Python Connecting With Database (PDF)

Connecting With Database using Python
Verifying the MySQL dB Interface Installation : To access the MySQL database from Python, database driver needed. MySQL Connector/Python is a standardized database driver provided by MySQL. MySQL Connector/Python supports almost all features provided...

Connecting With Database using Python
Verifying the MySQL dB Interface Installation : To access the MySQL database from Python, database driver needed. MySQL Connector/Python is a standardized database driver provided by MySQL. MySQL Connector/Python supports almost all features provided by MySQL. It allows to convert the parameter’s value between Python and MySQL data types e.g., Python datetime and MySQL DATETIME. MySQL Connector/Python is designed specifically to MySQL. It supports all MySQL extensions such as LIMIT clause. MySQL Connector/Python allows to compress the data stream between Python and MySQL database server using protocol compression. It supports connections using TCP/IP socket and secure TCP/IP connection using SSL. MySQL Connector/Python is an API implemented using pure Python. It means that we don’t need to install any MySQL client library or any Python modules except the standard library.  Prerequisites : Before installing MySQL Connector/Python, We need:  Root or Administrator privileges in order to perform the installation.  Python installed on system (Note that the MySQL Connector/Python installation requires python to be in the system’s PATH or it will fail.)  Installation : The pip command, allows to install MySQL Python connector on any OS. Run this Command on Command Prompt: pip install mysql-connector-python  Verifying MySQL Connector/Python installation : After installing the MySQL Python connector, you need to test it to make sure that it is working correctly and you are able to connect to the MySQL database server without any issues. To verify the installation, you use the following steps:  Open Python command line  Type the following code : >>> import mysql.connector >>> mysql.connector.connect(host='localhost', database='mysql', user='root',password='your pass')  If It has been successfully installed the MySQL Connector/Python on system, Following Code will be displayed. Python Notes By : Hiral Pandya Page : 1 of 18 
Working with MySQL Database :  Syntax To Create Database in MySQL : CREATE DATABASE databasename  Syntax To Create Table in MySQL Database : CREATE TABLE table_name (column1 datatype, column2 datatype, column3 datatype,....);  Syntax To Create Table Using Another Table in MySQL Database : CREATE TABLE new_table_name AS SELECT column1, column2,... FROM existing_table WHERE....;
Using MySQL from Python : Steps To Follow In Python To Work With MySQL :  Connect to the database.  Create an object for your database.  Execute the SQL query.  Fetch records from the result.  Informing the Database if we make any changes in the table.
MySQL Cursor :  The MySQL Cursor of mysql-connector-python (and similar libraries) is used to execute statements to communicate with the MySQL database.  Using the methods of it we can execute SQL statements, fetch data from the result sets, call procedures.  We can create Cursor object using the cursor() method of the Connection object/class. Methods of MySQL Cursor Methods Description This method is used to call existing procedures MySQL callproc() database. Close() This method is used to close the current cursor object. Info() This method gives information about the last query. Python Notes By : Hiral Pandya Page : 2 of 18  This method accepts a list series of parameters list. executemany() Prepares an MySQL query and executes it with all the parameters. This method accepts a MySQL query as a parameter execute() and executes the given query. This method retrieves