Modifying Data

Learn how to modify database data using the SQL UPDATE and DELETE statements. This lesson helps you correct errors by updating specific records and remove incorrect entries with precision. Understand the syntax, use the WHERE clause effectively to target records, and verify changes to maintain accurate data management.

We'll cover the following...

The UPDATE statement
The DELETE FROM statement

Sometimes, data is inserted erroneously in the database. This can involve two types of mistakes: inserting a wrong value against a certain field or mistakenly inserting an entire record. Alongside rectifying such inconsistencies, we also need ongoing management and synchronization of data, such as ensuring that a person’s address remains current and accurate. Situations like these require making alterations to the data. For this purpose, we employ the UPDATE and DELETE FROM statements in SQL as and when needed. These are explained below:

The `UPDATE` statement

Consider a scenario where an error exists in one of the records, necessitating correction. For example, let’s consider a sale with SaleID 3, ...

1.Introduction to SQL

2.SQL SELECT

3.SQL Queries: SELECT, WHERE, AND, OR, NOT, and Strings

4.SQL ORDER BY, Aggregate functions, and GROUP BY

5.SQL CREATE, DESCRIBE, INSERT INTO, UPDATE and DELETE Tables

6.SQL Alter Table and Aliases

7.Data Redundancy

8.SQL Joins and Subqueries

9.Wrap Up

Modifying Data

The `UPDATE` statement

Modifying Data

The UPDATE statement

The `UPDATE` statement