Why is MY SQL query returning Duplicate results?

Why is MY SQL query returning Duplicate results?

I recently reviewed a SQL query that was returning duplicate results. Since I expected, and needed, a single result from the query this was a problem. Here’s an explanation of why this bug occurred, and several different ways it can be resolved.

How to do random duplicate rows in the result view?

In short, if you have dbeaver set to show 200 rows for its result set , when you scroll past the first 200, dbeaver will rerun the query, and from the result, it will return rows 201-350 and append that to the first 200 rows.

How can I get rid of duplicates in my query?

My first attempt to remove the duplicates was to add the DISTINCT keyword to my query, but that didn’t fix the problem – I was still seeing duplicates. As I was looking at the result set more closely I realized that the problem was in how the query was structured and the columns that it was returning in the results.

What to do with duplicate rows in Excel?

What it should do, is replace rows 1-200 with the results from the second query, but what it does instead is append rows 201-350 from the second query to rows 1-200 from the first query.

Why do some tables return a unique row?

Some of the tables that I was joining had one to many relationships with rows in other tables. That meant that when my result set was created, each of those many results got returned as its own unique row.

What does it mean when a result is returned four times?

That meant that when my result set was created, each of those many results got returned as its own unique row. For example, if I had one user joined to a table with four different category entries, the user would be returned in my result set four times, once for each category entry.

Do you ever get duplicate rows in BigQuery?

The easiest way is to re-create the whole table in place using DISTINCT. You need to use the same parameters (PARTITION BY) for the table. This processed about 320MB and consumed 2 minutes 15 seconds of slot time. Running the query to examine the data shows it is now deduplicated:

How to split a sales query into two queries?

That way it’s easier to understand the steps that were applied to the sales query before the merge. To do this operation, you right-click the Merge with Prices table step and select the Extract Previous option. You’ll then be prompted with a dialog to give your new query a name. This will effectively split your query into two queries.

Is it possible to return duplicates in Excel?

Looking across the result set, we can see that the “duplicate” results are not actually duplicates – the same user is being returned with multiple categories, making each row unique. So if we only want to return one of each user, how do we do it?

How to prevent duplicate rows in group by clause?

The GROUP BY clause at the end ensures only a single row is returned for each unique combination of columns in the GROUP BY clause. This should prevent duplicate rows being displayed in your results.

Is it possible to retrieve duplicate nodes in XML?

It gets a bit more complicated if you have attributes in the xml, but it is still possible to retrieve unique xml nodes. On the flip side, it is also possible to only return xml nodes that are duplicated in the xml instance. All the examples can be downloaded here

What does it mean when there are duplicates in a table?

If any rows are returned, that means we have duplicates. In this example, our results look like this: In the previous step, our query returned a list of duplicates. Now, we want to return the entire record for each duplicate row. To accomplish this, we’ll need to select the entire table and join that to our duplicate rows.

When do you need a table name in a query?

The table names are only required in the FROM, JOIN, and ON clauses, and in the latter, only because the relating column, CustomerID, has the same name in both tables. The query syntax shown above follows ANSI (American National Standards Institute) rules and should work in the latest versions of all relational databases.