Why MySQL UPDATE Appears to Do Nothing and How to Fix It

Several developers have reported that an UPDATE statement in MySQL executes without errors but appears to leave the record unchanged.

The problematic SQL (shown in the original image) uses the AND keyword to separate column assignments.

Before execution the record looks like the first screenshot, and after execution the second screenshot shows that the data actually changed, contrary to the developer’s expectation.

Reviewing the MySQL documentation reveals that the SET clause of an UPDATE must list column_name = value pairs separated by commas, not by AND. The correct multi‑column update syntax is illustrated in the following image.

Re‑running the statement with commas instead of AND produces the expected result, as confirmed by the third screenshot.

Key Takeaway

When updating multiple columns in a single UPDATE statement, separate the assignments with commas rather than the AND keyword.

Postscript

Using AND creates a logical expression; for example, ('43212' AND owner_name='李四') evaluates to FALSE, which MySQL treats as 0. This explains why unexpected values such as owner_code=0 can appear.