使用 pyodbc 查询数据库

以下示例会话将 pyodbc 与 Vertica ODBC 驱动程序结合使用，以将 Python 连接到 Vertica 数据库。

示例脚本

以下示例脚本显示了如何使用 Python 3、pyodbc 和 ODBC DSN 查询 Vertica。


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()

生成的输出如下所示：

(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)

注意

对于未命名的主键约束，SQLPrimaryKeys 将返回主键 (pk_name) 列中的表名。例如：

  • 未命名主键：

    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"

  • 已命名主键：

    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"

Micro Focus 建议对约束进行命名。

另请参阅