Adding a Column¶
Function¶
This statement is used to add one or more new columns to a table.
Syntax¶
ALTER TABLE [db_name.]table_name ADD COLUMNS (col_name1 col_type1 [COMMENT col_comment1], ...);
Keywords¶
ADD COLUMNS: columns to add
COMMENT: column description
Parameters¶
Parameter | Description |
|---|---|
db_name | Database name that contains letters, digits, and underscores (_). It cannot contain only digits or start with an underscore (_). |
table_name | Table name |
col_name | Column name |
col_type | Field type |
col_comment | Column description |
Precautions¶
Do not run this SQL statement concurrently. Otherwise, columns may be overwritten.
Example¶
ALTER TABLE t1 ADD COLUMNS (column2 int, column3 string);