Mysql # comment compliance

[udit19524]

Issue:

• Mysql allows # as a comment for all newline comments
• comments are not striped and the query does not split as well when #<not_space comments> are encountered.
• No space after # and a backtick is not working in harmony to split the sql queries as well

Here are a few examples which can help you recreate the issue:

ideal Scenario with no backtick and space after #:

sql = """# comments1
select `id`
from test_user;
select `id`
from test_user2; """
print("------------comment strip-------------")
query_list = sqlparse.format(sql, strip_comments=True).strip()
print(query_list)

query_list = sqlparse.split(query_list)
print("------------split_list -------------")
print(query_list)```

output:

```------------comment strip-------------
select `id`
from test_user;
select `id`
from test_user2;
------------split_list -------------
['select `id`\nfrom test_user;', 'select `id`\nfrom test_user2;']```

 Scenario with no backtick and no space after #:

```import sqlparse 
sql = """#comments1
select `id`
from test_user;
select `id`
from test_user2; """
print("------------comment strip-------------")
query_list = sqlparse.format(sql, strip_comments=True).strip()
print(query_list)

query_list = sqlparse.split(query_list)
print("------------split_list -------------")
print(query_list)```

output:
```#comments1
select `id`
from test_user;
select `id`
from test_user2;
------------split_list -------------
['#comments1\nselect `id`\nfrom test_user;', 'select `id`\nfrom test_user2;']```

 Scenario with  backtick and no space after #:
```import sqlparse 
sql = """#`comments1`
select `id`
from test_user;
select `id`
from test_user2; """
print("------------comment strip-------------")
query_list = sqlparse.format(sql, strip_comments=True).strip()
print(query_list)

query_list = sqlparse.split(query_list)
print("------------split_list -------------")
print(query_list)```

output:
```------------comment strip-------------
#`comments1`
select `id`
from test_user;
select `id`
from test_user2;
------------split_list -------------
['#`comments1`\nselect `id`\nfrom test_user;\nselect `id`\nfrom test_user2;']```

As you can see when backticks are being introduced the split is not happening correctly based on ;

[andialbrecht]

Right now that conflicts with the XOR operator in PostgreSQL (https://www.postgresql.org/docs/9.4/functions-bitstring.html). See also #539. I've added this issue to the list of issues that need to be taken into consideration when adding options to tell sqlparse which SQL dialect to use.

[udit19524]

That sounds great, do we have a timeline on it, currently I am handling it on my part but would love to see the package handle it as well

[mrmasterplan]

After my PR #693 it should be simple to deploy different syntaxes. What is missing is to expose this on the command line.