Question

Structure of the CUSTOMERS table

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Which of the following commands will increase the size of the CITY column in the CUSTOMERS table from 12 to 20 and increase size of the LASTNAME column from 10 to 14?

Answer 1

To increase the size of columns in a table, the ALTER TABLE command is used. An example command to increase the CITY column to 20 characters and the LASTNAME column to 14 characters would be `ALTER TABLE CUSTOMERS MODIFY (CITY VARCHAR2(20), LASTNAME VARCHAR2(14));`.

Step-by-step explanation:

To increase the size of the CITY column in the CUSTOMERS table from 12 to 20 and the size of the LASTNAME column from 10 to 14, one would typically use the ALTER TABLE command in SQL. The specific syntax can vary depending on the database system being used, but a general example of such a command would be:

ALTER TABLE CUSTOMERS
MODIFY (CITY VARCHAR2(20), LASTNAME VARCHAR2(14));

This command modifies the structure of the CUSTOMERS table by altering the size of the specified columns. It's important to ensure that the database user has the necessary permissions to perform this operation and that the operation does not inadvertently truncate any existing data in the table that exceeds the new column size constraints.