Αποτελέσματα Αναζήτησης
20 Δεκ 2012 · Use ALTER TABLE with DROP COLUMN to drop a column from a table, and CHANGE or MODIFY to change a column. ALTER TABLE tbl_Country DROP COLUMN IsDeleted; ALTER TABLE tbl_Country MODIFY IsDeleted tinyint(1) NOT NULL; ALTER TABLE tbl_Country CHANGE IsDeleted IsDeleted tinyint(1) NOT NULL;
DROP COLUMN. The DROP COLUMN command is used to delete a column in an existing table. The following SQL deletes the "ContactName" column from the "Customers" table:
Oracle Drop Column using DROP COLUMN clause. To drop a column from a table physically, you use the following statement: ALTER TABLE table_name DROP COLUMN column_name; Code language: SQL (Structured Query Language) (sql) To drop multiple columns, you use the statement below:
To physically drop a column you can use one of the following syntaxes, depending on whether you wish to drop a single or multiple columns. alter table table_name drop column column_name; alter table table_name drop (column_name1, column_name2);
This statement works in MySQL and PostgreSQL. For Oracle and SQL Server, you use the following statement: ALTER TABLE persons DROP COLUMN date_of_birth, phone; Code language: SQL (Structured Query Language) (sql) In this tutorial, you have learned how to use the SQL DROP COLUMN statement to remove one or more columns from a table.
Examples showing how to drop a column from a table in PostgreSQL, MySQL, SQL Server, and Oracle.
Drop column in table Syntax. To DROP A COLUMN in an existing table, the Oracle ALTER TABLE syntax is: ALTER TABLE table_name DROP COLUMN column_name; Example. Let's look at an example that shows how to drop a column in an Oracle table using the ALTER TABLE statement. For example: ALTER TABLE customers DROP COLUMN customer_name;
