can we delete Only information from a column in SQL?

Question

if yes, plz tell me that query........

Answer 1

UPDATE TableName SET ColumnName = NULL



If you are deleting the column values from every record then you do not need a where clause.

Answer 2

Sql Delete Column Data

Answer 3

Besides the UPDATE query already mentioned, it may be possible (depending on your DBMS) to remove the column altogether. However, this is usually a 2 or more step process:



1) If there is an index that includes the column in question, use DROP INDEX to delete it.

2) If the column currently defined as NOT NULL, use ALTER TABLE to make nullable.

3) Use UPDATE as mentioned already to null the values.

4) USE ALTER TABLE to drop the column.

Answer 4

I assume you want to delete all values in a column for all records in a table,



SQL="Update (TABLE) Set (COLUMN) = '' Where (COLUMN)= '*'";

or

SQL="Update (TABLE) Set (COLUMN) = null Where (COLUMN)= '*'";

Answer 5

You could create the new table and then SELECT...INTO any existing data in the old one into the new table. Otherwise you could try ALTER TABLE tablename ADD columnname columntype For example: ALTER TABLE pets ADD owner varchar(30) To delete an entire table along with its data and indexes, you can use DROP TABLE tablename Hope this helps!

Answer 6

are you trying to delete a certain record from a certain column? if so, look for a google tutorial about deleting records