Compare select * and select all fields to write speed examples

From a very early age, I heard the teacher say that select * from table is much slower than select a,b,c,d from table. Never tested in 3 years. I'll take a test today if I have nothing to do. I don't know if something unexpected happens. I'll be shocked if I take the test.

Of course the following is purely a test and has not been applied to actual projects. If you have any comments or suggestions, please let me know.

Number of times	*No. query	Field query
First Time
Second Time
the third time

##The test code is as follows:

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