如何使用SQL检索Teradata表中最后插入的行

Question

I have the below multiset teradata table

CREATE MULTISET TABLE pp_scratch.HADOOP_FPTI_DASHBOARD ,NO FALLBACK ,
     NO BEFORE JOURNAL,
     NO AFTER JOURNAL,
     CHECKSUM = DEFAULT,
     DEFAULT MERGEBLOCKRATIO
     (
      job_status VARCHAR(32) CHARACTER SET LATIN NOT CASESPECIFIC NOT NULL,
      current_processing_hr VARCHAR(32) CHARACTER SET LATIN NOT CASESPECIFIC NOT NULL,
      no_of_files_moved VARCHAR(10) CHARACTER SET LATIN NOT CASESPECIFIC NOT NULL)
PRIMARY INDEX upi_HADOOP_FPTI_DASHBOARD ( current_processing_hr );

When I am trying to insert the values it is not in the order I have inserted. If it is in order I have inserted then I will retrieve the value by using order by statement. In this case how to retrieve the last inserted value.

Sample data

Answer 1

Teradata tables are hash partitoned/sorted, there's no way to get the last row unless current_processing_hr is unique.

And you data types are wrong:

• change current_processing_hr to a timestamp(2) default current_timestamp(2) , if you don't insert multiple rows in the same 1/100th second you can use this for the last row
• change no_of_files_moved to INT

Answer 2

What you can do here is add a sequence ( auto increment numeric integer ). For this you would have to alter your table and add a new column ( datatype integer ). This column will automatically increment its counter by 1 with every record you insert. Now, if you order by that new column, you will be able to get the last row which was inserted into the table.