使用以pk分组并具有count（distinct column_name）= 2的column_name IN（'one'，'two'）的查询返回空

Question

Using IN to select a dynamic list of software names that a computer must have to be matched, and the data exists in the database for a known value, the result when using:

GROUP BY id
HAVING COUNT(DISTINCT column_name) = count_of_list_values;

returns an empty result set when it should be returning the value expected. NOTE it works when you are searching for a single list item, this issue is when that list expands to more than one.

Plenty of Google searches, resulting in nothing useful... other than that using phpmyadmin, i have been trying to figure out why it is failing.

Isolated the area where it seems to choking and trying different things with the query to try to get it to work.

this is the section of the query that i am using.

SELECT
        am_software_archive.asset_name
    FROM
        am_software_archive
    WHERE
        LOWER(am_software_archive.sw_name) IN('nodejs', 'visio 2013')
    GROUP BY
        am_software_archive.id
    HAVING
        COUNT(
            DISTINCT am_software_archive.sw_name
        ) = 2

The data in this table exists and is valid so it should work... The table definition

CREATE TABLE IF NOT EXISTS am_software_archive(
                    id BIGINT NOT NULL UNIQUE,
                    asset_name VARCHAR(10) NOT NULL,
                    sw_name VARCHAR(150) NOT NULL,
                    sw_developer BIGINT NOT NULL,
                    sw_key VARCHAR(50) DEFAULT NULL,
                    sw_osver VARCHAR(15) DEFAULT NULL,
                    CONSTRAINT PK_software PRIMARY KEY(id, asset_name),
                    INDEX idx_sw_name_asset(asset_name,sw_name),
                    INDEX idx_sw_key_asset_name(asset_name,sw_key),
                    INDEX idx_sw_name_sw_key(sw_name,sw_key),
                    INDEX idx_osver_sw_name(sw_name,sw_osver),
                    INDEX idx_osver_asset_name(asset_name,sw_osver)
                )

In my database the expected result would be: "ABX50269"

Actual results well are empty, but shouldn't be.

Answer 1

You group by the id , which is unique so there cannot ever be two or more (different) sw_name per id .

As asset_name is the column in the list for SELECT , I think you actually want to group by asset_name .