Author Archives: user

Khóa học miễn phí MySQL – Find Duplicate Records nhận dự án làm có lương

MySQL – Find Duplicate Records Table of content Duplicate records in a table decrease the efficiency of a MySQL database (by increasing the execution time, using unnecessary space, etc.). Thus, locating duplicates becomes necessary to efficiently use the database. We can, however, also prevent users from entering duplicate values into a table, by adding constraints […]

Khóa học miễn phí MySQL – Standard Deviation nhận dự án làm có lương

MySQL – Standard Deviation Table of content MySQL Standard Deviation Functions are mathematical functions that are used to calculate the variation or dispertion between values in a dataset. There are two types of standard deviations in MySQL, they are population standard deviation and sample standard deviation. Popular standard deviation The “population standard deviation” is the […]