cyclopedia anatomicae

rows Select * from table LIMIT; # return the first five rows 1. when the offset value is small.Select * from yanxue8_visit limit 10, 10 Run multiple times and keep the time between 0.0004 and 0.0005Select * From yanxue8_visit Where vid> = (Select vid From yanxue8_visit Order By vid limit 10, 1) Limit 10 Run multiple times, and the time is kept between 0.0005-0.0006, mainly 0.0006Conclusion: When the offset is small, it is better to use limit directly. This is obviously the cause of subquery.

directly. This is obviously the cause of subquery. 2. When the offset value is large Select * from yanxue8_visit limit, 10 Run multiple times and keep the time at around 0.0187 Select * From yanxue8_visit Where vid> = ( Select vid From yanxue8_visit Order By vid limit, 1 ) Limit 10 Run multiple times, with a time of around 0.0061, only 1/3 of the former. It can be predicted that the larger the offset, the higher the latter. Attached Original: Select * from table LIMIT 5, 10; # return da

yanxue8_visit Order By vid limit 10000,1 ) limit 10 Run multiple times, with a time of around 0.0061, only 1/3 of the former. It can be predicted that the larger the offset, the higher the latter. Attached Original: Select * from table LIMIT 5, 10; # return data in rows 6-15 Select * from table LIMIT 5; # Return the first five rows Select * from table LIMIT; # Return the first five rows Performance Optimization: Based on the high performance of Mysql limit in MySQL5.0, I have a new under

SQL limit to implement TENS data volume paging SELECT * FROM Table LIMIT 5, 10; #返回第6-15 rows of dataSELECT * FROM table LIMIT 5; #返回前5行SELECT * FROM table LIMIT 0, 5; #返回前5行 Performance optimization: Based on the high performance of limit in MySQL5.0, I have a new understanding of data paging. 1.Select * FROM Cyclopedia Where id>= (Select Max (ID) from (Select ID from Cyclopedia order by ID lim

specified, it indicates that the maximum number of record rows is returned:Mysql> SELECT * FROM table LIMIT 5; // retrieve the first five record rows // In other words, LIMIT n is equivalent to LIMIT 0, n. Note the differences between limit 10 and limit 9 and 1: for example, 1.Select * From cyclopedia Where ID> = (Select Max (ID) From (Select ID From cyclopedia Order By ID limit 90001) As tmp) Limit 100; 2

records FROM 6 to 15 rows.// To retrieve all record rows from an offset to the end of the record set, you can specify the second parameter-1:Mysql> SELECT * FROM table LIMIT 95,-1; // retrieves 96-last Records.// If only one parameter is specified, it indicates the maximum number of record rows returned:Mysql> SELECT * FROM table LIMIT 5; // retrieve the first five record rows// In other words, LIMIT n is equivalent to LIMIT 0, n.Note the differences between limit 10 and limit 9 and 1:For examp

Select * from Table limit 5, 10; # return data in rows 6-15 Select * from Table limit 5; # Return the first five rows Select * from Table limit; # Return the first five rows Performance Optimization:Based on the high performance of limit in mysql5.0, I have a new understanding of data paging. 1.Select * From Cyclopedia where ID> = (Select max (ID) from (Select ID from Cyclopedia order by ID limit 90001) As

is better to use limit directly. This is obviously the cause of subquery.2. When the offset value is large.Select * From yanxue8_visit limit, 10Run multiple times and keep the time at around 0.0187Select * From yanxue8_visit where vid> = (Select vid from yanxue8_visit order by VID limit, 1) Limit 10Run multiple times, with a time of around 0.0061, only 1/3 of the former. It can be predicted that the larger the offset, the higher the latter. Performance Optimization: Based on the high perform

100 data in the class table, the return is 0 start 90 data, i.e. 0 to (100-10)Third, Performance3.1, basic 1, offset is relatively small time. SELECT * from Yanxue8_visit limit 10, 10 runs multiple times, time remains between 0.0004-0.0005 select*from yanxue8_visit Where vid >= ( Selectvidfrom yanxue8_visit Order by vid limit 10,1) limit 10 runs multiple times, The time remains between 0.0005 and 0.0006, mostly 0.0006 conclusions: When offset offsets are smaller, direct use of limit is preferre

that the maximum number of record rows is returned:Mysql> select * from Table limit 5; // retrieve the first five record rows // In other words, limit N is equivalent to limit 0, N. Note the differences between limit 10 and limit 9 and 1: for example, 1.Select * From Cyclopedia where ID> = (Select max (ID) from (Select ID from Cyclopedia order by ID limit 90001) As TMP) Limit 100; 2.Select * From

returned:Mysql> SELECT * from table LIMIT 5; Retrieve the first 5 rows of recordsIn other words, LIMIT n is equivalent to LIMIT 0,n.Note the differences between limit 10 and limit 9,1:For example:1. Copy Code code as follows: Select * FROM Cyclopedia Where id>= ( Select Max (ID) from ( Select ID from Cyclopedia order by ID limit 90001 ) as TMP ) limit 100; 2. Copy Co

efficient paging!In this example, I reflect on a point: for large systems, PHP must not use the framework, especially that even SQL statements can not see the framework! Because the beginning of my lightweight framework almost crashed! Only for the rapid development of small applications, for Erp,oa, large web sites, data layer including logic layer of things can not use the framework. If the programmer loses control of the SQL statement, the risk of the project will increase exponentially! Esp

Cyclopedia Where ID>= ( Select Max (ID) from ( Select ID from Cyclopedia Order by ID limit 90001 ) as TMP ) limit 100; Select * FROM Cyclopedia Where ID>= ( Select Max (ID) from ( Select ID from Cyclopedia Order by ID limit 90000,1 ) as TMP ) limit 100; The same is taken 90,00

SELECT * FROM Yanxue8_visit limit 10000,10 Run multiple times and keep time at around 0.0187 Select * from Yanxue8_visit Where vid >= ( Select vid from Yanxue8_visit Order by vid limit 10000,1 ) Limit 10 Run several times, the time remains around 0.0061, only the former 1/3. You can expect the larger the offset, the better the latter.Attached Original:SELECT * FROM Table LIMIT 5, 10; #返回第6-15 rows of dataSELECT * FROM table LIMIT 5; #返回前5行SELECT * FROM table

best performance. The performance difference caused by an index can be thousands of thousand! Performance optimization:Based on the high performance of limit in MySQL5.0, I have a new understanding of data paging. 1.Select * FROM Cyclopedia Where id>= (Select Max (ID) from (Select ID from Cyclopedia Order by ID limit 90001) as TMP) limit 100; 2.Select * FROM Cyclopedia