SQL Join - Odd results

[brian47374]

I am trying to do a JOIN on two tables. 

Table 1 has these fields:

-          Handle

-          Variant SKU

-          Variant Barcode

Table 2 has these fields:

-          SKU

-          Barcode

-          Brand

-          Description

SELECT TABLE1.`handle`, TABLE1.`Variant SKU`, TABLE1.`Variant Barcode`, TABLE2.`SKU`, TABLE2.Barcode FROM TABLE1 inner JOIN TABLE2

When I run the statement above, I get the same Variant SKU for every result while the SKU from Table 2 is unique as it should be. Not only that, but the handle (which is the product name) repeats itself for every result and it should not as there are about 550 different products.See 5045.PNG file attached. The VARIANT SKU should be different such as the SKU as should the HANDLE and the VARIANT BARCODE. 

And then I execute this statement below, not only do I get the same repeated handle (product), but the Variat SKU, Variant Barcode, and SKU data is blank. Only the handle and barcode are showing up. Attachment REPEAT.PNG

SELECT TABLE1.`handle`, TABLE1.`Variant SKU`, TABLE1.`Variant Barcode`, TABLE2.`SKU`, TABLE2.Barcode 

FROM TABLE1 

inner JOIN TABLE2 

on TABLE1.`Variant SKU` = TABLE2.`SKU` and TABLE1.`Variant Barcode` <> TABLE2.`Barcode`

Any help on this would be greatly appreciated.

Edited September 6, 2017 by brian47374

[justsomeguy]

When you join a table without any conditions it's just going to produce every possible combination of records.

You didn't show the data that you're joining, just the results, so I can't suggest why it's producing that output, other than to say that it's matching what you're telling it to do.  You're telling it to return records that have the same SKU and different barcodes, so maybe there are records on those table with blank values.  I see at least one blank SKU in the first result.  It also looks like your "variant SKU" and "variant barcode" fields start with a quotation mark and the other ones don't, those are always going to be different.

[brian47374]

I have provided a couple of screen shots. Hopefully this is what you are looking for as far as data. Also, how do I remove the ‘ from the beginning of the SKU’s and the Barcodes? I imported a CSV file and for some reason it tends to do that when it feels like it, but not all the time. Table 1 is first and then Table 2.

Edited September 14, 2017 by brian47374

[justsomeguy]

If the data in those fields should never have an apostrophe then you can write an update query to use MySQL's string functions to remove it from existing data, but you really need to make sure that the data you're importing is clean in the first place.  Nothing about computers is random, computers never feel like doing anything.  Sometimes your data is bad, and sometimes it's not.  Like they say, garbage in, garbage out.  The values in your fields are not the same when one of them includes extra characters.  You need to make sure that the process to export the CSV data is using the same rules that the import does.

[brian47374]

I have no control over the ' being inserted. It is exported from our system in that manner for whatever reason. I have researched this issue and it seems to be a common issue with Excel and CSV files. Not a single one of the proposed solutions works for removing the '. Is there a way to truncate the ' out? 

[justsomeguy]

If the field should never have those characters, then you can run a SQL query to remove them from the fields.  e.g.:

https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_replace

[brian47374]

Alright, I got the (‘) removed from all of the files. So, I have the same fields in both tables now. In Table 1 there are 46 columns, and in Table 2 there are 4 columns.

·         Handle (Product name) (Table 1 & Table 2)

·         Vendor (Table 1 & Table 2)

·         Variant SKU (Table 1 & Table 2)

·         Variant Barcode (Table 1 & Table 2)

·          

Table 1 has 867 records (see screenshot)

Table 2 has 552 records  (see screenshot)

However, when I use the following statement, I got I get 17172 results which I have no idea how that is possible.

 

SELECT TABLE1.`handle`, TABLE1.`Variant SKU`, TABLE1.`Variant Barcode`, TABLE2.`Variant SKU`, `TABLE2`.`Variant Barcode` FROM TABLE1 inner JOIN TABLE2 on TABLE1.`Variant SKU` = TABLE2.`Variant SKU` and TABLE1.`Variant Barcode` <> TABLE2.`Variant Barcode`

 

There are no unique fields.

Why am I getting this many results?

Then, when I join and leave out the barcodes, I get closer to what I am looking for in screenshot Join 2 (not allowed to upload). But again, I get FAR more results than I should!

I am wanting to see where the Variant SKU matches and the Barcode doesn’t. Also, where the SKU doesn’t and the barcodes do. They don’t have to be in the same query, but it would be nice if they do.

 

Edited September 21, 2017 by brian47374

[justsomeguy]

Why am I getting this many results?

Because you're telling it to return every combination of rows where the SKUs match but the barcodes are different.  If your SKUs aren't unique, that could be a lot of rows.  It also looks like you have a lot of rows with blank values, if there are two rows with blank SKUs it's going to return those because they match.  You might want to exclude blank values in the join condition also.

[justsomeguy]

Whose fault is what?  Are you going to make several non-sequitor posts and eventually follow that up by adding some spam links in your signature?

[brian47374]

Quote

Whose fault is what?  Are you going to make several non-sequitor posts and eventually follow that up by adding some spam links in your signature?

What the ???? I have no idea what you are talking about. I am here to solve a problem. Why in the world would you even bring up SPAM links in my signature. Obviously I am not a pro like you, and that is WHY I am here. It has been years since I done anything with SQL. And when I did, about 10 years ago, it was on the IBM AS400 platform. I wish I would have kept my notes. If I would have, I wouldn't be here.  

I appreciate any and all help that I can get. Maybe one day it will all come back to me. Sorry to be a burden by asking questions. 

[brian47374]

When I included the <> ' ' clause, I got two results. Both of which I know are valid. However, when I added the clause, I got NULL in the last two columns without column names. I find that strange. I would think that I would at least get a column name. Did I do something wrong?

Here is my updated statement: 

SELECT TABLE1.`handle`, TABLE1.`Variant SKU`, TABLE1.`Variant Barcode`, TABLE2.`Variant SKU`, `TABLE2`.`Variant Barcode` 

FROM TABLE1 

inner JOIN TABLE2 on TABLE1.`Variant SKU` = TABLE2.`Variant SKU` 

and TABLE1.`Variant SKU` <> ' ' 

and TABLE2.`Variant SKU` <> ' ' 

and TABLE1.`Variant Barcode` <> TABLE2.`Variant Barcode`

 

[justsomeguy]

That message wasn't directed at you, there was another user that got banned and his posts removed, including the one I replied to

You can probably leave out one of those conditions, since you're requiring that the 2 SKU columns are the same, you only need to check the value of one of them instead of both of them.

That output seems strange though, I've never seen it return a column without a name.

[brian47374]

Well... leave it to me to "break it"... lol 

Thanks for your help!