Python：如何查询以从 sqlite3 表中提取数据？

Question

I'm trying to get my code to work but I keep getting this error.

File "C:\Users\mikae\Desktop\Sem 9\CSE115\Assignment 2\Actual\A2 (Version 5).py", line 186, in main print_table_bookings(conn,booking_data[i])

IndexError: list index out of range

Currently, this is my code. I'm not done with it, but I'm trying to write out two queries:

1. Find all the bookings of a specific trainer
2. Find the gender of the trainer for a type of training.

I've tried a lot of variations but I just can't get the logic down. I would appreciate feedback and any help that I can get.

Code

import sqlite3
from sqlite3 import Error
import os

# Create a connection to the SQLite database via DB file.
def create_connection(db_file):
    """create a database connection to the SQLite database
    specified by db_file
    :param db_file:database file
    :return:Connection object or None
    """
    
    conn = None
    try:
        conn = sqlite3.connect(db_file)
        return conn
    except Error as e:
        print(e)
    return conn


# Create tables from SQL statement
def create_table(conn,create_table_sql):
    """create a table from the create_table_sql statement
    :param conn:Connection object
    :param create_table_sql:a CREATE TABLE statement
    :return:
    """

    try:
        c = conn.cursor()
        c.execute(create_table_sql)
    except Error as e:
        print(e)
    
# Bookings Table
def print_table_bookings(conn, bookings):
    sql=""" INSERT INTO bookings (booking_id,trainer_id,training_id,session_date,session_slot)
    VALUES (?,?,?,?,?)"""
    c = conn.cursor()
    c.execute(sql,bookings)
    conn.commit()
    return c.lastrowid

# Trainers Table
def print_table_trainers(conn, trainers):
    sql=""" INSERT INTO trainers (trainer_id,name,gender,mobile,specialisation,rate)
    VALUES (?,?,?,?,?,?)"""
    c = conn.cursor()
    c.execute(sql,trainers)
    conn.commit()
    return c.lastrowid

# Trainings Table
def print_table_trainings(conn, trainings):
    sql=""" INSERT INTO trainings (training_id,description,duration)
    VALUES (?,?,?)"""
    c=conn.cursor()
    c.execute(sql,trainings)
    conn.commit()
    return c.lastrowid

# Print Tables
# Print Bookings
def display_bookings(conn):
    c=conn.cursor()
    c.execute("SELECT * FROM bookings")
    rows=c.fetchall()
    for row in rows:
        print(row)
        print("\n") 
        
# Print Bookings
def display_trainers(conn):
    c=conn.cursor()
    c.execute("SELECT * FROM trainers")
    rows=c.fetchall()
    for row in rows:
        print(row)
        print("\n")
        
# Print Bookings
def display_trainings(conn):
    c=conn.cursor()
    c.execute("SELECT * FROM trainings")
    rows=c.fetchall()
    for row in rows:
        print(row)
        print("\n")
        
# Query to display Trainer's bookings by Trainer's Name
# NOT DONE

# Main Code
def main():
    database = os.path.abspath(os.getcwd()) + "\healthhub.db"

    # Create Bookings Table
    sql_create_bookings_table = """CREATE TABLE IF NOT EXISTS bookings (
                                booking_id INTEGER PRIMARY KEY,
                                trainer_id INTEGER NOT NULL,
                                training_id TEXT,
                                session_date INTEGER NOT NULL,
                                session_slot TEXT NOT NULL,
                                FOREIGN KEY(trainer_id) REFERENCES trainer(id),
                                FOREIGN KEY(training_id) REFERENCES training(id)
                                );"""

    # Create Trainer Table
    sql_create_trainers_table = """CREATE TABLE IF NOT EXISTS trainers (
                                trainer_id INTEGER PRIMARY KEY,
                                name TEXT NOT NULL,
                                gender TEXT NOT NULL,
                                mobile TEXT NOT NULL,
                                specialisation TEXT NOT NULL,
                                rate INTEGER NOT NULL
                                );"""

    # Create Trainings Table
    sql_create_trainings_table = """CREATE TABLE IF NOT EXISTS trainings (
                                training_id INTEGER PRIMARY KEY,
                                description TEXT NOT NULL,
                                duration INTEGER NOT NULL
                                );"""

