Python MySQLLesson 121Free preview

MySQL Update

This lesson is part of Python · All levels

Summary

This lesson explains how to update existing data in a MySQL table with the UPDATE command. The SET clause specifies the column with its new value, whereas the WHERE restricts any line that can be changed. Like other written operations, changes are only stored after the conn.commit() is called.

Key points

Basic format: UPDATE the name_table of the SET column = the WHERE value of the condition.
Without WHERE, the entire row on the table will be updated to the same value.
The value should be given as a parameter %s for the security of SQL injection.
Cursor.rowcount shows how many lines have actually changed.
Expressions can use long values, for example SET price = price * 1.1 for a 10 percent increase.

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