Αποτελέσματα Αναζήτησης
21 Νοε 2016 · ALTER TABLE { ALTER COLUMN column_name | ADD | DROP } According to Transact-SQL Syntax Conventions (Transact-SQL) the | (vertical bar) Separates syntax items enclosed in brackets or braces.
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);
To add a column in a table, use the following syntax: ALTER TABLE table_name. ADD column_name datatype; The following SQL adds an "Email" column to the "Customers" table: Example. ALTER TABLE Customers. ADD Email varchar (255); ALTER TABLE - DROP COLUMN.
Dropping multiple columns using alter table. ALTER TABLE JOBS_Temp DROP (BONUS, COMMISSION)
ALTER TABLE table_name DROP COLUMN column_name; Code language: SQL (Structured Query Language) (sql) This statement deletes the column from the table structure and also the data stored in that column.
On the DROP clause, use GROUP log_group syntax to drop a named supplemental log group and use the supplemental_id_key_clause to drop a system-generated log group. The supplemental_log_grp_clause and the supplemental_id_key_clause have the same semantics in CREATE TABLE and ALTER TABLE statements.
