【问题标题】:How to check if numerical value of a column contains alphabets via SQL query如何通过SQL查询检查列的数值是否包含字母
【发布时间】:2017-10-16 17:55:38
【问题描述】:

我在 AWS S3 中有一个 CSV 文件,该文件正在加载到 AWS Glue,即用于对来自 S3 的源数据文件进行转换。它提供 PySpark 脚本环境。数据看起来有点像这样:

"ID","CNTRY_CD","SUB_ID","PRIME_KEY","DATE"    
"123","IND","25635525","11243749772","2017-10-17"    
"123","IND","25632349","112322abcd","2017-10-17"    
"123","IND","25635234","11243kjsd434","2017-10-17"    
"123","IND","25639822","1124374343","2017-10-17" 

预期的结果应该是这样的:

"123","IND","25632349","112322abcd","2017-10-17"    
"123","IND","25635234","11243kjsd434","2017-10-17"  

我正在处理名称为“PRIME_KEY”的整数类型字段,该字段可能包含导致数据格式错误的字母。

现在的要求是,我需要使用 SQL 查询找出 Integer 类型的主键列是否包含任何字母数字字符,而不仅仅是数字值。到目前为止,我已经尝试了几种正则表达式的变体来做到这一点,如下所示,但没有运气:

SELECT * 
FROM table_name
WHERE column_name IS NOT NULL AND 
CAST(column_name AS VARCHAR(100)) LIKE \'%[0-9a-z0-9]%\'

源脚本:

args = getResolvedOptions(sys.argv, ['JOB_NAME'])
glueContext = GlueContext(SparkContext.getOrCreate())
spark = glueContext.spark_session
job = Job(glueContext)
job.init(args['JOB_NAME'], args)
# s3 output directory
output_dir = "s3://aws-glue-scripts../.."

# Data Catalog: database and table name
db_name = "sampledb"
glue_tbl_name = "sampleTable"

datasource = glueContext.create_dynamic_frame.from_catalog(database = db_name, table_name = glue_tbl_name)
datasource_df = datasource.toDF()
datasource_df.registerTempTable("sample_tbl")
invalid_primarykey_values_df = spark.sql("SELECT * FROM sample_tbl WHERE CAST(PRIME_KEY AS STRING) RLIKE '([a-z]+[0-9]+)|([0-9]+[a-z]+)'")
invalid_primarykey_values_df.show()

这个脚本的输出如下:

+---+--------+--------+------------+---------+ -----------+---------------+

|ID |CNTRY_CD|SUB_ID |PRIME_KEY |DATE |

+---+--------+--------+------------+---------+ -----------+---------------+

|123|IND|25635525|[11243749772,null]|2017-10-17|

|123|IND|25632349|[null,112322ab..|2017-10-17|

|123|IND|25635234|[null,11243kjsd..|2017-10-17|

|123|IND|25639822|[1124374343,null]|2017-10-17|

+--------+--------+--------+------- ---+-----------+---------------+

我已经突出显示了我正在处理的领域的值。它看起来与源数据有些不同。

对此的任何帮助将不胜感激。谢谢

【问题讨论】:

    标签: mysql sql pyspark apache-spark-sql pyspark-sql


    【解决方案1】:

    您可以使用RLIKE

    SELECT * 
    FROM table_name
    WHERE CAST(PRIME_KEY AS STRING) RLIKE '([0-9]+[a-z]+)'
    

    更通用的字母数字过滤器匹配。

    WHERE CAST(PRIME_KEY AS STRING) RLIKE '([a-z]+[0-9]+)|([0-9]+[a-z]+)'
    

    编辑:根据评论

    必要的导入和 udfs

    val spark = SparkSession.builder
      .config(conf)
      .getOrCreate
    
    import org.apache.spark.sql.functions._
    val extract_pkey = udf((x: String) => x.replaceAll("null|\\]|\\[|,", "").trim)
    
    import spark.implicits._
    

    使用 UDF 设置用于测试和清洁的样本数据

    val df = Seq(
      ("123", "IND", "25635525", "[11243749772,null]", "2017-10-17"),
      ("123", "IND", "25632349", "[null,112322abcd]", "2017-10-17"),
      ("123", "IND", "25635234", "[null,11243kjsd434]", "2017-10-17"),
      ("123", "IND", "25639822", "[1124374343,null]", "2017-10-17")
    ).toDF("ID", "CNTRY_CD", "SUB_ID", "PRIME_KEY", "DATE")
      .withColumn("PRIME_KEY", extract_pkey($"PRIME_KEY"))
    
    
    df.registerTempTable("tbl")
    
    spark.sql("SELECT *  FROM tbl WHERE PRIME_KEY RLIKE '([a-z]+[0-9]+)|([0-9]+[a-z]+)'")
      .show(false)
    
    +---+--------+--------+------------+----------+
    |ID |CNTRY_CD|SUB_ID  |PRIME_KEY   |DATE      |
    +---+--------+--------+------------+----------+
    |123|IND     |25632349|112322abcd  |2017-10-17|
    |123|IND     |25635234|11243kjsd434|2017-10-17|
    +---+--------+--------+------------+----------+
    

    【讨论】:

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