问题描述
我有以下数据框
ipdb> csv_data
country sale date trans_factor
0 India 403171 12/01/2012 1
1 Bhutan 394096 12/01/2012 2
2 Nepal super 12/01/2012 3
3 madhya 355883 12/01/2012 4
4 sudan man 12/01/2012 5
到目前为止,我正在使用下面的代码在表中插入数据,例如如果表已经存在,则将其删除并创建新表
As of now i am using below code to insert data in table, like if table already exists, drop it and create new table
csv_file_path = data_mapping_record.csv_file_path
original_csv_header = pandas.read_csv(csv_file_path).columns.tolist()
csv_data = pandas.read_csv(csv_file_path, skiprows=[0], names=original_csv_header, infer_datetime_format=True)
table_name = data_mapping_record.csv_file_path.split('/')[-1].split('.')[0]
engine = create_engine(
'postgresql://username:password@localhost:5432/pandas_data')
# Delete table if already exits
engine.execute("""DROP TABLE IF EXISTS "%s" """ % (table_name))
# Write the pandas dataframe to database using sqlalchemy and pands.to_sql
csv_data_frame.to_sql(table_name, engine, chunksize=1000)
但是我需要的是不删除表,如果表已经存在,只需将数据追加到已经存在的表中,熊猫to_sql
方法中有什么办法吗?
But what i need is, without deleting the table, if table already exists just append the data to the already existing one, is there any way in pandas to_sql
method ?
推荐答案
IIUC,您可以简单地使用 if_exists='append'
参数:
IIUC you can simply use if_exists='append'
parameter:
csv_data_frame.to_sql(table_name, engine, if_exists='append', chunksize=1000)
来自文档:
失败:如果表存在,什么也不做.
fail: Iftable exists, do nothing.
替换:如果表存在,则将其删除,然后重新创建并插入数据.
replace: If table exists, drop it, recreateit, and insert data.
追加:如果表存在,则插入数据.创建是否不存在.
append: If table exists, insert data. Create ifdoes not exist.
这篇关于使用to_sql将数据附加到pandas中已经存在的表中的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!