How to use column values from sql database as parameters of python function?

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I am trying to check weather the years in one of the column of my table movie is a leap year or not. If yes i want to the name of the movie corresponding to it.

I have tried the following code

def leap_year(year):
    if year%4==0:
        if(year%100==0):
            if(year%400==0):
                return True
            else:
                return False
        else:
            return True           
    else:
        return False

result=pd.read_sql_query("select m.name from movie m where m.year = {}".format(leap_year(m.year)),conn)

print(result)

I know it does not work as i can't directly pass m.year, but i tried to find but could not get the right syntax to do this.

Use calendar

import calendar

def leapyear(year):
    result = calendar.isleap(year)
    if result == True:
        print(str(year) + ' is a leap year')
    else:
        print(str(year) + ' is not a leap year')

leapyear(2018)

use your sql column's year as the year input for the function

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I don't quite understand what you're trying to do with your code... But here, this is the best I could think up

import sqlite3

def leap_year(year):
    if year%4==0:
        if(year%100==0):
            if(year%400==0):
                return True
            else:
                return False
        else:
            return True;

    else:
        return False

with sqlite3.connect("db.db") as conn:
    cur = conn.cursor()
    cur.execute("SELECT m.year FROM movie WHERE m.year = ?", (leap_year(m.year)))
    results = cur.fetchall()
    for result in results:
        print(result)

A Simple Approach To Templated SQL Queries In Python, Here, the values were replaced by placeholders with python variable For a data scientist, it may be natural to get results of the query in a Pandas data frame. Apply a JinjaSql template (string) substituting parameters (dict) and return The function takes the table name, the column name and the default� Note that the parameters are passed as a tuple. The database API does proper escaping and quoting of variables. Be careful not to use the string formatting operator (%), because. it does not do any escaping or quoting. it is prone to Uncontrolled string format attacks e.g. SQL injection.

First select all of the years and movie names from your table. The way you have it set up now is filtering it to a single year which isn't what it sounds like you want.

results = pd.read_sql_query("select name, year from movies", con=conn)

Now go through each year in the results and run the leap year function over it.

import calendar

for index, row in results.iterrows():
    if calendar.isleap(row['year']):
        print(row['name'])

Python MySQL Execute Parameterized Query using Prepared , Use Python variable by replacing the placeholder in the For this article, we are going to use the Employee table present in my MySQL server. see it's column details. or prepared statement for sending SQL queries to the database. This function accepts the required parameters: Host, Database, User,� Pandas read_sql_query() is an inbuilt function that read SQL query into a DataFrame. The read_sql_query() function returns a DataFrame corresponding to the result set of the query string. Optionally provide an index_col parameter to use one of the columns as the index; otherwise, the default integer index will be used.

Applying Functions to Columns, Applying a Function to a Column We have seen many examples of creating new columns of For example, it might take just one number as its argument, as in the function In our earlier examples using Census data, we saw that the variable AGE had a In Python, every function, including cut_off_at_100 , is also a value. With the helper functions above, creating and running templated SQL queries in python is very easy. Because the details of parameter substitution are hidden, one can focus on building the template and the set of parameters and then call a single function to get the final SQL. One important caveat is the risk of code injection.

Learn SQL: User-Defined Functions, The data model we'll use to explain user-defined functions Takes parameters as input; Does something with these input values (SQL The important thing to notice here is that we've used function as a “column” in our select query. JSON (13); PowerShell (65); Python (24); R (9); SQL commands (161)� read_sql: This function has two parameters SQL connection and SQL Query used to fire commands on the database. A read_sql function extracts data from SQL tables and assigns it to Pandas Dataframe object; Inserting data from Python Pandas Dataframe to SQL Server database. Once we have the computed or processed data in Python, there would be a

SQL Lag function overview and examples, In the article SQL Server Lead function overview and examples, we We use a Lag() function to access previous rows data as per defined offset value. It is a mandatory argument, and we cannot execute the lag function without this The first row shows NULL value for the EndDate column because it� The end goal is to insert new values into the dbo.Person table using Python.. Once you have your data ready, proceed to the next step. Step 2: Establish a connection between Python and SQL Server

Comments
  • What is your table format? What are the columns? Your first step should be to write a static query that works. Then turn that query to python. You probably want to do something like: ...where m.year = \'{}\'".format(leap_year)... though m.year does not sound valid.
  • i'm confused. you're trying to select the year from the database where the year is equal to the year?
  • so movie table has following columns : name , year . I want to retrieve the year value from the column and use it in my function leap_year and check if its leap or not. if its leap i want to print the name of the movie corresponding to that year. ofcourse there are many movies in one year
  • You can adjust the values, considering it made no sense originally I don't intend to make sense of it myself lol