Learning Linux Shell Scripting - Second Edition

Altering a table

If we want to modify a table's basic structure, such as, adding an extra column, then we need to use the Alter command. When we need to put more information related to table objective, using this command, we can add extra column. We can use this command to modify table as well as database also.

In the next script, we are going to alter the table. Create the script mysql_11.sh to alter the table definition:

#!/bin/bash 
mysql -u user1 -pTest623@! <<MY_QUERY 
use testdb; 
ALTER TABLE Authors 
ADD ADDRESS VARCHAR(25); 
MY_QUERY 

In this shell script, we have added a new field named ADDRESS using ALTER command.

Now save the program and run it as follows:

          $ chmod +x mysql_11.sh
          $ ./mysql_11.sh