queryparser-python3 0.1.3

Parses MySQL and translates ADQL to MySQL.

Let’s parse some MySQL and ADQL!

Parsing MySQL

Processing of MySQL queries is done by first creating an instance of the MySQLQueryProcessor class

from queryparser.mysql import MySQLQueryProcessor

qp = MySQLQueryProcessor()

feeding it a MySQL query

sql = "SELECT a FROM db.tab;"
qp.set_query(sql)

and running it with

qp.process_query()

After the processing, the processor object will include columns, functions, and keywords used in the query.

Alternatively, passing the query at initialization automatically processes it.

Translating ADQL

Translation of ADQL queries is done similarly by first creating an instance of the ADQLQueryTranslator class

from queryparser.adql import ADQLQueryTranslator

adql = 'SELECT TOP 100 POINT("ICRS", ra, de) FROM db.tab'
adt = ADQLQueryTranslator(adql)

and calling

adt.to_mysql()

which returns a translated string representing a valid MySQL query if the the ADQL query had no errors. The MySQL query can then be parsed with the MySQLQueryProcessor in the same way as shown above.

Generating the parser from the git repository

To generate the parsers you need python (either 2 or 3), java above version 7, and antlr4 (which has to be installed inside the /usr/local/lib/ or /usr/local/bin/ directories).

After cloning the project, run

make

and a lib directory will be created with the complete source for python2 and python3. After that, run:

python setup.py install

to install the generated parser in you virtual env.

Testing

First, install pytest

` pip install pytest `

then, run the test suite:

` pytest `

TODO

• more Documentation

• ADQL coordinate systems

• ADQL mixed coordinates