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Editor to share with you whether there is a top query in the mysql database. I hope you will gain a lot after reading this article. Let's discuss it together.

Friends who are used to access mssql server, may be used to use mysql to query the first N records, the habit of using select top n form statements, to explain here, mysql does not have this syntax, mysql uses limit to achieve related functions, and the function is more powerful, GOOD. The following is a detailed explanation of the use of limit in mysql:

Syntax:

SELECT * FROM table LIMIT [offset,] rows | rows OFFSET offset

The LIMIT clause can be used to force the SELECT statement to return a specified number of records. LIMIT accepts one or two numeric parameters. Parameter must be an integer constant.

Given two parameters, the first parameter specifies the offset of the first returned record row, and the second parameter specifies the maximum number of record rows returned.

The offset of the initial record line is 0 (not 1): for compatibility with PostgreSQL, MySQL also supports syntax: LIMIT # OFFSET #.

Mysql > SELECT * FROM table LIMIT 510; / / retrieve record lines 6-15. Note that 10 is the offset.

/ / to retrieve all record rows from a certain offset to the end of the recordset, you can specify the second parameter as-1:

Mysql > SELECT * FROM table LIMIT 95 96-last; / / search the record line.

/ / if only one parameter is given, it represents the maximum number of record rows returned:

Mysql > SELECT * FROM table LIMIT 5; / / retrieve the first five rows of records / / that is, LIMIT n is equivalent to LIMIT 0J n.

If you want the last few pieces of data, you can add an extra order by id desc.

Mysql does not support the syntax of select top n, so you should replace it with this:

Select * from tablename order by orderfield desc/asc limit position, counter

Position indicates where to start the query, if it is 0, it starts from scratch, and counter indicates the number of queries.

Take the first 15 records:

Select * from tablename order by orderfield desc/asc limit 0pl 15

After reading this article, I believe you have a certain understanding of whether there is any top query in the mysql database. I would like to know more about it. Welcome to follow the industry information channel. Thank you for your reading!

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