all the rows in the result set of a query and returns them as list of tuples. (If we execute fetchall() this after retrieving few rows it returns the remaining ones) This method fetches the next row in the result of a fetchone() query and returns it as a tuple. This method is similar to the fetchone() but, it retrieves fetchmany() the next set of rows in the result set of a query, instead of a single row This method returns the warnings generated by the last fetchwarnings() executed query. Properties of MySQL Cursor Properties Description This is a read only property which returns the list column_names containing the column names of a result-set. This is a read only property which returns the list description containing the description of columns in a result-set. This is a read only property, if there are any auto- incremented columns in the table, this returns the lastrowid value generated for that column in the last INSERT or, UPDATE operation. This returns the number of rows returned/updated in rowcount case of SELECT and UPDATE operations statement This property returns the last executed statement. Python Notes By : Hiral Pandya Page : 3 of 18 
Create Database In MySQL Using Python : To create a database in MySQL, use the "CREATE DATABASE" statement. import mysql.connector mydb = mysql.connector.connect( host="localhost", user="yourusername", # If Any Password is Set For MySQL password="yourpassword" ) mycursor = mydb.cursor() mycursor.execute("CREATE DATABASE mydatabase")
Create Table In MySQL Database Using Python : To create a database in MySQL, use the "CREATE TABLE" statement. import mysql.connector mydb = mysql.connector.connect( host="localhost", user="yourusername", # If Any Password is Set For MySQL password="yourpassword", database="mydatabase" ) mycursor = mydb.cursor() mycursor.execute "CREATE TABLE TableName (FieldName DataType(Value), FieldName DataType(Value),.....)") Python Notes By : Hiral Pandya Page : 4 of 18  Example: Create DataBase and Create Table import mysql.connector print("DataBase Is Creating") mydb = mysql.connector.connect (host="localhost",user="root") mycursor = mydb.cursor() mycursor.execute("CREATE DATABASE db_StudInfo") mycursor.close() print("DataBase Created Successfully..") print("-"*40) print("Table Is Creating") mydb = mysql.connector.connect (host="localhost",user="root",database="db_StudInfo") str = """CREATE TABLE tbl_StudPerInfoMaster ( Stud_ID int(3) NOT NULL, Stud_Name varchar(250) NOT NULL, Stud_Address varchar(500) NOT NULL, Stud_City varchar(100) NOT NULL, Stud_ContNo varchar(15) NOT NULL, Stud_EmailID varchar(50) NOT NULL, Stud_Remarks varchar(150) NOT NULL )""" mycursor = mydb.cursor() mycursor.execute(str) mycursor.close() print("Table Created Successfully..") print("-"*40) Python Notes By : Hiral Pandya Page : 5 of 18  Example: Insert Record In Table import mysql.connector mydb = mysql.connector.connect (host="localhost",user="root",database="db_StudInfo") mycursor = mydb.cursor() qry = """INSERT INTO tbl_StudPerInfoMaster (Stud_ID, Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) VALUES (1, 'Mr. AAA', 'Address of AAA', 'Jamnagar', '9874563210', '[email protected]', 'No Remarks')""" mycursor.execute(qry) mydb.commit() print("-"*40) print(mycursor.rowcount," Record Inserted") mycursor.close() print("-"*40) OutPut: Python Notes By : Hiral Pandya Page : 6 of 18 Example: Insert Record With Single Parameter Using execute() Method import mysql.connector mydb = mysql.connector.connect (host="localhost",user="root",database="db_StudInfo") mycursor = mydb.cursor() qry = """INSERT INTO tbl_StudPerInfoMaster (Stud_ID, Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) VALUES(%s, %s, %s, %s, %s, %s, %s)""" val= (1, 'Mr. AAA', 'Address of AAA', 'Jamnagar', '9874563210', '[email protected]', 'No