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The RENAME COLUMN clause is an option on the ALTER TABLE statement. You can rename an existing column in a base table to a new name without losing stored data or affecting any privileges or label-based access control (LBAC) policies that are associated with the table.
1) Modifying the length & data type of column examples. The following example uses the ALTER TABLE ALTER COLUMN statement to change the data type of the created_date column from DATE to TIMESTAMP: ALTER TABLE orders. ALTER COLUMN created_date. SET DATA TYPE TIMESTAMP;
30 Σεπ 2016 · ALTER TABLE TEST_PROJECT2 MODIFY proj_name VARCHAR2(300); You only need to add parenthesis if you need to alter more than one column at once, such as: ALTER TABLE TEST_PROJECT2 MODIFY (proj_name VARCHAR2(400), proj_desc VARCHAR2(400));
To modify the length and type of a column of an existing table using the command line, enter: ALTER TABLE table_name ALTER COLUMN column_namemodification_type. For example, to increase a column up to 4000 characters, use something similar to the following: ALTER TABLE t1 ALTER COLUMN colnam1 SET DATA TYPE VARCHAR (4000)
Use the ALTER TABLE statement to drop columns, or change their types and attributes. For example, you can increase the length of an existing VARCHAR or VARGRAPHIC column. The number of characters might increase up to a value dependent on the page size used.
To modify a column of a table, you need to specify the column name, table name, and action that you want to perform. Oracle allows you to perform many actions but the following are the main ones: Modify the column’s visibility. Allow or not allow null values. Shorten or widen the size of the column. Change the default value of a column.
Introduction to Db2 RENAME TABLE statement. To change the name of an existing table to a new one, you use the RENAME TABLE statement. Here is the syntax of the RENAME TABLE statement: RENAME TABLE table_name TO new_table_name; Code language: SQL (Structured Query Language) (sql) In this syntax: First, specify the name of the table to which you ...
