如何在spark sql中执行多行sql

Question

如何在 Spark SQL 中执行冗长的多行 Hive 查询？ 像下面的查询：

val sqlContext = new HiveContext (sc)
val result = sqlContext.sql ("
 select ...
 from ...
");

Answer 1

例如，使用“”“代替

val results = sqlContext.sql ("""
     select ....
     from ....
""");

或者，如果要格式化代码，请使用：

val results = sqlContext.sql ("""
     |select ....
     |from ....
""".stripMargin);

Answer 2

您可以在SQL代码的开头/结尾使用三引号，也可以在每行末尾使用反斜杠。

val results = sqlContext.sql ("""
    create table enta.scd_fullfilled_entitlement as
    select *
    from my_table
    """);

results = sqlContext.sql (" \
    create table enta.scd_fullfilled_entitlement as \
    select * \
    from my_table \
    ")

Answer 3

值得注意的是，长度不是问题，只是写作。 为此，您可以使用“”作为Gaweda建议或仅使用字符串变量，例如通过使用字符串构建器构建它。例如：

val selectElements = Seq("a","b","c")
val builder = StringBuilder.newBuilder
builder.append("select ")
builder.append(selectElements.mkString(","))
builder.append(" where d<10")
val results = sqlContext.sql(builder.toString())

Answer 4

除了上述方法之外，您还可以使用下面提到的方法：

val results = sqlContext.sql("select .... " +
" from .... " +
" where .... " +
" group by ....
");

Answer 5

val query = """(SELECT
      a.AcctBranchName,
    c.CustomerNum,
    c.SourceCustomerId,
    a.SourceAccountId,
    a.AccountNum,
    c.FullName,
    c.LastName,
    c.BirthDate,
    a.Balance,
    case when [RollOverStatus] = 'Y' then 'Yes' Else 'No' end as RollOverStatus
    FROM
    v_Account AS a left join v_Customer AS c
      ON c.CustomerID = a.CustomerID AND c.Businessdate = a.Businessdate
    WHERE
    a.Category = 'Deposit' AND
    c.Businessdate= '2018-11-28'  AND
    isnull(a.Classification,'N/A') IN ('Contractual Account','Non-Term Deposit','Term Deposit')
    AND IsActive = 'Yes' ) tmp """

Answer 6

将您的 sql 写在三重引号内，例如 """ sql 代码 """

df = spark.sql(""" select * 来自 table1 """)

这与 Scala spark 和 Pyspark 相同。