Remarks') mycursor.execute(qry,val) mydb.commit() print("-"*40) print(mycursor.rowcount," Record Inserted") mycursor.close() print("-"*40) OutPut: Python Notes By : Hiral Pandya Page : 7 of 18  Example: Insert Record Using executemany() Method import mysql.connector mydb = mysql.connector.connect (host="localhost",user="root",database="db_StudInfo") mycursor = mydb.cursor() qry = """INSERT INTO tbl_StudPerInfoMaster (Stud_ID, Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) VALUES(%s, %s, %s, %s, %s, %s, %s)""" param = [(2, 'Mr. BBB', 'Address of BBB', 'BARODA', '8523697410', '[email protected]', 'No Remarks'), (3, 'Mr. CCC', 'Address of CCC', 'RAJKOT', '3698521470', '[email protected]', 'No Remarks'), (4, 'Mr. DDD', 'Address of DDD', 'SURAT', '8794563210', '[email protected]', 'No Remarks'), (5, 'Mr. DDD', 'Address of EE', 'Jamnagar', '7987456312', '[email protected]', 'No Remarks')] mycursor.executemany(qry,param) mydb.commit() print("-"*40) print(mycursor.rowcount," Record Inserted") mycursor.close() print("-"*40) OutPut: Python Notes By : Hiral Pandya Page : 8 of 18  Example: Insert Record Using PYTHON GUI from tkinter import * import tkinter as tk from tkinter import messagebox import tkinter.font as font import mysql.connector def AddRecords(): Stud_ID = txtID.get() Stud_Name = txtName.get() Stud_Address = txtAdd.get("0.0",END) Stud_City = txtCity.get() Stud_ContNo = txtContNo.get() Stud_EmailID = txtEmailID.get() Stud_Remarks = txtRem.get() mysqldb=mysql.connector.connect(host="localhost",user ="root",database="db_StudInfo") mycursor=mysqldb.cursor() try: sql = """INSERT INTO tbl_StudPerInfoMaster (Stud_ID, Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) VALUES(%s, %s, %s, %s, %s, %s, %s)""" val = (Stud_ID, Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) mycursor.execute(sql, val) mysqldb.commit() messagebox.showinfo("Data Insert", "Record inserted successfully...") except Exception as e: messagebox.showinfo("Exception ", str(e)) mysqldb.rollback() mysqldb.close() root = Tk() root.title("Student Information") root.geometry("500x500") global Stud_ID global Stud_Name global Stud_Address Python Notes By : Hiral Pandya Page : 9 of 18 global Stud_City global Stud_ContNo global Stud_EmailID global Stud_Remarks myfont = font.Font(family='Verdana',size=12,weight="normal") Label(root, text="ID :",font='myfont').grid( column=0, row=0, padx=110, pady=10) txtID = Entry(root,font='myfont',bd=1,relief='solid',width=5) txtID.place(x=140, y=10) Label(root, text="Name :",font='myfont').place(x=84, y=40) txtName = Entry(root,font='myfont',bd=1,relief='solid') txtName.place(x=140, y=40) Label(root, text="Address :",font='myfont').place(x=66, y=70) txtAdd = Text(root,font='myfont',bd=1,relief='solid',height = 2.5, width = 20) txtAdd.place(x=140, y=70) Label(root, text="City :",font='myfont').place(x=96, y=135) txtCity = Entry(root,font='myfont',bd=1,relief='solid') txtCity.place(x=140, y=135) Label(root, text="Contact No :",font='myfont').place(x=48, y=165) txtContNo = Entry(root,font='myfont',bd=1,relief='solid') txtContNo.place(x=140, y=165) Label(root, text="Email ID :",font='myfont').place(x=66, y=195) txtEmailID = Entry(root,font='myfont',bd=1,relief='solid') Python Notes By : Hiral Pandya Page : 10 of 18 txtEmailID.place(x=140, y=195) Label(root, text="Remarks :",font='myfont').place(x=60, y=225) txtRem = Entry(root,font='myfont',bd=1,relief='solid') txtRem.place(x=140, y=225) Button(root, text="Add", command=AddRecords,bg='Navy',fg='White',font='myfont' , width=15, height=2).place(x=140, y=270) root.mainloop() Example: Display Records Using PYTHON GUI from tkinter import * import tkinter as tk from tkinter import messagebox import tkinter.font as font import mysql.connector root = Tk() root.title("Student Information") root.geometry("700x400") frameButton = Frame(root) frameButton.pack(fill=tk.X,side = TOP ) frameData = Frame(root,pady=20) frameData.pack(side = TOP ) myfont = font.Font(family='Verdana',size=12,weight="normal") def displayRecords(): try: mysqldb=mysql.connector.connect(host="localhost",user ="root",database="db_StudInfo") my_cursor=mysqldb.cursor() my_cursor.execute("SELECT * FROM tbl_studperinfomaster") global i i=0 Python Notes By : Hiral Pandya Page : 11 of 18  for student in my_cursor: for j in range(len(student)): e = Label(frameData,width=12,bg='tan',height=3, text=my_cursor.column_names[j], relief='solid',bd=1) e.configure(font=font.Font(family='calibri',size=10,w eight="normal")) e.grid(row=i, column=j) k = j e = Label(frameData,width=10,bg='tan',height=3, text="Edit",relief='solid',bd=1) e.configure(font=font.Font(family='calibri',size=10,w eight="normal")) e.grid(row=0, column=k+2) my_cursor.execute("SELECT * FROM tbl_studperinfomaster") i = 1 for student in my_cursor: for j in range(len(student)): e = Label(frameData,width=12,height=3, text=student[j], relief='solid',bd=1,wraplength=80) e.configure(font=font.Font(family='calibri',size=10,w eight="normal")) e.grid(row=i, column=j) e = tk.Button(frameData,width=7,height=2,fg='yellow',bg=' Green', text='Edit',relief='solid', font='myfont',bd=1,command=lambda k=student:edit_data(k)) e.grid(row=i, column=len(student) + 1) i=i+1 except Exception as e: print(e) mysqldb.rollback() Python Notes By : Hiral Pandya Page : 12 of 18  mysqldb.close() Button(frameButton, text="Display", command=displayRecords,bg='tan',fg='Navy',font='myfon t', height=1).pack(fill=tk.X) root.mainloop() Example: Edit / Update / Delete Records Using PYTHON GUI from tkinter import * import tkinter as tk from tkinter import messagebox import tkinter.font as font import mysql.connector root = Tk() root.title("Student Information") root.geometry("780x400") frameButton = Frame(root) frameButton.pack(fill=tk.X,side = TOP ) frameData = Frame(root,pady=20) frameData.pack(side = TOP ) frameDataEdit = Frame(root,pady=20) frameDataEdit.pack(side = TOP ) myfont = font.Font(family='Verdana',size=12,weight="normal") global mydb global Stud_Name global Stud_Address global Stud_City global Stud_ContNo global Stud_EmailID global Stud_Remarks global i def displayRecords(): try: frameDataEdit.pack_forget() frameData.pack(side = TOP) mydb = mysql.connector.connect(host="localhost",user="root", Python Notes By : Hiral Pandya Page : 13 of 18 database="db_StudInfo") my_cursor = mydb.cursor() my_cursor.execute("SELECT * FROM tbl_studperinfomaster ORDER BY Stud_ID") i=0 for student in my_cursor: for j in range(len(student)): e = Label(frameData,width=12,bg='tan',height=3, text=my_cursor.column_names[j], relief='solid',bd=1) e.configure(font=font.Font(family='calibri',size=10,w eight="normal")) e.grid(row=i, column=j) k = j e = Label(frameData,width=10,bg='tan',height=3, text="Edit",relief='solid',bd=1) e.configure(font=font.Font(family='calibri',size=10,w eight="normal")) e.grid(row=0, column=k+2) e = Label(frameData,width=10,bg='RED',fg='white',height=3 , text="Delete",relief='solid',bd=1) e.configure(font=font.Font(family='calibri',size=10,w eight="bold")) e.grid(row=0, column=k+3) my_cursor.execute("SELECT * FROM tbl_studperinfomaster") i = 1 for student in my_cursor: for j in range(len(student)): e = Label(frameData,width=12,height=3, text=student[j], relief='solid',bd=1,wraplength=80) e.configure(font=font.Font(family='calibri',size=10,w Python Notes By : Hiral Pandya Page : 14 of 18 eight="normal")) e.grid(row=i, column=j) e = tk.Button(frameData,width=7,height=2,fg='yellow',bg=' Green', text='Edit',relief='solid', font='myfont',bd=1,command=lambda k=student:edit_data(k)) e.grid(row=i, column=len(student) + 1) e = tk.Button(frameData,width=7,height=2,fg='yellow',bg=' RED', text='Delete',relief='solid', font='myfont',bd=1,command=lambda