BOTJr. BOTJr. - 1 month ago 9
MySQL Question

inner join not giving results as expected

Product_table


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Product_table_link


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This be the
product_table
data that is stored inside the database.

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This is the
product_table_link
data that is present inside the DB.I was trying to join these two tables where the
product code=something
.For instance let us take
xyz
as the product.

I was hoping to get the combined results of the two without any nulls present.

I tried :

SELECT s1.* FROM (SELECT p1.* FROM product_table p1 INNER JOIN product_table_link p2
ON p1.product_code=p2.product_code ) s1 WHERE product_code="xyz"


But the result is not the combination of the both tables rather it shows me the
product_table
.

CREATE TABLE `product_table` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`product_name` varchar(60) NOT NULL,
`product_code` varchar(60) NOT NULL,
`product_description` text,
`product_type` varchar(20) NOT NULL,
`product_image_path` varchar(60) NOT NULL,
`product_company_name` varchar(20) NOT NULL,
`product_company_id` varchar(60) NOT NULL,
`product_landing_page` varchar(15) NOT NULL,
`product_shape` varchar(20) DEFAULT NULL,
`product_flavour` varchar(20) NOT NULL,
`product_veg_mark` varchar(8) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `unique` (`product_code`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1

CREATE TABLE `product_table_link` (
`product_code` varchar(60) NOT NULL,
`product_weight` varchar(5) NOT NULL,
`product_price` int(5) NOT NULL,
`product_quantity` int(5) NOT NULL,
PRIMARY KEY (`product_code`,`product_weight`),
CONSTRAINT `product_table_link_ibfk_1` FOREIGN KEY (`product_code`) REFERENCES `product_table` (`product_code`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1


How do i get the combined results of the two tables?

Answer

Change your subquery to this

SELECT * FROM product_table p1 INNER JOIN product_table_link p2 
ON p1.product_code=p2.product_code

You were selecting just from p1.

You were doing select p1.* which will only select rows from p1. Inner join means you want to select rows from different tables on the basis of some conditions. You need to do select * which will select all the rows filtered from the join condition.

Your simplified final query.

SELECT s1.* FROM (SELECT p1.*,p2.product_weight,p2.product_price,p2.product_quantity 
FROM product_table p1 INNER JOIN product_table_link p2 
ON p1.product_code=p2.product_code) 
    s1 WHERE s1.product_code="xyz"