我尝试使用 sqlalchemy 通过 Pandas 附加我的 vertica(SQL 类型)表
import pandas as pd
import sqlalchemy as sa
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为vertica创建引擎:
def get_engine(base):
engine = sa.create_engine("{sys}+{dri}://{user}:" + \
"{password}@{host}:{port}/{database}".format(**login[base]))
return engine
engine = get_engine('vertica')
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为了清楚起见,一个简单的查询:
table = '***'
sql =\
'''
select *
from public.{table}
'''.format(table=table)
connection = engine.connect()
data = pd.read_sql(sql, connection)
connection.close()
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数据不为空:
print(len(data))
569955
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并尝试写入同一张表:
fields = list(data.columns)
connection = engine.connect()
data.to_sql(table, connection, schema='public', index=False, if_exists='append', chunksize=30000,
dtype={fields[0]:sa.types.Integer,
fields[1]:sa.types.VARCHAR,
fields[2]:sa.types.Integer,
fields[3]:sa.types.Integer,
fields[4]:sa.types.Integer,
fields[5]:sa.types.VARCHAR,
fields[6]:sa.types.VARCHAR,
fields[7]:sa.types.VARCHAR,
fields[8]:sa.types.VARCHAR,
fields[9]:sa.types.VARCHAR,
fields[10]:sa.types.VARCHAR,
fields[11]:sa.types.VARCHAR,
fields[12]:sa.types.DateTime
})
connection.close() …Run Code Online (Sandbox Code Playgroud)