First, give the solution directly:

Click a_ I, do not enter the size, directly click to execute

Analysis

When you use phpMyAdmin to create a database table, we usually need to set a primary key and let it grow by itself. But sometimes when you finish setting, you may find such an error:

1089 - Incorrect prefix key; the used key part isn’t a string, the 
used length is longer than the key part, or the storage engine doesn’t 
support unique prefix keys

The picture is shown as follows:

Fault analysis:

References

Preview SQL statement:

We found that there is indeed an additional 4 in primary key, so how to solve the problem
do you really need the command line to handle it?Of course not

Solution:

When setting self growth, we will see this interface:

Tips:
it is worth noting that this size is not a required value, but it is not very familiar with phpMyAdmin. It is easy to subconsciously set a value for the first time. Once it is set, the above error will appear
so the final solution is the size in the diagram. Here, we just need to leave the blank and click execute to save the table successfully