How Can I Efficiently Update Multiple Records Simultaneously in SQL?

Updating Multiple Records Simultaneously in SQL

When dealing with tables containing configuration settings or other related data, it often becomes necessary to update multiple records simultaneously. This task can be efficiently accomplished utilizing SQL's advanced update capabilities.

In the scenario presented, you have a table named config with two columns: config_name and config_value. Your initial attempt to update multiple records using a naïve approach yielded an error. To address this, consider employing one of the following techniques:

Multi-Table Update Syntax:

This method involves joining the target table multiple times to create a temporary multi-table dataset. You can then update multiple records by referring to each table explicitly in the SET clause:

UPDATE config t1 JOIN config t2
    ON t1.config_name = 'name1' AND t2.config_name = 'name2'
   SET t1.config_value = 'value',
       t2.config_value = 'value2';

Conditional Update:

Alternatively, you can use a conditional update to update multiple records based on different criteria. In this case, you would use the CASE statement within the SET clause to specify the desired value for each config_name:

UPDATE config
   SET config_value = CASE config_name 
                      WHEN 'name1' THEN 'value' 
                      WHEN 'name2' THEN 'value2' 
                      ELSE config_value
                      END
 WHERE config_name IN('name1', 'name2');

Both approaches effectively update multiple records in a single query, allowing for efficient data management in your SQL applications.

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