Translate the following question to SQL: How long does student Linda Smith spend on the restaurant in total?

Schema: CREATE TABLE Student (
    StuID INTEGER   PRIMARY KEY,
    LName VARCHAR(12),
    Fname VARCHAR(12),
    Age INTEGER,
    Sex VARCHAR(1),
    Major INTEGER,
    Advisor INTEGER,
    city_code VARCHAR(3)
);

CREATE TABLE Restaurant (
    ResID INTEGER   PRIMARY KEY,
    ResName VARCHAR(100),
    Address VARCHAR(100),
    Rating INTEGER
);

CREATE TABLE Type_Of_Restaurant (
    ResID INTEGER,
    ResTypeID INTEGER,
    FOREIGN KEY (ResTypeID) REFERENCES Restaurant_Type(ResTypeID),
    FOREIGN KEY (ResID) REFERENCES Restaurant(ResID)
);

CREATE TABLE Restaurant_Type (
    ResTypeID INTEGER   PRIMARY KEY,
    ResTypeName VARCHAR(40),
    ResTypeDescription VARCHAR(100)
);

CREATE TABLE Visits_Restaurant (
    StuID INTEGER,
    ResID INTEGER,
    Time TIMESTAMP,
    Spent FLOAT,
    FOREIGN KEY (ResID) REFERENCES Restaurant(ResID),
    FOREIGN KEY (StuID) REFERENCES Student(StuID)
);
user
SELECT sum(Spent) FROM Student JOIN Visits_Restaurant ON Student.StuID = Visits_Restaurant.StuID WHERE Student.Fname = "Linda" AND Student.Lname = "Smith";
assistant