Set variable in hive query

[Ravisankar Mani <rr...@gmail.com>]

Hi everyone,

I assign values for  set variable. Please refer following query

SET Row_Number_0 = 0;
SELECT
            criticid AS criticid,
            sum(rating) as rating,
              ${hiveconf:Row_Number_0}= ${hiveconf:Row_Number_0} + 1  AS
R_N_1
 FROM
GROUP BY recommend_ratings2.criticid
ORDER BY  criticid ASC;

the assign variable(3 or select values) only returns true or false

But the same query returns 1,2,3.........  (row number) in mysql. Could you
please help exact query to return assign values?


Regards,

Ravisankar M R

Re: Set variable in hive query

[gabriel balan <ga...@oracle.com>]

Hi

It seems (see here <https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/Driver.java#L388>) Hive substitutes the variables before parsing the query.
So the query being parsed is actually:

    SELECT
                 criticid AS criticid,
                 sum(rating) as rating,
                   0= 0 + 1  AS R_N_1
      ...

Once the constants are folded, I expect it becomes:

    SELECT
                 criticid AS criticid,
                 sum(rating) as rating,
                   false  AS R_N_1
      ...

hth
GB

On 6/5/2015 7:22 AM, Ravisankar Mani wrote:
> Hi everyone,
>
> I assign values for  set variable. Please refer following query
>
> SET Row_Number_0 = 0;
> SELECT
>             criticid AS criticid,
>             sum(rating) as rating,
>               ${hiveconf:Row_Number_0}= ${hiveconf:Row_Number_0} + 1  AS R_N_1
>  FROM
> GROUP BY recommend_ratings2.criticid
> ORDER BY  criticid ASC;
>
> the assign variable(3 or select values) only returns true or false
>
> But the same query returns 1,2,3.........  (row number) in mysql. Could you please help exact query to return assign values?
>
>
> Regards,
>
> Ravisankar M R

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