But many times you may require using all the columns from a table except a couple of them. For example you may have a table containing twelve columns from which you require only eleven columns. But what if the column we do not require contains a large amount of BLOB data. It is inefficient to include the BLOB column in the query as it will unnecessarily increase the query load.Disablehwacceleration windows 10
What we want is to select all the columns except the BLOB column. The following php function will return all the column names for a given table. Now we create a function that returns a comma separated list of column names which we can then pass to the SELECT statement. The function also takes a array of column names we want to exclude. There are many cases when this might be useful. Take a typical example. There are many instances in the application where you have to shuffle data from the server to the client quickly.
The extra overhead of a single query on the server is negligible in comparison to the amount of data transfer saved by dropping unrequested columns. One other thing to point out. This is a really bad idea.Folliculinum
When you would add columns to the table definition they transparently get inserted into a query like this. Thanks for all the comments guys! I completely agree with Onno. But it still is a lot easy for me to use the above code while developing a quick prototype php application as I already said in my previous comment. Not sure what you really mean. The idea is to not select the columns we want so that we can reduce the query load. Just found your site — enjoying it quite a bit so far!!
Great site! Web scraping tutorial.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.Ktabs crack
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? You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. This site uses Akismet to reduce spam.
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I'm trying to use a select statement to get all of the columns from a certain MySQL table except one. Is there a simple way to do this? In mysql definitions manual there is no such thing.
But if you have a really big number of columns col1If you are looking to exclude the value of a field, e. However, if you want a lot of columns, then you might just want to do a:.
While trying the solutions by Mahomedalid and Junaid I found a problem. So thought of sharing it. If the column name is having spaces or hyphens like check-in then the query will fail. The simple workaround is to use backtick around column names. The modified query is below. If the column that you didn't want to select had a massive amount of data in it, and you didn't want to include it due to speed issues and you select the other columns often, I would suggest that you create a new table with the one field that you don't usually select with a key to the original table and remove the field from the original table.
Join the tables when that extra field is actually required. My main problem is the many columns I get when joining tables. While this is not the answer to your question how to select all but certain columns from one tableI think it is worth mentioning that you can specify table. The result is all the columns from the users table, and two additional columns which were joined from the meta table.
It is good practice to specify the columns that you are querying even if you query all the columns. So I would suggest you write the name of each column in the statement excluding the one you don't want. I liked the answer from Mahomedalid besides this fact informed in comment from Bill Karwin. The possible problem raised by Jan Koritak is true I faced that but I have found a trick for that and just want to share it here for anyone facing the issue.
I agree with the "simple" solution of listing all the columns, but this can be burdensome, and typos can cause lots of wasted time. I use a function "getTableColumns" to retrieve the names of my columns suitable for pasting into a query. Then all I need to do is to delete those I don't want.
Else, put the huge data in another table. If I were you I would use another language such as PHP to generate a list of columns you want to get, store it as a string and then use that to generate the SQL. So how it works is that you enter the table, then a column you don't want or as in an array: array "id","name","whatevercolumn".
I agree with Mahomedalid's answer, but I didn't want to do something like a prepared statement and I didn't want to type all the fields, so what I had was a silly solution. If it contains enormous amounts of text, xml or binary blobs, then take the time to select each column individually.
Your performance will suffer otherwise. Based on Mahomedalid answer, I have done some improvements to support "select all columns except some in mysql". This is a general solution as it extracts the column names from the information schema.
Here is an example from the Unix command line. You will really only need to extract the column names in this way only once to construct the column list excluded that column, and then just use the query you have constructed.Santhoshkumar KB. More actions. If you don't want to type, and I don't blame you, then there's a quick way.
Expand out object explorer until you can see the table. Expand that out as well. Click on "Columns" and drag that to the query window and you'll have a full list of all the columns in the table, comma delimited. Then you can remove the two that you don't want. Sakthivel Chidambaram.
Florian Reischl. If I need to write all the columns it will be confusing rather than confusing it will be difficult. If all you're trying to do is compare two tables, have you considered using the tablediff utility that comes with SQL?
If you use the -b flag and specify 0, it won't compare any of the LOB columns. It's a lot easier than writing custom code. You must be logged in to reply to this topic.
Login to reply. Post reply. March 3, at pm Hi, There is a table with 50 columns: I need to select 48 or 49 columns only. Is there any way to do this? Ex: select col1,col2, Gail Shaw. March 4, at am Yup, list all the column names as you've done in your example If you don't want to type, and I don't blame you, then there's a quick way. You already have the query you are looking for Then what else you need??
Thanks and sorry Flo. Thanks Flo and Gail, but the requirement is 1. Please let me know if this post is confusing, I will try to modify Thanks San.Writing out every every column name can quickly become tedious, especially if you happen to be dealing with tables that contain dozens of columns. What if we could select every column but one - selecting by exclusion rather than inclusion?
