How Can I Update Multiple MySQL Rows with Different Values Using a Single Query?

Efficiently Updating Multiple MySQL Rows with Varied Values

This guide addresses the common challenge of updating multiple database rows with unique values using a single MySQL query. While several methods exist, this approach offers clarity and efficiency.

A Clearer Approach Using CASE Statements

The conventional method, often involving nested IF() statements, becomes cumbersome with multiple conditions. A superior alternative leverages the power of CASE statements:

<code class="language-sql">UPDATE table_users
SET cod_user = (CASE WHEN user_role = 'student' THEN '622057'
                     WHEN user_role = 'assistant' THEN '2913659'
                     WHEN user_role = 'admin' THEN '6160230'
                END),
    date = '12082014'
WHERE user_role IN ('student', 'assistant', 'admin') AND
      cod_office = '17389551';</code>

This streamlined query uses CASE to dynamically assign cod_user values based on user_role, while simultaneously setting date to a consistent value for all matching rows.

Key Considerations

• CASE Statements: These provide a concise way to handle multiple conditional assignments within a single query.
• WHERE Clause: This precisely targets rows for updating, ensuring only relevant records are modified.
• Data Integrity: For optimal data management, store dates using MySQL's native date/time data types.

This combined CASE and WHERE approach offers a structured and easily understandable solution for updating multiple rows with diverse values in MySQL.

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