[NSE-1079] Set the default escape char for like function

[PHILO-HE]

No description provided.

[github-actions]

#1079

[PHILO-HE]

@jackylee-ch, please do a test with this patch applied.
Currently, we only support "\" escape char, which is the default one in spark. I guess there is no other escape char used on your side, right?

[jackylee-ch]

@jackylee-ch, please do a test with this patch applied.

Thanks for your fix, this works in our environment.

Currently, we only support \ escape char, which is the default one in spark. I guess there is no other escape char used on your side, right?

Yes, I didn't find any other escape char.

[PHILO-HE]

All internal tests passed. @zhouyuan, please have a further check.

[zhouyuan]

@PHILO-HE can this also apply to "rlike"?

[PHILO-HE]

According to the official document, since Spark 2.0, the pattern string for rlike is unescaped by default. So I guess there is no need to consider escape char for rlike if this default config is generally accepted.