Delete the table "customers" if it exists: import mysql.connectormydb = mysql.connector.connect( host="localhost", user="yourusername", password="yourpassword", database="mydatabase") mycursor = mydb.cursor()sql = "DROP TABLE IF EXISTS customers"mycursor.execute(sql) Run example » ...
5'''6Created on2019-5-227@author:北京-宏哥8Project:学习和使用python操作MySQL数据库9'''10#3.导入模块11importpymysql1213importpymysql1415# 打开数据库连接16conn=pymysql.connect('localhost','root','root','testdb')1718#使用cursor()方法创建一个游标对象cursor19cursor=conn.cursor()# 游标对象用于...
# 创建存储数据的表 table_name = 'public.excel_data' ddl = """ DROP TABLE IF EXISTS public.excel_data; CREATE TABLE IF NOT EXISTS public.excel_data ( file_nm VARCHAR(255), cust_nm VARCHAR(255), cert_no VARCHAR(255), prod_nm VARCHAR(255), amt numeric(20,2), crt_dtm timestamp ...
DROP TABLE employee; 1. 删除不存在的表会报错。若指定 IF EXISTS 关键字,删除不存在的表,不会报错,如: AI检测代码解析 DROP TABLE IF EXISTS employee; 1. 如果要删除的表被其他表引用,即其他表的外键引用了表的任何主键或唯一键,则需要在 DROP TABLE 语句中包含 CASCADE 选项,如: AI检测代码解析 DROP T...
iterations为迭代计算的次数 def calculatepagerank(self, iterations=20): # 清除您当前的pagerank表 self.curs.execute('drop table if exists pagerank') self.curs.execute('create table pagerank(urlid primary key,score)') # 初始化每个url,令其pagerank的值为1 for (urlid,) in self.curs.execute(...
-- Create an input table with some example values.DROPTABLEIFEXISTSvalues_table;CREATETABLEvalues_table (aSTRING, bINT);INSERTINTOvalues_tableVALUES('abc',2), ('abc',4), ('def',6), ('def',8)"; SELECT * FROM values_table;
DROPPROCEDUREIFEXISTSPyTrainTestSplit; GOCREATEPROCEDURE[dbo].[PyTrainTestSplit] (@pctint)ASDROPTABLEIFEXISTSdbo.nyctaxi_sample_trainingSELECT*intonyctaxi_sample_trainingFROMnyctaxi_sampleWHERE(ABS(CAST(BINARY_CHECKSUM(medallion,hack_license)asint)) %100) < @pctDROPTABLEIFEXISTSdbo.nyctaxi_sample...
stmt ="SHOW TABLES LIKE '"+name+"'"mycursor.execute(stmt)returnmycursor.fetchone()# 删除一个表(无论它是否已经存在)defdropTable(mycursor, name): stmt ="DROP TABLE IF EXISTS "+name mycursor.execute(stmt)# buffered=True 不设的话,查询结果没有读完会报错# raise errors.InternalError("Unread...
file.write("drop table if exists dm_%s;\r\n" % tableName_list[i][0].lower()) file.write("create table dm_%s(dm varchar(200) comment '代码', mc varchar(200) comment '名称') comment='%s';\r\n"\ % (tableName_list[i][0].lower(), tableName_list[i][1])) else: print("...
DROP TABLE IF EXISTS [dbo].[py_rental_predictions]; GO CREATE TABLE [dbo].[py_rental_predictions]( [RentalCount_Predicted] [int] NULL, [RentalCount_Actual] [int] NULL, [Month] [int] NULL, [Day] [int] NULL, [WeekDay] [int] NULL, [Snow] [int] NULL, [Holiday] [int] ...