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I would like to write a single SQL command word to drop several columns from a single table in one
ALTER Desk
statement.Last updated on March 3rd, 2019 at 06:16 pm-You Add a new column using the ALTER TABLE ADD COLUMN statement in Oracle The table must be contained in your schema To alter a table, or you should either have ALTER object privilege for the table or the ALTER ANY TABLE system privilege.
From MSDN's i9000 ALTER Desk paperwork.
Specifies that constraintname or columnname is definitely removed from the table. DROP Line is not really allowed if the compatibility level is definitely 65 or earlier. Several columns and restrictions can become outlined.
It states that mutliple columns can be outlined in the the statement but the format doesn'testosterone levels display an optional comma or anything that would even touch at the syntax.
How should I write my SQL to drop multiple columns in one declaration (if possible)?
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12 Solutions
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Summarizing
Oracle:
Master of science SQL:
MySql:
Be conscious
Fall COLUMN does not psychologically remove the data for some DBMS. Elizabeth.gary the gadget guy. for Master of science SQL. For fixed length sorts (int, numeric, drift, datetime, uniqueidentifier etc) the room is ingested even for information added after the columns had been fallen. To get rid of the lost space do ALTER TABLE. REBUILD.
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Be aware that DROP COLUMN will not in physical form get rid of the data, and for fixed length sorts (int, numeric, drift, datetime, uniqueidentifier etc) the area is ingested also for information added after the columns were fallen. To get rid of the wasted space perform
Remus RusanuRemus RusanuALTER TABLE. REBUILD
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This may be past due, but posting it for the brand-new users going to this query.To drop several columns actual syntax is definitely
Therefore for every column you need to specify 'drop column' in Mysql 5.0.45.
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The Syntax as given by Microsoft for the shedding a column component of an ALTER declaration will be this
See that the ,.in seems after both the column title and at the end of the whole drop clause. What this indicates can be that there are usually two methods to remove several columns. You can possibly perform this:
or this
This 2nd syntax is helpful if you desire to combine the drop of a column with losing a constraint:
When decreasing columns SQL Sever does not claim back the room used up by the columns lowered. For data sorts that are saved inline in the rows (int for example) it may even take up room on the new rows added after the alter statement. To obtain around this you need to make a clustered index on the table or improve the clustered catalog if it currently has one. Repairing the catalog can become carried out with a REBUILD control after adjusting the desk. But become warned this can be sluggish on really big dining tables. For example:
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For MySQL (ver 5.6), you cannot do multiple column drop with one one
drop
-declaration but instead multipledrop
-claims:BTW,
Patrick Kostjensdrop lt;colnamegt;
is definitely shorthanded fordrop column lt;colnamegt;
as you can observe fromdrop d3
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CSYCSY
If it will be just solitary column to delete the below format works
ALTER TABLE tablename DROP COLUMN column1;
For removing several columns, using the
DROP COLUMN
doesnot function, the below syntax worksALTER TABLE tablename DROP (column1, column2, column3.);
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this question will alter the multiple column check it.
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Ratan NahakRatan Nahak
for MySQL DB.
Or you can add some column while altering in the same collection:
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