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MySQL dynamically update columns using INNER JOIN method

Posted on 2025-04-19
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How to Dynamically Update Columns in MySQL Using INNER JOIN?

MySQL dynamically updates the associated table column data

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This article describes how to dynamically update columns in target tables using INNER JOIN in MySQL. Our goal is to update the value of the corresponding column in the source table (tableA) to the column in the target table (tableB) based on the shared name attribute.

can be implemented using the following UPDATE statement:

UPDATE tableB
INNER JOIN tableA ON tableB.name = tableA.name
SET tableB.value = tableA.value
WHERE tableA.name = 'Joe';

Through the INNER JOIN clause, we establish the relationship between two tables based on the name attribute, ensuring that only matching records are updated.

In addition to basic update operations, the value in tableB.value can also be dynamically modified according to the conditions in tableA.value. For example:

UPDATE tableB
INNER JOIN tableA ON tableB.name = tableA.name
SET tableB.value = IF(tableA.value > 0, tableA.value, tableB.value)
WHERE tableA.name = 'Joe';

This statement only updates the value of tableA.value to the tableB.value column when tableA.value is greater than 0. Otherwise, it retains the original value in the tableB.value column. By combining such conditional logic, more complex data operation tasks can be achieved.

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