[SPARK-SQL] How to pass parameter when running hql script using cli?

[James]

Hello,

I want to execute a hql script through `spark-sql` command, my script
contains:

```
ALTER TABLE xxx
DROP PARTITION (date_key = ${hiveconf:CUR_DATE});
```

when I execute

```
spark-sql -f script.hql -hiveconf CUR_DATE=20150119
```

It throws an error like
```
cannot recognize input near '$' '{' 'hiveconf' in constant
```

I have try on hive and it works. Thus how could I pass a parameter like
date to a hql script?

Alcaid