queryparser-python3 0.1

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 b;"
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 a,b FROM c"
adt = ADQLQueryTranslator(adql)

and calling

adt.to_mysql()

which returns a translated string.

Examples

There are some example queries in the queryparser/examples directory. Have a look there, edit run.py (just comment out/uncomment the line you want in main) and run it:

python queryparser/examples/run.py

This will parse a number of queries (specified in the corresponding example-files) and print the query, the parsed columns and the parsing time.

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

python make.py

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.

TODO

• more Documentation

• ADQL coordinate systems

• ADQL mixed coordinates