SPARK SQL - 情况下,当再 [英] SPARK SQL - case when then
问题描述
我是新来的火花SQL。是否有一个相当于CASE WHEN'条件',那么0 ELSE 1 END,在SPARK SQL?
I'm new to SPARK-SQL. Is there an equivalent to "CASE WHEN 'CONDITION' THEN 0 ELSE 1 END" in SPARK SQL ?
选择情况下,当1 = 1,则1否则从表0结束
谢谢
斯里达尔
Thanks Sridhar
推荐答案
星火1.2.0之前
支持的语法(这我只是想出去星火1.0.2)似乎是
The supported syntax (which I just tried out on Spark 1.0.2) seems to be
SELECT IF(1=1, 1, 0) FROM table
这最近的线程<一个href=\"http://apache-spark-user-list.1001560.n3.nabble.com/Supported-SQL-syntax-in-Spark-SQL-td9538.html\" rel=\"nofollow\">http://apache-spark-user-list.1001560.n3.nabble.com/Supported-SQL-syntax-in-Spark-SQL-td9538.html链接到SQL解析器源,其可能或可能不由取决于使用Scala您的舒适。在上线70开始(在撰写本文时)关键词的最起码的名单应该有所帮助。
This recent thread http://apache-spark-user-list.1001560.n3.nabble.com/Supported-SQL-syntax-in-Spark-SQL-td9538.html links to the SQL parser source, which may or may not help depending on your comfort with Scala. At the very least the list of keywords starting (at time of writing) on line 70 should help.
下面是直接链接到源方便:<一href=\"https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala\" rel=\"nofollow\">https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala.
Here's the direct link to the source for convenience: https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SqlParser.scala.
更新星火1.2.0及以后
作为火花1.2.0的,较传统的语法被支撑,以响应火花-3813 :搜索CASE WHEN中的<一个href=\"https://github.com/apache/spark/blob/master/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala\"相对=nofollow>测试源。例如:
As of Spark 1.2.0, the more traditional syntax is supported, in response to SPARK-3813: search for "CASE WHEN" in the test source. For example:
SELECT CASE WHEN key = 1 THEN 1 ELSE 2 END FROM testData
为最近更新的地方,从SQL分析器
解析器源现在可以找到<一个href=\"https://github.com/apache/spark/blob/master/sql/catalyst/src/main/antlr4/org/apache/spark/sql/catalyst/parser/SqlBase.g4\"相对=nofollow>这里。
The parser source can now be found here.
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