通过Python将数据从csv插入postgreSQL数据库
我对postgreSQL或SQL是全新的。 我试图通过Python在数据库中创建一个表，然后将数据从.csv文件加载到表中。 我的代码如下所示：通过Python将数据从csv插入postgreSQL数据库,python,sql,database,postgresql,csv,Python,Sql,Database,Postgresql,Csv,我对postgreSQL或SQL是全新的。 我试图通过Python在数据库中创建一个表，然后将数据从.csv文件加载到表中。 我的代码如下所示： import csv import psycopg2 #Establish connection to database con = psycopg2.connect( host = "localhost", database = "kundeavgang", user = "postgres",
import csv
import psycopg2
#Establish connection to database
con = psycopg2.connect(
host = "localhost",
database = "kundeavgang",
user = "postgres",
password = "postgres",
)
#Cursor
cur = con.cursor()
#If a mistake is made, start from scratch
cur.execute("DROP TABLE IF EXISTS kundeavgang")
#Create table
cur.execute('''
CREATE TABLE "kundeavgang"(
"customerID" TEXT,
"gender" TEXT,
"SeniorCitizen" TEXT,
"Partner" TEXT,
"Dependents" TEXT,
"tenure" INT,
"PhoneService" TEXT,
"MultipleLines" TEXT,
"InternetService" TEXT,
"OnlineSecurity" TEXT,
"DeviceProtection" TEXT,
"TechSupport" TEXT,
"StreamingMovies" TEXT,
"Contract" TEXT,
"PaperlessBilling" TEXT,
"PaymentMethod" TEXT,
"MonthlyCharges" FLOAT,
"TotalCharges" FLOAT,
"Churn" TEXT
)
''')
#Acsess .csv file
with open('kundeavgang.csv') as csvFile:
reader = csv.reader(csvFile)
skipHeader = next(reader) #Account for header
for row in reader:
customerID = row[0]
gender = row[1]
SeniorCitizen = row[2]
Partner = row[3]
Dependents = row[4]
tenure = row[5]
PhoneService = row[6]
MultipleLines = row[7]
InternetService = row[8]
OnlineSecurity = row[9]
OnlineBackup = row[10]
DeviceProtection = row[11]
TechSupport = row[12]
StreamingTV = [13]
StreamingMovies = row[14]
Contract = row[15]
PaperlessBilling = row[16]
PaymentMethod = row[17]
MonthlyCharges = row[18]
TotalCharges = row[19]
Churn = row[20]
cur.execute('''INSERT INTO kundeavgang(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn)
VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)''',(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn))
#Commit the transaction
con.commit()
#End connection
con.close()
cur.execute('''INSERT INTO kundeavgang(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn)
VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)''',(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn))
VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)''',(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn))
所有帮助或解释将不胜感激
%s(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn)
insert语句将要插入20列的问题是，您在元组中提供了20个值，但有22个占位符（
%s%s(customerID,gender,SeniorCitizen,Partner,Dependents,tenure,PhoneService,MultipleLines,InternetService,OnlineSecurity,OnlineBackup,DeviceProtection,TechSupport,StreamingTV,StreamingMovies,Contract,PaperlessBilling,PaymentMethod,TotalCharges,Churn)
插入语句要插入到20列中的问题，在元组中提供20个值，但您有22个占位符（<代码> %s>代码>）.< /p> 从文本文件中插入大容量插入，考虑或<代码> PysCopg2。此外，请确保提交您的执行：
cur.execute("DROP TABLE IF EXISTS kundeavgang")
con.commit()
cur.execute('''CREATE TABLE "kundeavgang" ... ''')
con.commit()
with open('kundeavgang.csv') as csvFile:
next(csvFile) # SKIP HEADERS
cur.copy_from(csvFile, "kundeavgang", sep=",")
# POSTGRES COPY COMMAND FOR CSV MODE
# cur.copy_expert("""COPY "kundeavgang" FROM STDIN WITH CSV""", csvFile)
con.commit()
<>文本文件中的大容量插入，考虑或<代码> PycPGG2<代码>。此外，请确保提交您的执行：
cur.execute("DROP TABLE IF EXISTS kundeavgang")
con.commit()
cur.execute('''CREATE TABLE "kundeavgang" ... ''')
con.commit()
with open('kundeavgang.csv') as csvFile:
next(csvFile) # SKIP HEADERS
cur.copy_from(csvFile, "kundeavgang", sep=",")
# POSTGRES COPY COMMAND FOR CSV MODE
# cur.copy_expert("""COPY "kundeavgang" FROM STDIN WITH CSV""", csvFile)
con.commit()
问题是要填充的列数与提供的列表长度不匹配。这是处理大量列时容易犯的错误。减少错误风险的一种方法是使用列或值列表的长度来构建语句
cols = [name1, name2,...]
vals = [val1, val2, ...]
assert len(cols) == len(vals), 'mismatch between number of columns and number of values'
template = """INSERT INTO tbl ({}) VALUES ({})"""
stmt = template.format(', '.join(cols), ','.join(['%s'] * len(vals)))
cur.execute(stmt, vals)
请注意，动态构建列名时，最好引用它们-psycopg2提供了这一点。问题是要填充的列数与提供的列表长度不匹配。这是处理大量列时容易犯的错误。减少错误风险的一种方法是使用列或值列表的长度来构建语句
cols = [name1, name2,...]
vals = [val1, val2, ...]
assert len(cols) == len(vals), 'mismatch between number of columns and number of values'
template = """INSERT INTO tbl ({}) VALUES ({})"""
stmt = template.format(', '.join(cols), ','.join(['%s'] * len(vals)))
cur.execute(stmt, vals)
请注意，在动态构建列名时，最好引用它们-psycopg2提供了这一点。@snakecharmerb您能详细说明这意味着什么吗？或者我如何将我想要的实际数据输入SQL而不是22%s？为什么不使用并绕过将数据读入Python？您的
行行%s%s