As Internet applications become more and more widespread, the importance of databases has been further recognized. With the increase in database applications, related programming skills have also been further improved. In PHP programming, optimizing and tuning database queries and data saving is very important because they directly affect page load time and server performance. In this article, we will introduce some common database design and optimization techniques in PHP programming.
1. Table design
The table is an important part of the database. A good table design can improve the efficiency of database queries and reduce the space for data storage. The following are some tips on how to design a good table:
1. Choose the correct data type
When selecting a data type, you should try to choose the smallest data type to reduce storage space occupied. For example, you can choose the INT type to store numbers, the VARCHAR type to store strings, and so on. Additionally, appropriate data types should be chosen to match the nature of the data.
2. Appropriate keywords
Columns that help query and sort should be defined as indexes. For long text type columns, you can use the FULLTEXT index to improve the performance of full-text search.
3. Normalization
Normalization can make the table structure more concise and easier to maintain. During the design process, duplicate data should be separated into other tables as much as possible to avoid data redundancy and data inconsistent.
2. Query Optimization
1. Choose the appropriate SQL statement
Different SQL statements have different execution times, so you need to choose the appropriate SQL statement according to your needs. Try to choose a SELECT statement with a short running time and reduce operations such as JOIN operations and subqueries.
2. Use appropriate indexes
Indexes can greatly improve the efficiency of queries. Indexes should be created for frequently queried columns. In MySQL, you can use the EXPLAIN statement to analyze query statements, troubleshoot slow query problems and select appropriate indexes.
3. Avoid executing queries in a loop
Executing query operations in a loop will occupy a large amount of server resources, and this operation should be avoided as much as possible. Data merging techniques such as JOIN and GROUP BY can be used to reduce the number of queries.
3. Caching skills
In MySQL, caching can increase the speed of queries and reduce the number of database operations. The following are some tips on how to use caching technology:
1. Use the built-in caching function
MySQL has a built-in query caching function that can cache the results of the SELECT statement. Caching can be enabled by setting configuration parameters.
2. Use Memcache to cache
Memcache is a cache technology that can be used to cache SQL query results, Web pages, Session and other data. Can provide more efficient caching operations than MySQL's built-in cache.
3. Use APC accelerator
APC is a caching extension for PHP that can cache PHP scripts and database query results. It can cache compiled scripts and store them in memory to improve the execution efficiency of PHP scripts.
4. Code Optimization
1. Reduce external requests
Reducing requests for external resources can improve the loading speed of the page. External requests can be reduced using appropriate CDN services, caching technology and compression technology.
2. Use PDO and prepared statements
Using PDO and prepared statements can avoid SQL injection attacks. PDO also provides many advanced features, such as transactions and batch insert operations.
3. Use caching technology
Using caching technology can reduce the number of database operations and improve query efficiency. Technologies such as MySQL built-in cache, Memcache and APC accelerator can be used.
Summary:
The above are common database design and optimization techniques in PHP programming. In the actual programming process, appropriate technologies and optimization solutions should be selected based on specific scenarios and needs. In addition, attention should also be paid to the standardization and readability of the code, which helps code maintenance and reuse. Finally, some common mistakes should be avoided, such as SQL injection attacks, memory leaks, and deadlocks.
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