It can be done. In fact there are a couple of ways to do it - one simple, the other, a bit less so. These will be the focus of today's blog.
Selecting all except some columns in MySQL
The Sakila sample database 's film table contains the highest number of columns at thirteen. We can then replace the field to omit with an empty string! One small hurdle to overcome is that a MySQL query cannot accept dynamic column names. The solution is to employ a Prepared Statement. Here's the code that sets the sql variable, prepares the statement, and executes it:.Stihl 462 vs 500i
Inserting the column, table, and schema information into the query yields the results that we're after:. The main goal of database development and administration tools like Navicat is to increase productivity.
As such, Navicat is designed to make your job as quick and easy as possible. To that end, the SQL Editor helps you to code faster thanks to Code Completion and customizable Code Snippets that offer suggestions for keywords and strip the repetition from coding. And if that wasn't enough, Navicat also provides a useful tool called Query Builder for building queries visually. It allows you to create and edit queries with only a cursory knowledge of SQL. While the Query Builder is marketed predominantly to more novice coders, those more proficient in SQL can still benefit from the Query Builder for certain tasks.
One such tasks is that of choosing columns. In the Query Builder, there is a checkbox next to the table name to select all of its columns. In today's blog, we learned a couple of techniques to select every column in a table but one or two.
Combine Information from Multiple MySQL Tables with JOIN
You can try it for 14 days completely free of charge for evaluation purposes!Posted by: admin October 29, Leave a comment. Is there a simple way to do this?
In mysql definitions manual there is no such thing.Area of polygon calculator
But if you have a really big number of columns col1…, colthe following can be useful:. If you are looking to exclude the value of a field, e. However, if you want a lot of columns, then you might just want to do a:. Join the tables when that extra field is actually required. While trying the solutions by Mahomedalid and Junaid I found a problem. So thought of sharing it.
If the column name is having spaces or hyphens like check-in then the query will fail. The simple workaround is to use backtick around column names. The modified query is below. My main problem is the many columns I get when joining tables. While this is not the answer to your question how to select all but certain columns from one tableI think it is worth mentioning that you can specify table.
The result is all the columns from the users table, and two additional columns which were joined from the meta table. It is good practice to specify the columns that you are querying even if you query all the columns. I liked the answer from Mahomedalid besides this fact informed in comment from Bill Karwin. The possible problem raised by Jan Koritak is true I faced that but I have found a trick for that and just want to share it here for anyone facing the issue.
Else, put the huge data in another table. If I were you I would use another language such as PHP to generate a list of columns you want to get, store it as a string and then use that to generate the SQL. If it contains enormous amounts of text, xml or binary blobs, then take the time to select each column individually. Your performance will suffer otherwise. This is a general solution as it extracts the column names from the information schema.
Here is an example from the Unix command line. You will really only need to extract the column names in this way only once to construct the column list excluded that column, and then just use the query you have constructed. I would like to add another point of view in order to solve this problem, specially if you have a small number of columns to remove.
You could use a DB tool like MySQL Workbench in order to generate the select statement for you, so you just have to manually remove those columns for the generated statement and copy it to your SQL script. So What I had was a silly solution. Im pretty late at throing out an answer for this, put this is the way i have always done it and frankly, its times better and neater than the best answer, i only hope someone will see it. And find it useful.Need support for your remote team?
Check out our new promo! Select all Open in new window. IT issues often require a personalized solution. Why EE? Get Access. Log In. Web Dev. NET App Servers. We help IT Professionals succeed at work. Medium Priority. Last Modified: Start Free Trial. View Solutions Only. Top Expert This award recognizes someone who has achieved high tech and professional accomplishments as an expert in a specific topic. Commented: There is no syntax for that.Son cubano menu
Not the solution you were looking for? Getting a personalized solution is easy. Ask the Experts. Author Commented: I like the idea of using a temporary table however the code provided for the temporary table does not work. Are you open to using a stored procedure? I think it can be done using dynamically formed SQL within a stored procedure, but I won't put effort into it if this is not an option for you. Works with me. I again tried it.
Yeah that should work, but how big is the data and how frequent will this be done? I'm under the impression this will be done frequently so copying the full table and dropping the column will be quite inefficient. Kevin Cross Chief Technology Officer.
Experts with Gold status have received one of our highest-level Expert Awards, which recognize experts for their valuable contributions. Most Valuable Expert This award recognizes tech experts who passionately share their knowledge with the community and go the extra mile with helpful contributions. Silly question, but this is MySQL, correct? Is it not possible to create a view one time in which you explicitly list the columns you want except the one?
Multimatic Technical Services Manager. Needed to do similar before and used the schema. Originally done on business layer and built dynamic SQL there, but can be done easily in stored proc using prepared statement. Multimatic's solution was what I had in mind when I said use a stored procedure.
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