我采用了上面aws_学徒建议的方法，即首先创建表，然后将数据写入表中。在
下面的代码首先从df(自动定义表名和数据类型)自动生成一个mysql表，然后将df数据写入该表。在
我不得不克服一些小问题，比如：未命名的csv列，确定mysql表中每个字段的正确数据类型。在
我肯定还有很多其他的(更好的？)方法，但这似乎有效。在import pandas as pd
from sqlalchemy import create_engine
infile = r'path/to/file.csv'
db = 'a001_db'
db_tbl_name = 'a001_rd004_db004'
'''
Load a csv file into a dataframe; if csv does not have headers, use the headers arg to create a list of headers; rename unnamed columns to conform to mysql column requirements
'''
def csv_to_df(infile, headers = []):
if len(headers) == 0:
df = pd.read_csv(infile)
else:
df = pd.read_csv(infile, header = None)
df.columns = headers
for r in range(10):
try:
df.rename( columns={'Unnamed: {0}'.format(r):'Unnamed{0}'.format(r)}, inplace=True )
except:
pass
return df
'''
Create a mapping of df dtypes to mysql data types (not perfect, but close enough)
'''
def dtype_mapping():
return {'object' : 'TEXT',
'int64' : 'INT',
'float64' : 'FLOAT',
'datetime64' : 'DATETIME',
'bool' : 'TINYINT',
'category' : 'TEXT',
'timedelta[ns]' : 'TEXT'}
'''
Create a sqlalchemy engine
'''
def mysql_engine(user = 'root', password = 'abc', host = '127.0.0.1', port = '3306', database = 'a001_db'):
engine = create_engine("mysql://{0}:{1}@{2}:{3}/{4}?charset=utf8".format(user, password, host, port, database))
return engine
'''
Create a mysql connection from sqlalchemy engine
'''
def mysql_conn(engine):
conn = engine.raw_connection()
return conn
'''
Create sql input for table names and types
'''
def gen_tbl_cols_sql(df):
dmap = dtype_mapping()
sql = "pi_db_uid INT AUTO_INCREMENT PRIMARY KEY"
df1 = df.rename(columns = {"" : "nocolname"})
hdrs = df1.dtypes.index
hdrs_list = [(hdr, str(df1[hdr].dtype)) for hdr in hdrs]
for i, hl in enumerate(hdrs_list):
sql += " ,{0} {1}".format(hl[0], dmap[hl[1]])
return sql
'''
Create a mysql table from a df
'''
def create_mysql_tbl_schema(df, conn, db, tbl_name):
tbl_cols_sql = gen_tbl_cols_sql(df)
sql = "USE {0}; CREATE TABLE {1} ({2})".format(db, tbl_name, tbl_cols_sql)
cur = conn.cursor()
cur.execute(sql)
cur.close()
mit()
'''
Write df data to newly create mysql table
'''
def df_to_mysql(df, engine, tbl_name):
df.to_sql(tbl_name, engine, if_exists='replace')
df = csv_to_df(infile)
create_mysql_tbl_schema(df, mysql_conn(mysql_engine()), db, db_tbl_name)
df_to_mysql(df, mysql_engine(), db_tbl_name)
