验证 sql spark java 的列

Question

Database entry:

id: 9
message: {"Start Date":"11-06-2020","End Date":"11-06-2020"}
Group: NULL

id: 10
message: {"Start Date":"11-06-2020","End Date":"11-06-2020"}
Group: NULL

How can i validate the message column in database and see if the start date is in correct format or not?

My spark java code:

 String sqlQuery="select * from emp"; 
     Dataset<Row> df = spark.read().format("jdbc")
                .option("url", "jdbc:mysql://localhost:3306/employee")
                .option("query",sqlQuery)
                .option("user", "root")
                .option("password", "root")
                .load();

Answer 1

You can put a schema structure for "message" section and extract the start and end date out of it.

And you can create a custom UDF like "isValidTimestamp" to validate the start and end time.

//  Sample code
import datetime
def isValidTimestamp(inputdate):
try:
    datetime.strptime(inputdate, '%Y-%m-%d %H:%M:%S')
    return True
except ValeError:
    return False

Also you can refer to this document for more information on timestamp validation in Spark.

https://databricks.com/blog/2020/07/22/a-comprehensive-look-at-dates-and-timestamps-in-apache-spark-3-0.html