For example, when running a query like this one which fetches the longest film s every actor in the Sakila database played in :. Sometimes, having some excess columns is not going to be a problem, but sometimes it is. How to remove it? Which is really quite convenient!
We want to project everything, except this one column. But none of the more popular SQL databases support this syntax. In the outer query, we have to use some slightly different syntax to unnest the record again e.
For all practical purposes, this essentially just means that we can nest records and collections. Conveniently, we can also reference a table without its column names in the projection, such as:. For more details about TOP N per category queries, see this blog post. View all posts by lukaseder. Does this technique only help with omitting derived columns generated during the join, though?
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Create a view. Yes, in the view creation statement, you will have to list each This is not a generic solution, but some databases allow you to use regular expressions to specify the columns. You will see the select query. Just take out the column you want to exclude and you have your preferred select query. If you are using DataGrip you can do the following:.
Here is a link for an example on how to do it. In your case, expand columns of that database in the object explorer. Drag the columns in to the query area. And then just delete one or two columns which you don't want and then run it. I'm open to any suggestions easier than this. Only one way to achieve this giving column name. There is no other method found. You must have to list all column name. Learn more. How to select all the columns of a table except one column? Ask Question. Asked 5 years, 6 months ago.
Active 1 month ago. Viewed k times.
Is there any other way to do it? Giri Prasad Giri Prasad 1 1 gold badge 6 6 silver badges 13 13 bronze badges.
Which DBMS you are using?In the script above, we create a dummy database called BookStore. The database contains two tables: Books1 and Books2. Both tables contain 4 columns: idnamecategory and price. The above script inserts 10 records into the Books1 table and 10 records into the Books2 table. It is important to mention that the last 5 records in the Books1 table and the first 5 records in the Books2 table are the same. You can see that the records from ids 6 to 10 are the same in both tables.
You can see that only records with ids 1 to 5 have been selected from the Books1 table since the records with ids 6 to 10 also exist in the Books2 table. You can see that only records with ids 11 to 15 have been selected since records with ids from the Books2 table, also exist in the Books1 table.
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For example, the following EXCEPT statement will return all the records from the Books1 table where the price is less than or equal to Hence, we are only left with the records from the Books table, where the price is not greater than There are two major differences:. Here is an example of how a NOT IN statement can be used to filter all records from the Books1 table, that also exist in the Books2 table:. You can see that here the comparison between the first and second columns is only based on the id column.
In this article, we looked at how to use an EXCEPT statement to filter records from two tables as well as from a single table. USE BookStore. USE BookStore. Author Recent Posts. Ben Richardson. It offers a full range of SQL training from introductory courses through to advanced administration and data warehouse training — see here for more details. Acuity has offices in London and Guildford, Surrey.
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It only takes a minute to sign up. IT would be very convenient for selecting all the non-blob or non-geometric columns from a table. I think this is a quite interesting question so I googled a little bit and came across an interesting article on postgresonline. You could create a function that does something like that. Such topics were also discussed on the mailing lists, but the overall consensus was pretty much the same: query the schema. I'm sure that there are other solutions but I think they will all involve some kind of magic schema-queriying-foo.
The real answer is that you just can not practically.
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This has been a requested feature for decades and the developers refuse to implement it. The popular answer suggesting querying the schema tables will not be able to run efficiently because the Postgres optimizer considers dynamic functions a black box see the test case below.
That means that indexes will not be used and joins will not be done intelligently. You would be much better off with some sort of macro system like m4. At least it will not confuse the optimizer but it may still confuse you. Without forking the code and writing the feature yourself or using a programming language interface you are stuck. I wrote a simple proof of concept below showing how bad performance would be with a very simple dynamic execution in plpgsql.
Notice also, that below I have to coerce a function returning a generic record into a specific row type and enumerate the columns.
Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. When the columns are not a MultiIndex, df. Don't use ix. It's deprecated. The most readable and idiomatic way of doing this is df. Note that by default. If you want to permanently remove b from dfdo df. I think the best way to do is the way mentioned by Salvador Dali.
Not that the others are wrong. Because when you have a data set where you just want to select one column and put it into one variable and the rest of the columns into another for comparison or computational purposes. Then dropping the column of the data set might not help. Of course there are use cases for that as well. I think a nice solution is with the function filter of pandas and regex match everything except "b" :.
Learn more. How to select all columns, except one column in pandas?
List all columns in specific table in Snowflake
Ask Question. Asked 5 years, 5 months ago. Active 30 days ago. Viewed k times. Despite the original title, the linked question is "Why doesn't this specific syntax work", whereas this question is a more general "What is the best way to do this". May 21 '19 at I'm sorry but I don't agree with the edit you've made to the title on that post, so I've rolled it back. It's true that the intent of the OP was to question the syntax, but the post has grown to address the more broad question of how to delete a column.
The answers in this post are carbon copies of the highest upvoted post there. The dupe stays. Note this question is being discussed on Meta. Active Oldest Votes. Will 3, 2 2 gold badges 30 30 silver badges 45 45 bronze badges. Marius Marius Not bad, but mike's solution using drop is better IMO. I actually agree that mike's solution using drop is better - I do think it's useful to discover that single-level columns are arrays you can work with, but specifically for dropping a column, drop is very readable and works well with complex indexes.
Thank you for this greate answer.
What about when you have more than 1 column to be ignored? Marius Does this work with multiple columns say two? Also works on a multiindex just like you'd expect it to. Seems to use list vs tuple to determine if you want multiple columns list or referring to a multiindex tuple.Removes all context filters in the table except filters that have been applied to the specified columns.
This function is not used by itself, but serves as an intermediate function that can be used to change the set of results over which some other calculation is performed. This function is not supported for use in DirectQuery mode when used in calculated columns or row-level security RLS rules.
However, if the column CalendarYear is used to slice the PivotTable, the results are different. Skip to main content. Contents Exit focus mode. Return value A table with all filters removed except for the filters on the specified columns. Remarks This function is not used by itself, but serves as an intermediate function that can be used to change the set of results over which some other calculation is performed.
In effect, ALL Table returns all of the values in the table, removing any filters from the context that otherwise might have been applied. This function is useful when you are working with many levels of grouping, and want to create a calculation that creates a ratio of an aggregated value to the total value.
ALL Column[, Column[, …]] Removes all filters from the specified columns in the table; all other filters on other columns in the table still apply. All column arguments must come from the same table.
The ALL Column variant is useful when you want to remove the context filters for one or more specific columns and to keep all other context filters. Removes all context filters in the table except filters that are applied to the specified columns.
This is a convenient shortcut for situations in which you want to remove the filters on many, but not all, columns in a table. Example The following example presents a formula that you can use in a measure. Yes No. Any additional feedback? Skip Submit. Is this page helpful? The table over which all context filters are removed, except filters on those columns that are specified in subsequent arguments.
Removes all filters from the specified table. Removes all filters from the specified columns in the table; all other filters on other columns in the table still apply.