在spark sql中需要等效的SQL IsNumeric函数 [英] Need the equivalent of SQL IsNumeric function in spark sql

问题描述

就像我们有验证表达式是否为数字的 SQL ISNUMERIC 函数一样，我需要 Spark SQL 中是否有任何等效函数，我试图找到它但无法找到它.请问有人可以提供帮助或建议吗?

Like we have SQL ISNUMERIC Function which validates whether the expression is numeric or not , I need if there is any equivalent function in Spark SQL, I have tried to find it but couldn't get it. Please if someone can help or suggest for the same ?

推荐答案

尝试使用 spark udf，这种方法将帮助您克隆任何函数 -

Try using spark udf, this approach will help you clone any function -

scala> spark.udf.register("IsNumeric", (inpColumn: Int) => BigInt(inpColumn).isInstanceOf[BigInt])
res46: org.apache.spark.sql.expressions.UserDefinedFunction = UserDefinedFunction(<function1>,BooleanType,Some(List(IntegerType)))

scala> spark.sql(s""" select "ABC", IsNumeric(123) as IsNumeric_1  """).show(false)
+---+-----------+
|ABC|IsNumeric_1|
+---+-----------+
|ABC|true       |
+---+-----------+


scala> spark.sql(s""" select "ABC", IsNumeric("ABC") as IsNumeric_1  """).show(false)
+---+-----------+
|ABC|IsNumeric_1|
+---+-----------+
|ABC|null       |
+---+-----------+

这里，如果列值不是整数，上面的函数将返回 null.

Here, above function will return null if column value is not integer.

希望这会有所帮助.

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