How can I increase the length of a table column in PL/SQL?

To increase the length of a table column in PL/SQL, you can achieve this by using the ALTER TABLE statement. Here is an example:

ALTER TABLE 表名
MODIFY 列名 数据类型(新长度);

For example, if you want to increase the length of a column in the table to 50, you can use the following statement:

ALTER TABLE employees
MODIFY last_name VARCHAR2(50);

Please ensure data backup before executing the ALTER TABLE statement and make sure that the modified length will not lead to data loss or truncation.