COBOL Tutorial Series: Working with Database - Session 5

#cobol #database #tutorial #programming

Hello, I'm Duke

Today I will show you how to work with Database by COBOL. But, you should read all of the previous sessions to know more about the COBOL

Okay, let's start

1.Steps to set up a COBOL connection to MySQL

- Install MySQL Client

sudo apt install default-mysql-client

- Create a Customer table in MySQL database

CREATE TABLE customers (
    customerNumber INT(11) NOT NULL,
    customerName VARCHAR(50) NOT NULL,
    contactLastName VARCHAR(50) NOT NULL,
    contactFirstName VARCHAR(50) NOT NULL,
    phone VARCHAR(50) NOT NULL,
    addressLine1 VARCHAR(50) NOT NULL,
    addressLine2 VARCHAR(50) DEFAULT NULL,
    city VARCHAR(50) NOT NULL,
    state VARCHAR(50) DEFAULT NULL,
    postalCode VARCHAR(15) DEFAULT NULL,
    country VARCHAR(50) NOT NULL,
    creditLimit DECIMAL(10,2) DEFAULT NULL,
    PRIMARY KEY (customerNumber)
);

INSERT INTO customers (customerNumber, customerName, contactLastName, contactFirstName, phone, addressLine1, addressLine2, city, state, postalCode, country, creditLimit) VALUES
(1, 'Nguyen Thanh Duc', 'Nguyen', 'Thanh Duc', '+84826540246', 'Nguyen Van Linh', 'Phuoc My', 'Da Nang', NULL, '550000', 'Viet Nam', 9000000.00),
(2, 'Tran Thi B', 'Tran', 'Thi B', '0123456788', '456 Nguyen Van Linh', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 2000.00),
(3, 'Le Van C', 'Le', 'Van C', '0123456787', '789 Bach Dang', 'Hoa Hai', 'Da Nang', NULL, '550000', 'Viet Nam', 1500.00),
(4, 'Hoang Thi D', 'Hoang', 'Thi D', '0123456786', '321 Nguyen Huu Tho', 'My An', 'Da Nang', NULL, '550000', 'Viet Nam', 1200.00),
(5, 'Phan Van E', 'Phan', 'Van E', '0123456785', '654 Tran Phu', 'Son Tra', 'Da Nang', NULL, '550000', 'Viet Nam', 1100.00),
(6, 'Ngo Thi F', 'Ngo', 'Thi F', '0123456784', '987 Hoang Sa', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 1400.00),
(7, 'Vo Van G', 'Vo', 'Van G', '0123456783', '159 Le Loi', 'Hai Chau', 'Da Nang', NULL, '550000', 'Viet Nam', 1300.00),
(8, 'Bui Thi H', 'Bui', 'Thi H', '0123456782', '753 Nguyen Van Troi', 'An Hai Dong', 'Da Nang', NULL, '550000', 'Viet Nam', 1250.00),
(9, 'Ngo Van I', 'Ngo', 'Van I', '0123456781', '258 Hoang Dieu', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 1150.00),
(10, 'Pham Thi J', 'Pham', 'Thi J', '0123456780', '852 Quang Trung', 'Nui Thanh', 'Da Nang', NULL, '550000', 'Viet Nam', 1050.00),
(11, 'Truong Van K', 'Truong', 'Van K', '0123456790', '963 Nguyen Thai Hoc', 'Khuong Ha', 'Da Nang', NULL, '550000', 'Viet Nam', 1350.00),
(12, 'Dang Thi L', 'Dang', 'Thi L', '0123456791', '147 To Hien Thanh', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 1450.00),
(13, 'Vu Van M', 'Vu', 'Van M', '0123456792', '258 Le Duan', 'My Khe', 'Da Nang', NULL, '550000', 'Viet Nam', 1550.00),
(14, 'Luu Thi N', 'Luu', 'Thi N', '0123456793', '369 Hoang Sa', 'Hoa Khue', 'Da Nang', NULL, '550000', 'Viet Nam', 1650.00),
(15, 'Nguyen Van O', 'Nguyen', 'Van O', '0123456794', '456 Tran Hung Dao', 'Nam Duong', 'Da Nang', NULL, '550000', 'Viet Nam', 1750.00),
(16, 'Ngoc Thi P', 'Ngoc', 'Thi P', '0123456795', '567 Hoang Dieu', 'Chinh Gian', 'Da Nang', NULL, '550000', 'Viet Nam', 1850.00),
(17, 'Tran Van Q', 'Tran', 'Van Q', '0123456796', '678 Nguyen Tri Phuong', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 1950.00),
(18, 'Le Thi R', 'Le', 'Thi R', '0123456797', '789 Nguyen Thi Minh Khai', 'Thanh Khe', 'Da Nang', NULL, '550000', 'Viet Nam', 2050.00),
(19, 'Phan Van S', 'Phan', 'Van S', '0123456798', '890 Phan Chu Trinh', 'Son Tra', 'Da Nang', NULL, '550000', 'Viet Nam', 2150.00),
(20, 'Vo Thi T', 'Vo', 'Thi T', '0123456799', '901 Hoang Sa', NULL, 'Da Nang', NULL, '550000', 'Viet Nam', 2250.00);

- Test connection to MySQL database

mysql -h <host> -P <port> -u <user> -p<password> -e "SELECT 1"

2.Create mysql.cbl file

       IDENTIFICATION DIVISION.
       PROGRAM-ID. DUKE-CONNECT-MYSQL.

       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       SOURCE-COMPUTER. GNUCOBOL.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 WS-COMMAND PIC X(1000).
       01 WS-RETURN-CODE PIC S9(4) COMP.
       01 WS-HOSTNAME PIC X(60) VALUE '<your hostname>'.
       01 WS-PORT PIC 9(6) VALUE <your port>.
       01 WS-USERNAME PIC X(10) VALUE '<your username>'.
       01 WS-PASSWORD PIC X(30) VALUE '<your password>'.
       01 WS-DBNAME PIC X(10) VALUE 'defaultdb'.
       01 WS-CUSTOMER-QUERY PIC X(30) VALUE 'SELECT * FROM customers'.

       PROCEDURE DIVISION.

       STRING
           'mysql '        DELIMITED BY SIZE
           '-h '          DELIMITED BY SIZE
           WS-HOSTNAME    DELIMITED BY SIZE
           ' -P '         DELIMITED BY SIZE
           WS-PORT        DELIMITED BY SIZE
           ' -u '         DELIMITED BY SIZE
           WS-USERNAME    DELIMITED BY SIZE
           ' -p'          DELIMITED BY SIZE
           WS-PASSWORD    DELIMITED BY SIZE
           ' -D '         DELIMITED BY SIZE
           WS-DBNAME      DELIMITED BY SIZE
           ' -e "'        DELIMITED BY SIZE
           WS-CUSTOMER-QUERY DELIMITED BY SIZE
           '"'            DELIMITED BY SIZE
           INTO WS-COMMAND
       END-STRING

       CALL "system" USING WS-COMMAND GIVING WS-RETURN-CODE.

       IF WS-RETURN-CODE = 0
          DISPLAY 'Connected and query executed!'
       ELSE
          DISPLAY 'Failed to execute command, error code: '
          WS-RETURN-CODE
       END-IF.

       STOP RUN.

- Compile and run it