What are the usages of limit in MySQL (recommended)

SELECT * FROM table name limit m,n;
SELECT * FROM table LIMIT [offset,] rows;

1. m means starting the search from the m+1th row, and n means retrieving n pieces of data. (m can be set to 0)

For example: SELECT * FROM 表名limit 6,5;

Means: starting from the 7th record line, take out 5 data

2. It is worth noting that n can be set to -1. When n is -1, it means starting the search from row m+1 until the last piece of data is retrieved.

For example: SELECT * FROM 表名limit 6,-1;

It means: take out all the data after the 6th record line.

3. If only m is given, it means taking out a total of m records starting from the first record line.

For example: SELECT * FROM 表名limit 6;

Means: Get the first 6 rows.

4. Select the corresponding statement according to the amount of data:

a.Offset is relatively small:

SELECT * FROM aff limit 10,10

After multiple runs, the time remained between 0.0004-0.0005

SELECT * FROM aff Where vid >=(
SELECT vid From aff Order By vid limit 10,1
) limit 10

After multiple runs, the time remained between 0.0005-0.0006, mainly 0.0006

Conclusion: When the offset is small, it is better to use limit directly. This display is the reason for the subquery.

b. When the offset is large.

SELECT * FROM aff limit 10000,10

After multiple runs, the time remains around 0.0187

SELECT * FROM aff Where vid >=(
SELECT vid FROM aff Order By vid limit 10000,1
) limit 10

After multiple runs, the time remained at around 0.0061, which is only 1/3 of the former.

Conclusion: The larger the offset, the better the latter.

Summarize

The above is the usage of limit in MySQL that I introduced to you. I hope it will be helpful to you. If you have any questions, please leave me a message and I will reply to you in time. I would also like to thank everyone for their support of the 123WORDPRESS.COM website!