k=student:Delete_data(k)) e.grid(row=i, column=len(student) + 2) i=i+1 my_cursor.close() except Exception as e: print(e) mydb.rollback() mydb.close() def Delete_data(r): mydb = mysql.connector.connect(host="localhost",user="root", database="db_StudInfo") my_cursor = mydb.cursor() my_cursor.execute("DELETE FROM tbl_StudperInfoMaster WHERE Stud_ID = "+ str(r)) my_cursor.close() mydb.commit() displayRecords() def edit_data(r): frameData.pack_forget() frameDataEdit.pack(side = TOP) mydb = mysql.connector.connect(host="localhost",user="root", database="db_StudInfo") my_cursor = mydb.cursor() Python Notes By : Hiral Pandya Page : 15 of 18  my_cursor.execute("SELECT * FROM tbl_studperinfomaster WHERE Stud_ID = "+ str(r)) s = my_cursor.fetchone() strName = StringVar(frameDataEdit) strName.set(s) strCity = StringVar(frameDataEdit) strCity.set(s) strContNo = StringVar(frameDataEdit) strContNo.set(s) strEmailID = StringVar(frameDataEdit) strEmailID.set(s) Label(frameDataEdit, text="Name : ",font='myfont',width=10,justify='right',anchor='e'). grid(column=0, row=1) txtName = Entry(frameDataEdit,textvariable=strName,font='myfont ',width=30,bd=1,relief='solid') txtName.grid(column=1, row=1,sticky='W') Label(frameDataEdit, text="Address : ",font='myfont',width=10,anchor='e').grid(column=0, row=2,pady=0) txtAdd = Text(frameDataEdit,font='myfont',bd=1,relief='solid', height = 2.5, width = 30) txtAdd.insert(1.0,s) txtAdd.grid(column=1, row=2,pady=5,sticky=W) Label(frameDataEdit, text="City : ",font='myfont',width=10,anchor='e').grid(column=0, row=3) txtCity = Entry(frameDataEdit,textvariable=strCity,font='myfont ',width=30,bd=1,relief='solid') txtCity.grid(column=1, row=3,pady=5,sticky=W) Label(frameDataEdit, text="Contact No : ",font='myfont',width=10,anchor='e').grid(column=0, row=4) txtContNo = Entry(frameDataEdit,textvariable=strContNo,font='myfo Python Notes By : Hiral Pandya Page : 16 of 18 nt',width=30,bd=1,relief='solid') txtContNo.grid(column=1, row=4,pady=5,sticky=W) Label(frameDataEdit, text="Email ID : ",font='myfont',width=10,anchor='e').grid(column=0, row=5) txtEmailID = Entry(frameDataEdit,textvariable=strEmailID,font='myf ont',width=30,bd=1,relief='solid') txtEmailID.grid(column=1, row=5,pady=5,sticky=W) Label(frameDataEdit, text="Remarks : ",font='myfont',width=10,anchor='e').grid(column=0, row=6,pady=0) txtRem = Text(frameDataEdit,font='myfont',bd=1,relief='solid', height = 2.5, width = 30) txtRem.insert(1.0,s) txtRem.grid(column=1, row=6,pady=5,sticky=W) def UpdateData(r): Stud_Name = txtName.get() Stud_Address = txtAdd.get("0.0",END) Stud_City = txtCity.get() Stud_ContNo = txtContNo.get() Stud_EmailID = txtEmailID.get() Stud_Remarks = txtRem.get("0.0",END) mydb = mysql.connector.connect(host="localhost",user="root", database="db_StudInfo") my_cursor = mydb.cursor() QRY = """UPDATE tbl_studperinfomaster SET Stud_Name = %s,Stud_Address = %s, Stud_City = %s, Stud_ContNo = %s, Stud_EmailID = %s, Stud_Remarks = %s WHERE Stud_ID = """ val = (Stud_Name, Stud_Address, Stud_City, Stud_ContNo, Stud_EmailID, Stud_Remarks) my_cursor.execute(QRY+ str(r),val) my_cursor.close() frameDataEdit.pack_forget() frameData.pack(side = TOP) Python Notes By : Hiral Pandya Page : 17 of 18  displayRecords() def CancelData(): displayRecords() Button(frameDataEdit, text="Update", command=lambda :UpdateData(r),bg='darkOrange',fg='Navy',font='myfont ', width=15, height=2,justify='center').grid(column=1, row=7,padx=0,pady=10) Button(frameDataEdit, text="Cancel", command=CancelData,bg='Green',fg='White',font='myfont ', width=8, height=2).grid(column=0, row=7,pady=10) Button(frameButton, text="Display", command=displayRecords,bg='tan',fg='Navy',font='myfon t', height=1).pack(fill=tk.X) root.mainloop() Python Notes By : Hiral Pandya Page : 18 of 18