Learn in the textbookBasics of Data Operations (Insert/Update and the Relational Operations for Retrieval)
DefinitionUpdate (更新) is the operation that replaces column values in a row already in the table with new values.
ExplanationIn SQL, the UPDATE statement names the columns to rewrite and their new values, and the condition in the WHERE clause narrows down the target rows. Run it without a condition and the specified columns change in every row of the table.
AnalogyLike erasing and rewriting just the phone number of a contact whose number has changed.
Memory hookThe word update is built from up and date, which fits an operation that brings values up to date.