MySQL is the second most popular open source relational database management system in the world. It is used worldwide with continuous and rapid performance, high reliability and ease of use. This article provides several MySQL best practices. Practice SQL with them, set up some SQL exercises by yourself, learn SQL restrictions, online sql exercises, and the most common SQL exercises. It is helpful to understand line number SQL, SQL top, MySQL limit offset and SQL online practice. If you use rich, useful, and responsive interactive tables and charts to find a cool, simple way to display a large number of rows and columns to WordPress site visitors, you can use it with the wpdatatables plug-in, the price, and all the features provided here. The
1. always use the appropriate data type. One of the most important MySQL best practices is to use data types according to the characteristics of the data. Unrelated data types may take up more space or cause errors. For example, if you use varchar (20) instead of the datetime data type to store datetime values, the datetime related calculations will have errors. In addition, invalid data may be stored. 2. compared with varchar (1), varchar (1) using char (1) uses additional bytes to store information. Therefore, if a single character is specified as a string, char (1) is recommended. The
3. use the char data type to store only fixed length data. For example, if the data length is less than 1000, using char (1000) instead of varchar (1000) will occupy more space. 4. do not use the regional date format. When using datetime or date data types, always use the yyy-mm-dd date format or ISO date format that is appropriate for the SQL Engine. The format of dd-mm-yyy or mm-dd-yyy is stored incorrectly. 5. the index key column query is best to return results as soon as possible, so the columns used in the join section must be indexed. The
If you use an update statement that contains multiple tables, you must index all the columns used to join the tables. 6. do not use functions in columns of the index Because the index loses its purpose. For example, suppose the first two characters of the customer code try to import AK data. Write: select columns from table where customer\u code like \
What’s the matter. The first example uses indexes, so response times are faster. 7. use the MySQL best practices list according to SQL select* only when necessary. Do not blindly use select* in your code. If there are many columns in the table, all are returned. This delays response time, especially when sending results to front-end applications. Instead, enter the actual column name explicitly. Note: all select statements require a where section. 8. use the order by section only if necessary. To display the results in the front-end application, let the result set order. Performing this operation in SQL may reduce response time in a multi-user environment. The
9. if the developed application (such as search engine) reads data more frequently than the appropriate database engine, select MyISAM storage engine. Selecting the wrong storage engine will affect performance. 10. in order to confirm whether the exists section usage data exists when necessary, e has a faster response time
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