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Description: This article mainly describes the MySQL DML lock phenomenon. It shows that the lock phenomenon generated by update and delete is the same.

Table information:

Case 1: There is a primary key, insert only locks the data of the current row

Issue 1:

Issue 2:

So there's no lock problem.

Case 2: There is a primary key, update the last row of the ordinary column

Issue 1:

Issue 2:

Update updates the last line, locking infinity.

Case 3: There is a primary key, update ordinary columns and multiple rows

Issue 1:

Issue 2:

Update multiline range locks lock only the updated line.

Case 4: There is a primary key, update the last column of the primary key

Issue 1:

Issue 2:

update updates according to the primary key, there will be no infinite locks

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