Python clickhouse-driver 类库使用学习总结

实践环境

python3 .9.13

clickhouse-driver 0.2.9

实践操作

# -*- coding:utf-8 -*-import clickhouse_driverif __name__ == '__main__':host = '192.168.88.131'port = 9000 # 注意，不能使用默认的8123username = 'testacc'password = 'test1234'database = 'default'# 连接方式1# conn = clickhouse_driver.connect(database = database,#                                  user = username,#                                  password=password,#                                  host = host,#                                  port = port)# 连接方式2connection_str = f'clickhouse://{username}:{password}@{host}:{port}/{database}'conn = clickhouse_driver.connect(connection_str)cursor = conn.cursor()cursor.execute('SHOW TABLES')res = cursor.fetchall()print(res) # 输出形如 [('table1',), ('test',)]# 删除表cursor.execute('DROP TABLE IF EXISTS test')print(cursor.fetchall()) # 输出:[]cursor.execute('CREATE TABLE test (x Int32) ENGINE = Memory')print(cursor.fetchall()) # 输出:[]#cursor.executemany('INSERT INTO test (x) VALUES', [{'x': 100}])print(cursor.rowcount) # 获取execute* 产生记录数 输出：1#cursor.executemany('INSERT INTO test (x) VALUES', [[200]])print(cursor.rowcount)  # 输出：1#cursor.execute('INSERT INTO test (x) SELECT * FROM system.numbers LIMIT %(limit)s', {'limit': 3})print(cursor.rowcount)  # 输出：1cursor.execute('SELECT sum(x) AS sum_value FROM test')print(cursor.rowcount)  # 输出：1print(cursor.columns_with_types) # 获取查询列名及类型，输出：[('sum_value', 'Int64')]cursor.execute('SELECT * FROM test')print(cursor.rowcount)  # 输出：5print(cursor.columns_with_types) # 输出：[('x', 'Int32')]res = cursor.fetchall()print(res) # 输出：[(100,), (200,), (0,), (1,), (2,)]print(cursor.fetchone()) #输出：None#############################cursor.execute('SELECT * FROM test')print(cursor.fetchone())  # 输出：(100,)# 仅取3条print(cursor.fetchmany(3))  # 输出：[(200,), (0,), (1,)]#############################cursor.execute('SELECT * FROM test')print(cursor.fetchone())  # 输出：(100,)print(cursor.fetchall())  # 输出：[(200,), (0,), (1,), (2,)]cursor.close()conn.close()

说明：

conn = clickhouse_driver.connect(connection_str)

connection_str：

'clickhouse://[{username}:{password}@]{host}[:{port}][/{database}]'

其中，{database}默认为default

参考链接

https://pypi.org/project/clickhouse-driver/#description

https://clickhouse-driver.readthedocs.io/en/latest/dbapi.html#clickhouse_driver.dbapi.connect

https://clickhouse-driver.readthedocs.io/en/latest/dbapi.html#cursor