " +
"JOIN Score s ON c.cno = s.cno WHERE t.tname = 'Zhang xu'").show()
////24、查询选修某课程的同学人数多于5人的教师姓名。
spark.sql("SELECT tname FROM Teacher e " +
"JOIN Course c ON e.tno = c.tno " +
"JOIN(SELECT cno FROM Score GROUP BY cno HAVING COUNT(cno) > 5) t ON c.cno = t.cno").show()
////25、查询95033班和95031班全体学生的记录。
spark.sql("SELECT * FROM Student WHERE sclass IN('95031', '95033')").show()
spark.sql("SELECT * FROM Student WHERE sclass LIKE '9503%'").show()
////26、 查询存在有85分以上成绩的课程Cno.
spark.sql("SELECT cno FROM Score WHERE degree > 85 GROUP BY cno").show()
////27、查询出“计算机系“教师所教课程的成绩表。
spark.sql("SELECT t.sno, t.cno, t.degree FROM Score t " +
"JOIN Course c ON t.cno = c.cno " +
"JOIN Teacher e ON c.tno = e.tno WHERE e.depart = 'department of computer'").show()
////29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
spark.sql("SELECT t.sno, t.cno, degree " +
"FROM SCORE t " +
"WHERE degree > ( " +
"SELECT MIN(degree) " +
"FROM score " +
"WHERE cno = '3-245' " +
") " +
"AND t.cno = '3-105' " +
"ORDER BY degree DESC").show()
////30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的Cno、Sno和Degree.
// oracle方式 spark.sql("select t.sno, t.cno, t.degree from SCORE t where t.degree > select degree from score where cno='3-245' or cno='3-105'").show()
spark.sql("SELECT t.sno, t.cno, t.degree FROM Score t WHERE t.degree > (SELECT MAX(degree) FROM Score WHERE cno = '3-245' ) AND t.cno = '3-105'").show()
////31、 查询所有教师和同学的name、sex和birthday.
spark.sql("SELECT sname, ssex, sbirthday FROM Student " +
"UNION SELECT tname, tsex, tbirthday FROM Teacher").show()
//// 32、查询所有“女”教师和“女”同学的name、sex和birthday. union
spark.sql("SELECT sname, ssex, sbirthday " +
"FROM Student " +
"WHERE ssex = 'female' " +
"UNION " +
"SELECT tname, tsex, tbirthday " +
"FROM Teacher " +
"WHERE tsex = 'female'").show()
////33、 查询成绩比该课程平均成绩低的同学的成绩表。
spark.sql("SELECT s.* " +
"FROM score s " +
"WHERE s.degree < ( " +
"SELECT AVG(degree) " +
"FROM score c " +
"WHERE s.cno = c.cno)").show()
////34、 查询所有任课教师的Tname和Depart. in
spark.sql("SELECT tname, depart " +
"FROM teacher t " +
"WHERE t.tno IN ( " +
"SELECT tno " +
"FROM course c " +
"WHERE c.cno IN (" +
"SELECT cno " +
"FROM score))").show()
////35 、 查询所有未讲课的教师的Tname和Depart. not in
spark.sql("SELECT tname, depart " +
"FROM teacher t " +
"WHERE t.tno NOT IN ( " +
"SELECT tno " +
"FROM course c " +
"WHERE c.cno IN ( " +
"SELECT cno " +
"FROM score))").show()
////36、查询至少有2名男生的班号。 group by, having count
spark.sql("SELECT SClass " +
"FROM Student t " +
"WHERE Ssex = 'male' " +
"GROUP BY SClass " +
"HAVING COUNT(Ssex) >= 2").show()
////37、查询Student表中不姓“王”的同学记录。 not like
spark.sql("SELECT * FROM Student t WHERE Sname NOT LIKE('Wang%')").show()
////38、查询Student表中每个学生的姓名和年龄。
////将函数运用到spark sql中去计算，可以直接拿String的类型计算不需要再转换成数值型 默认是会转换成Double类型计算
spark.sql("SELECT Sname, ("+ getDate("yyyy") +" - substring(sbirthday, 0, 4)) AS age FROM STUDENT t").show()
////浮点型转整型
spark.sql("SELECT Sname, (CAST("+ getDate("yyyy") +" AS INT) - CAST(substring(sbirthday, 0, 4) AS INT)) AS age " +
"FROM Student t").show()
////39、查询Student表中最大和最小的Sbirthday日期值。 时间格式最大值,最小值
spark.sql("SELECT MAX(t.sbirthday) AS maximum FROM Student t").show()
spark.sql("SELECT MIN(t.sbirthday) AS minimum FROM Student t").show()
////40、以班号和年龄从大到小的顺序查询Student表中的全部记录。 查询结果排序
spark.sql("SELECT * " +
"FROM Student " +
"ORDER BY SClass DESC, CAST("+ getDate("yyyy") +" AS INT) - CAST(substring(Sbirthday, 0, 4) AS INT) DESC").show()
////41、查询“男”教师及其所上的课程。 select join
spark.sql("SELECT TSex, CName " +
"FROM Teacher t " +
"JOIN course c ON t.tno = c.tno " +
"WHERE TSex = 'male'").show()
////42、查询最高分同学的Sno、Cno和Degree列。 子查询
spark.sql("SELECT * " +
"FROM Score " +
"WHERE degree = ( " +
"SELECT MAX(degree) " +
"FROM SCORE t)").show()
////43、查询和“李军”同性别的所有同学的Sname.
spark.sql("SELECT sname " +
"FROM STUDENT t " +
"WHERE ssex IN ( " +
"SELECT ssex " +
"FROM student " +
"WHERE sname = 'Liu Jun')").show()
////44、查询和“李军”同性别并同班的同学Sname.
spark.sql("SELECT sname " +
"FROM Student t " +
"WHERE ssex IN ( " +
"SELECT ssex " +
"FROM student " +
"WHERE sname = 'Liu Jun') " +
"AND sclass IN (SELECT sclass " +
"FROM student " +
"WHERE sname = 'Liu Jun')").show()
////45、查询所有选修“计算机导论”课程的“男”同学的成绩表。
spark.sql("SELECT t.sno, t.cno, t.degree " +
"FROM Score t " +
"JOIN Course c ON t.cno = c.cno " +
"JOIN Student s ON s.sno = t.sno " +
"WHERE s.SSex = 'male' " +
"AND c.CName = 'Introduction to computer'").show()
}
}
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