MYSQL 和 PHP 中的 JOIN 查询

Question

I am going to generate specific information from all the tables in MYSQL. I have 5 tables in my database. Ie:

1. advertiser

   CREATE TABLE `advertiser` ( `Adv_id` int(11) NOT NULL AUTO_INCREMENT, `Name` char(20) NOT NULL, `F_Name` char(20) NOT NULL, `Address` varchar(40) NOT NULL, `CNIC` int(13) NOT NULL, `Contact` int(11) NOT NULL, `Monthly_fee` varchar(10) NOT NULL, `Region` varchar(10) NOT NULL, `Reg_date` varchar(10) NOT NULL, PRIMARY KEY (`Adv_id`) ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;

2. company_information

   CREATE TABLE `company_information` ( `Company_id` int(11) NOT NULL AUTO_INCREMENT, `Company_Name` varchar(20) NOT NULL, `Company_Contact` int(11) NOT NULL, `Company_Address` varchar(30) NOT NULL, PRIMARY KEY (`Company_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

3. advertisement

   CREATE TABLE `advertisement` ( `Ads_id` int(11) NOT NULL AUTO_INCREMENT, `Adv_id_id` int(11) NOT NULL, `Company_id` int(11) NOT NULL, `Ads_Title` varchar(20) NOT NULL, `Ads_Description` varchar(40) NOT NULL, `Ads_Image` varchar(50) NOT NULL, PRIMARY KEY (`Ads_id`), KEY `Adv_id` (`Adv_id_id`), KEY `Company_id` (`Company_id`), CONSTRAINT `Adv_id` FOREIGN KEY (`Adv_id_id`) REFERENCES `advertiser` (`Adv_id`) ON DELETE CASCADE ON UPDATE CASCADE, CONSTRAINT `advertisement_ibfk_1` FOREIGN KEY (`Company_id`) REFERENCES `company_information` (`Company_id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;

4. ads_type

   CREATE TABLE `ads_type` ( `Ads_type_id` int(11) NOT NULL AUTO_INCREMENT, `Advertisement_id` int(11) NOT NULL, `Full_Channel_Ads` varchar(30) NOT NULL, `Logo_Ads` varchar(30) NOT NULL, `Com_Break_Ads` varchar(30) NOT NULL, PRIMARY KEY (`Ads_type_id`), KEY `Advertisement_id` (`Advertisement_id`), CONSTRAINT `Advertisement_id` FOREIGN KEY (`Advertisement_id`) REFERENCES `advertisement` (`Ads_id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

5. ads_date

   CREATE TABLE `ads_date` ( `Ads_date_id` int(11) NOT NULL AUTO_INCREMENT, `Ads_id` int(11) NOT NULL, `Starting_Date` varchar(30) NOT NULL, `Expiry_Date` varchar(30) NOT NULL, PRIMARY KEY (`Ads_date_id`), KEY `Ads_id` (`Ads_id`), CONSTRAINT `Ads_id` FOREIGN KEY (`Ads_id`) REFERENCES `advertisement` (`Ads_id`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=latin1;

I want to retrive

• Name, CNIN, and Contact from table Advertiser
• Company_Name from company_information
• Ads_Title from Advertisement
• Starting_Date and Expiry_Date From ads_date.

This Query work well for the above rows :

SELECT * 
    FROM ads_date a
    JOIN advertisement ci ON ci.Ads_id = a.Ads_id
    JOIN company_information ar ON ar.Company_id = ci.Company_id
    JOIN advertiser ad ON ad.Adv_id = ci.Advertiser_id
    WHERE Expiry_Date >= CURDATE()

Problem: I also want to retrive Advertisement_type from ads_type. how can I do this with a JOIN query? Can any one explain?

Answer 1

You'll need another join :

SELECT * 
FROM   ads_date a
JOIN   advertisement ci ON ci.Ads_id = a.Ads_id
JOIN   company_information ar ON ar.Company_id = ci.Company_id
JOIN   advertiser ad ON ad.Adv_id = ci.Advertiser_id
JOIN   ads_type at ON  at.Advertisement_id = ci.Ads_id -- Here
WHERE  Expiry_Date >= CURDATE()

Answer 2

Please try the below query:

SELECT * 
    FROM ads_date a
    JOIN advertisement ci ON ci.Ads_id = a.Ads_id
    JOIN company_information ar ON ar.Company_id = ci.Company_id
    JOIN advertiser ad ON ad.Adv_id = ci.Advertiser_id

    JOIN ads_type at ON at.Advertisement_id =ci.Ads_id

    WHERE Expiry_Date >= CURDATE()

Answer 3

Add another join as

JOIN   ads_type at ON  at.Advertisement_id = ci.Ads_id

Then use group_by at.Advertisement_id to avoid repetition.