Querying the Database Using Python and pyodbc

The example session below uses pyodbc with the Vertica ODBC driver to connect Python to the Vertica database.

SQLFetchScroll and SQLFetch functions cannot be mixed together in iODBC code. When using pyodbc with the iODBC driver manager, skip cannot be used with the fetchall, fetchone, and fetchmany functions.

Example Script

The following example script shows how to query Vertica using Python 3, pyodbc, and an ODBC DSN.

import pyodbc
cnxn = pyodbc.connect("DSN=VerticaDSN", ansi=True)
cursor = cnxn.cursor()
# create table
cursor.execute("CREATE TABLE TEST("
    "C_ID  INT,"
    "C_FP  FLOAT,"
    "C_VARCHAR VARCHAR(100),"
    "C_DATE DATE, C_TIME TIME,"
    "C_TS TIMESTAMP,"
    "C_BOOL BOOL)")
cursor.execute("INSERT INTO test VALUES(1,1.1,'abcdefg1234567890','1901-01-01','23:12:34','1901-01-01 09:00:09','t')")
cursor.execute("INSERT INTO test VALUES(2,3.4,'zxcasdqwe09876543','1991-11-11','00:00:01','1981-12-31 19:19:19','f')")
cursor.execute("SELECT * FROM TEST")
rows = cursor.fetchall()
for row in rows:
    print(row, end='\n')
cursor.execute("DROP TABLE TEST CASCADE")
cursor.close()
cnxn.close()

The resulting output displays:

(2, 3.4, 'zxcasdqwe09876543', datetime.date(1991, 11, 11), datetime.time(0, 0, 1), datetime.datetime(1981, 12, 31, 19, 19, 19), False)
(1, 1.1, 'abcdefg1234567890', datetime.date(1901, 1, 1), datetime.time(23, 12, 34), datetime.datetime(1901, 1, 1, 9, 0, 9), True)

Notes

SQLPrimaryKeys returns the table name in the primary (pk_name) column for unnamed primary constraints. For example:

  • Unnamed primary key:

    CREATE TABLE schema.test(c INT PRIMARY KEY);

SQLPrimaryKeys
"TABLE_CAT", "TABLE_SCHEM", "TABLE_NAME", "COLUMN_NAME", "KEY_SEQ", "PK_NAME" <Null>, "SCHEMA", "TEST", "C", 1, "TEST"

  • Named primary key:

    CREATE TABLE schema.test(c INT CONSTRAINT pk_1 PRIMARY KEY);

SQLPrimaryKeys
"TABLE_CAT", "TABLE_SCHEM", "TABLE_NAME", "COLUMN_NAME", "KEY_SEQ", "PK_NAME" <Null>, "SCHEMA", "TEST", "C", 1, "PK_1"

OpenText recommends that you name your constraints.

See Also