An example of using the JayDeBeAPI for a JDBC connection to Apache Drill

drill_jdbc.py

import jaydebeapi

def ResultIter(cursor, arraysize=1000):
    'An iterator that uses fetchmany to keep memory usage down'
    while True:
        results = cursor.fetchmany(arraysize)
        if not results:
            break
        for result in results:
            yield result


class RegisterColumnNames(object):
    def __init__(self, cursor, row):
        for (attr, val) in zip((d[0] for d in cursor.description), row):
            setattr(self, attr, val)

drill_conn = None
try:
    drill_conn = jaydebeapi.connect(
        "org.apache.drill.jdbc.Driver",
        "jdbc:drill:drillbit=localhost",
        [],
        "/path/to/drill-jdbc-all-1.17.0.jar"
    )
except Exception as e:
    # A problem in the JPype bootstrapping requires us to retry this?
    print("Caught exception {}. Trying again".format(e))
    drill_conn = jaydebeapi.connect(
        "org.apache.drill.jdbc.Driver",
        "jdbc:drill:drillbit=localhost",
        [],
        "/path/to/drill-jdbc-all-1.17.0.jar"
    )
            
cursor = drill_conn.cursor()
cursor.execute("SELECT * FROM a_large_table")
for result in ResultIter(cursor):
    row = RegisterColumnNames(cursor, result)
    # a_large_table has a column named "my_value"
    my_value = row.my_value