Left Join where condition is not working with user define variable in python

Question

fetch = int(input("enter the patient id: "))

cursor.execute("SELECT \
        patients.Age AS patients, \
        diabetespatients.diabetes, diabetespatients.bp, diabetespatients.bmi, diabetespatients.Status AS records \
        FROM diabetespatients \
        LEFT JOIN patients ON diabetespatients.pid = patients.Pid \
        WHERE patients.Pid = fetch")
myresult = cursor.fetchall()
myresult

Error

1054 (42S22): Unknown column 'fetch' in 'where clause'

if I pass integer value then they working well....but if pass variable(with user input) then got an error

score 0 · Answer 1 · answered Dec 29 '20 at 19:11

Use a prepared statement:

cursor.execute("SELECT p.age AS patients, dp.diabetes, dp.bp, dp.bmi, dp.status AS records \
    FROM diabetespatients dp \
    INNER JOIN patients p ON dp.pid = p.pid \
    WHERE dp.pid = %s", (fetch,));

Note that I modified the query:

I suspect that you want an INNER JOIN rather than a LEFT JOIN - that's how your current query behaves anyway, because of the filtering in the WHERE clause on the LEFT JOINed table. I changed the code accordingly. You can change it back if you like (I changed the filtering so it is done on the "main" table instead)
table aliases make the query easier to write and read

Left Join where condition is not working with user define variable in python

1 Answers1