To this point, I’ve explained how to use SELECT to retrieve and analyze the data in tables. In this chapter, I’ll explain how to use SQL statements to modify table data:
The INSERT statement adds new rows to a table.
The UPDATE statement changes the values in a table’s existing rows.
The DELETE statement removes rows from a table.
These statements don’t return a result, but your DBMS normally will print a message indicating whether the statement ran successfully and, if so, the number of rows affected by the change. To see the actual effect the statement had on a table, type a SELECT statement such as SELECT * FROM table.
Unlike SELECT, which only accesses data, these statements change data, so ...