SELECT from two tables

Question

Hello, I have a problem writing a specific SELECT statement and I hope you'll help me out.
I have two tables:
Clients:
- ID integer (PK)
- Name_SecondName varchar(20)
- Gender char
- Balance integer
Investments:
- ID integer (PK)
- Amount integer
- Interest Numeric(3,2)
- Client_ID (FK)
My job is to display a number of men and a number of women who have at least one investment higher than $1000. I'll skip adding the data to the table, my point is just to find a proper construction for the SQL query. Right now I've got this:
SELECT COUNT(DISTINCT Client_ID), COUNT(DISTINCT Client_ID)
FROM Clients JOIN Investments
ON Clients.ID = Investments.Client_ID
WHERE Amount > 1000;
Obviously it twice displays the number of clients with an investment higher than $1000. But how do I specify that the first COUNT counts men (Gender='M') and second - women (Gender = 'F') ?? Can anyone help me?
Edited by: 934019 on 2012-05-13 12:10

Answer 1

I'm using Oracle Database 11g Express Edition Release 11.2.0.2.0 - Production
Here's the code:
CREATE TABLE Clients
Client_ID INTEGER PRIMARY KEY,
Name_SecondName VARCHAR(20),
Gender CHAR,
Balance INTEGER
CREATE TABLE Investments
Investment_ID INTEGER PRIMARY KEY,
Amount INTEGER,
Interest NUMERIC(3,2),
Client_ID INTEGER REFERENCES Clients(Client_ID)
INSERT INTO Clients VALUES (1, 'Brad_Pitt', 'M', 100000);
INSERT INTO Clients VALUES (2, 'Angelina_Jolie', 'F', 200000);
INSERT INTO Clients VALUES (3, 'George_Clooney', 'M', 250000);
INSERT INTO Clients VALUES (4, 'Meryl_Streep', 'F', 150000);
INSERT INTO Clients VALUES (5, 'Colin_Farrell', 'M', 200000);
INSERT INTO Clients VALUES (6, 'Scarlett_Johansson', 'F', 400000);
INSERT INTO Investments VALUES (1, 10000, 4.25, 4);
INSERT INTO Investments VALUES (2, 20000, 4.65, 3);
INSERT INTO Investments VALUES (3, 15000, 3.85, 2);
INSERT INTO Investments VALUES (4, 30000, 4.85, 6);
INSERT INTO Investments VALUES (5, 25000, 4.5, 3);
INSERT INTO Investments VALUES (6, 15000, 4.35, 5);
INSERT INTO Investments VALUES (7, 20000, 4.75, 6);
INSERT INTO Investments VALUES (8, 10000, 4.15, 1);
INSERT INTO Investments VALUES (9, 25000, 4.6, 3);
INSERT INTO Investments VALUES (10, 20000, 4.15, 4);
And now I make a SELECT statement as follows:
SELECT COUNT(DISTINCT Client_ID), COUNT(DISTINCT Client_ID)
FROM Clients NATURAL JOIN Investments
WHERE Investments. Amount > 15000;
The result is:
COUNT (DISTINCT Client_ID) *3*
COUNT(DISTINCT Client_ID) *3*
It now displays '3' because there are 3 clients who have at least one investment higher than 15000 (George Clooney, Meryl Streep and Scarlett Johansson).
So again the question is how to make the first COUNT count only men and the second COUNT - only women? I don't want it to display the clients - just the number of them.