Hàm if () trả về một giá trị nếu một điều kiện là đúng hoặc giá trị khác nếu một điều kiện là sai.
Hàm if () trả về một giá trị nếu một điều kiện là đúng hoặc giá trị khác nếu một điều kiện là sai.FROM OrderDetails;
FROM OrderDetails;
Tóm tắt: Trong hướng dẫn này, bạn sẽ tìm hiểu cách sử dụng câu lệnh MySQL nếu thực thi một khối mã SQL dựa trên một điều kiện được chỉ định.: in this tutorial, you will learn how to use MySQL IF statement to execute a block of SQL code based on a specified condition.: in this tutorial, you will learn how to use MySQL IF statement to execute a block of SQL code based on a specified condition.
Lưu ý rằng MySQL có hàm if () khác với câu lệnh
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
3 được mô tả trong hướng dẫn này.Tuyên bố
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
3 có ba biểu mẫu: câu lệnh đơn giản ____ 15 & nbsp; câu lệnh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
6 và câu lệnh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
7.Câu lệnh mysql đơn giản DELIMITER $$ CREATE PROCEDURE GetCustomerLevel( IN pCustomerNumber INT, OUT pCustomerLevel VARCHAR(20)) BEGIN DECLARE credit DECIMAL(10,2) DEFAULT 0; SELECT creditLimit INTO credit FROM customers WHERE customerNumber = pCustomerNumber; IF credit > 50000 THEN SET pCustomerLevel = 'PLATINUM'; END IF; END$$ DELIMITER ;Code language: SQL (Structured Query Language) (sql)5
Câu lệnh
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 cho phép bạn thực thi một tập hợp các câu lệnh SQL dựa trên một điều kiện được chỉ định. Sau đây minh họa cú pháp của câu lệnh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5:IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
Trong cú pháp này:
- Đầu tiên, chỉ định một điều kiện để thực thi mã giữa
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2. Nếu SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4, các câu lệnh giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2 sẽ thực thi. Mặt khác, điều khiển được chuyển sang câu lệnh tiếp theo sau SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2. - Thứ hai, chỉ định mã sẽ thực thi nếu
SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4.
Chúng tôi sẽ sử dụng bảng
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
60 từ cơ sở dữ liệu mẫu để trình diễn:Xem thủ tục được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 sau đây.DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
Quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 chấp nhận hai tham số: DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
63 và DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64.- Đầu tiên, chọn
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
65 của khách hàng được chỉ định bởi DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
63 từ bảng DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
60 và lưu trữ nó trong biến cục bộ DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
68. - Sau đó, đặt giá trị cho tham số
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64 thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
81 nếu giới hạn tín dụng của khách hàng lớn hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82.
Tuyên bố này tìm thấy tất cả các khách hàng có giới hạn tín dụng lớn hơn
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82:SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
Đây là đầu ra một phần:
Các câu lệnh này gọi quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 cho khách hàng 141 và hiển thị giá trị của tham số DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
6 Vì khách hàng 141 có giới hạn tín dụng lớn hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, mức của nó được đặt thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
8 1 như mong đợi.Because the customer 141 has a credit limit greater than
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, its level is set to DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
81 as expected.Tuyên bố MySQL DELIMITER $$ CREATE PROCEDURE GetCustomerLevel( IN pCustomerNumber INT, OUT pCustomerLevel VARCHAR(20)) BEGIN DECLARE credit DECIMAL(10,2) DEFAULT 0; SELECT creditLimit INTO credit FROM customers WHERE customerNumber = pCustomerNumber; IF credit > 50000 THEN SET pCustomerLevel = 'PLATINUM'; END IF; END$$ DELIMITER ;Code language: SQL (Structured Query Language) (sql)6
Trong trường hợp bạn muốn thực hiện các câu lệnh khác khi
SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 trong nhánh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
3 không đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4, bạn có thể sử dụng câu lệnh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
6 như sau:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
8 Trong cú pháp này, nếu
SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4, DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
76 giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 và DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 thực thi. Mặt khác, DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
79 giữa thực thi DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2.Hãy để sửa đổi quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61.Đầu tiên, hãy bỏ thủ tục lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
7Sau đó, tạo quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 với mã mới:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
7Trong quy trình được lưu trữ mới này, chúng tôi bao gồm chi nhánh
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78. Nếu DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
68 không lớn hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, chúng tôi sẽ đặt cấp độ khách hàng thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 trong khối giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2.Truy vấn này tìm thấy khách hàng có giới hạn tín dụng nhỏ hơn hoặc bằng