    # Create a Database(DB) Connection
    conn = create_connection(database)

    # Create Tables using def above
    if conn is not None: 
        create_table(conn,sql_create_bookings_table)
        create_table(conn,sql_create_trainers_table)
        create_table(conn,sql_create_trainings_table)

        with conn:
            # Error prevention
            c=conn.cursor()
            c.execute("DELETE FROM bookings;");
            c.execute("DELETE FROM trainers;");
            c.execute("DELETE FROM trainings;");

            # Populating the tables
            # Bookings table
            booking_1 = (101,'001','0001','01082021','Morning')
            booking_2 = (102,'001','0001','01082021','Morning')
            booking_3 = (103,'001','0001','01082021','Morning')
            booking_4 = (104,'001','0001','01082021','Morning')
            booking_5 = (105,'001','0001','01082021','Morning')
            booking_6 = (106,'001','0001','01082021','Morning')
            booking_7 = (107,'001','0001','01082021','Morning')
            booking_8 = (108,'001','0001','01082021','Morning')
            booking_9 = (109,'001','0001','01082021','Morning')
            booking_10 = (110,'001','0001','01082021','Morning')

            # Trainers Table
            trainer_1 = (2021,'Gary','Male','91234567','Weight Loss','85')
            trainer_2 = (2022,'Bary','Male','91234568','Weight Loss','185')
            trainer_3 = (2023,'Mary','Female','91234569','Weight Loss','85')
            trainer_4 = (2024,'Stephanie','Female','91234570','Weight Loss','85')
            trainer_5 = (2025,'Austin','Male','91234571','Weight Loss','65')
            trainer_6 = (2026,'Tynia','Female','91234572','Weight Loss','85')
            trainer_7 = (2027,'Oswald','Male','91234573','Weight Loss','55')
            trainer_8 = (2028,'Aria','Female','91234574','Weight Loss','45')
            trainer_9 = (2029,'Micheal','Male','91234575','Weight Loss','95')
            trainer_10 = (2030,'Lily','Female','91234576','Weight Loss','105')


            #trainings table
            trainings_1 = (3031,'Weight Loss','90')
            trainings_2 = (3032,'Cardio','90')
            trainings_3 = (3033,'Boxing','90')
            trainings_4 = (3034,'Kickboxing','90')
            trainings_5 = (3035,'Muay Thai','90')
            trainings_6 = (3036,'Kettlebells','90')
            trainings_7 = (3037,'Strength training','90')
            trainings_8 = (3038,'Yoga','90')
            trainings_9 = (3039,'Sparring','90')
            trainings_10 = (3040,'Jiu-jitsu','90')

            #Loop to write data into table
            booking_data = [booking_1,booking_2,booking_3,booking_4,booking_5,booking_6,booking_7,booking_8,booking_9,booking_10]
            trainer_data = [trainer_1,trainer_2,trainer_3,trainer_4,trainer_5,trainer_6,trainer_7,trainer_8,trainer_9,trainer_10]
            training_data =  [trainings_1,trainings_2,trainings_3,trainings_4,trainings_5,trainings_6,trainings_7,trainings_8,trainings_9,trainings_10]
            i=0
            while i < 20:
                print_table_bookings(conn,booking_data[i])
                print_table_trainers(conn,trainer_data[i])
                print_table_trainings(conn,training_data[i])
                i=i+1 
            
            
            #Displaying Table
            print_table_bookings(conn)
            print()
            print_table_trainers(conn)
            print()
            print_table_trainings(conn)
            print()
                
            
if __name__=='__main__':
    main()

Answer 1

here:

booking_1 = (101,'001','0001','01082021','Morning')

...

booking_data = [booking_1,booking_2,booking_3,booking_4,booking_5,booking_6,booking_7,booking_8,booking_9,booking_10]

...

create_table(conn,booking_data[i])

the booking_data[i] will never be a string containing a SQL instruction. Here you probably want to transform this tuple into a INSERT statement before you execute it.

Answer 2

In main() after you create the tables, you are trying to insert new rows with this loop:

i=0
while i < 20:
    create_table(conn,booking_data[i])
    create_table(conn,trainer_data[i])
    create_table(conn,training_data[i])
    i=i+1 

in which you use create_table() instead of print_table_bookings() , print_table_trainers() and print_table_trainings() .

Change to this:

i=0
while i < 20:
    print_table_bookings(conn,booking_data[i])
    print_table_trainers(conn,trainer_data[i])
    print_table_trainings(conn,training_data[i])
    i=i+1