Consider the following rules and guidelines when you configure a Sqoop source in a mapping:
To override the default query in a mapping with an advanced query, you must define a mapping parameter and set its value to $CONDITIONS. You must then include $CONDITIONS in the WHERE clause of the custom query.
If you define a custom query, you must verify that the metadata of the custom query matches the metadata of the source object. Otherwise, Sqoop might write blank values to the target.
If you specify a sort condition in a mapping, the Data Integration Service ignores the Order By condition.
You cannot sort columns in a Sqoop source.
You cannot read distinct rows from a Sqoop source.
When you enable OraOop and configure an advanced query to read data from an Oracle source through Sqoop, the mapping fails on the Spark engine.
When you read data from an Oracle source through Sqoop and run the mapping on the Blaze or Spark engine, Sqoop treats the owner name as case sensitive.
Sqoop uses the values that you configure in the
fields of the JDBC connection. If you configure the --username or --password argument in a JDBC connection or mapping, Sqoop ignores the arguments. If you create a password file to access a database, Sqoop ignores the password file.