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82:IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
5Hình ảnh này cho thấy đầu ra một phần:
Các câu lệnh sau đây gọi quy trình được lưu trữ cho số khách hàng
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
52 & nbsp; và hiển thị giá trị của tham số DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64:IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
9 Giới hạn tín dụng của khách hàng IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
52 nhỏ hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, do đó, tuyên bố trong chi nhánh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 thực thi và đặt giá trị của tham số DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64 thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78.The credit limit of the customer
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
52 is less than DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, therefore, the statement in the DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 branch executes and sets the value of the DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 parameter DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64 to DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78.Tuyên bố MySQL CALL GetCustomerLevel(447, @level); SELECT @level;Code language: SQL (Structured Query Language) (sql)1
Nếu bạn muốn thực thi các câu lệnh một cách có điều kiện dựa trên nhiều điều kiện, bạn sẽ sử dụng câu lệnh
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
91 sau:SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3Trong cú pháp này, nếu
SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4, DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
76 giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 và DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 thực thi. Mặt khác, DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
79 giữa thực thi DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2.Hãy để sửa đổi quy trình được lưu trữ
Đầu tiên, hãy bỏ thủ tục lưu trữ Sau đó, tạo quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 với mã mới:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
7Trong quy trình được lưu trữ mới này, chúng tôi bao gồm chi nhánh
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78. Nếu DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
68 không lớn hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, chúng tôi sẽ đặt cấp độ khách hàng thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 trong khối giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2.Truy vấn này tìm thấy khách hàng có giới hạn tín dụng nhỏ hơn hoặc bằng
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
91.Đầu tiên, hãy bỏ thủ tục lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
0Sau đó, tạo quy trình được lưu trữ
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
61 với mã mới:DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
7Trong quy trình được lưu trữ mới này, chúng tôi bao gồm chi nhánh
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78. Nếu DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
68 không lớn hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, chúng tôi sẽ đặt cấp độ khách hàng thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 trong khối giữa DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 và SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
2.- Truy vấn này tìm thấy khách hàng có giới hạn tín dụng nhỏ hơn hoặc bằng
- Hình ảnh này cho thấy đầu ra một phần:
- Các câu lệnh sau đây gọi quy trình được lưu trữ cho số khách hàng
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
52 & nbsp; và hiển thị giá trị của tham số DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64:IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
9 Giới hạn tín dụng của khách hàng IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
52 nhỏ hơn DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
82, do đó, tuyên bố trong chi nhánh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78 thực thi và đặt giá trị của tham số DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
69 DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
64 thành DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
78.The credit limit of the customer
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
09.Nếu bạn muốn thực thi các câu lệnh một cách có điều kiện dựa trên nhiều điều kiện, bạn sẽ sử dụng câu lệnh
IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
91 sau:SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3Trong cú pháp này, nếu
SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
3 đánh giá thành SELECT
customerNumber,
creditLimit
FROM
customers
WHERE
creditLimit > 50000
ORDER BY
creditLimit DESC;
Code language: SQL (Structured Query Language) (sql)
4, & nbsp; DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
76 trong nhánh DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
IN pCustomerNumber INT,
OUT pCustomerLevel VARCHAR(20))
BEGIN
DECLARE credit DECIMAL(10,2) DEFAULT 0;
SELECT creditLimit
INTO credit
FROM customers
WHERE customerNumber = pCustomerNumber;
IF credit > 50000 THEN
SET pCustomerLevel = 'PLATINUM';
END IF;
END$$
DELIMITER ;
Code language: SQL (Structured Query Language) (sql)
5 thực thi; Nếu không, IF condition THEN
statements;
END IF;
Code language: SQL (Structured Query Language) (sql)
97 tiếp theo được đánh giá.Mysql nếu khác.Tuy nhiên, nếu () hàm có thể được sử dụng độc lập với các truy vấn MySQL trực tiếp, MySQL nếu khác được sử dụng như một câu lệnh như một phần của các quy trình hoặc chức năng được lưu trữ.IF() function can be used independently with MySQL queries directly, however, MySQL IF ELSE is used as a statement as part of the stored procedures or functions.IF() function can be used independently with MySQL
queries directly, however, MySQL IF ELSE is used as a statement as part of the stored procedures or functions.