Avoid N 1 query problems, reduce the number of database queries by loading associated data in advance; 2. Select only the required fields to avoid loading complete entities to save memory and bandwidth; 3. Use cache strategies reasonably, such as Doctrine's secondary cache or Redis cache high-frequency query results; 4. Optimize the entity life cycle and call clear() regularly to free up memory to prevent memory overflow; 5. Ensure that the database index exists and analyze the generated SQL statements to avoid inefficient queries; 6. Disable automatic change tracking in scenarios where changes are not required, and use arrays or lightweight modes to improve performance. Correct use of ORM requires combining SQL monitoring, caching, batch processing and appropriate optimization to ensure application performance while maintaining development efficiency.

ReadonlypropertiesinPHP8.2canonlybeassignedonceintheconstructororatdeclarationandcannotbemodifiedafterward,enforcingimmutabilityatthelanguagelevel.2.Toachievedeepimmutability,wrapmutabletypeslikearraysinArrayObjectorusecustomimmutablecollectionssucha

Laravel supports the use of native SQL queries, but parameter binding should be preferred to ensure safety; 1. Use DB::select() to execute SELECT queries with parameter binding to prevent SQL injection; 2. Use DB::update() to perform UPDATE operations and return the number of rows affected; 3. Use DB::insert() to insert data; 4. Use DB::delete() to delete data; 5. Use DB::statement() to execute SQL statements without result sets such as CREATE, ALTER, etc.; 6. It is recommended to use whereRaw, selectRaw and other methods in QueryBuilder to combine native expressions to improve security

Go generics are supported since 1.18 and are used to write generic code for type-safe. 1. The generic function PrintSlice[Tany](s[]T) can print slices of any type, such as []int or []string. 2. Through type constraint Number limits T to numeric types such as int and float, Sum[TNumber](slice[]T)T safe summation is realized. 3. The generic structure typeBox[Tany]struct{ValueT} can encapsulate any type value and be used with the NewBox[Tany](vT)*Box[T] constructor. 4. Add Set(vT) and Get()T methods to Box[T] without

table-layout:fixed will force the table column width to be determined by the cell width of the first row to avoid the content affecting the layout. 1. Set table-layout:fixed and specify the table width; 2. Set the specific column width ratio for the first row th/td; 3. Use white-space:nowrap, overflow:hidden and text-overflow:ellipsis to control text overflow; 4. Applicable to background management, data reports and other scenarios that require stable layout and high-performance rendering, which can effectively prevent layout jitter and improve rendering efficiency.

Use JUnit5 and Mockito to effectively isolate dependencies for unit testing. 1. Create a mock object through @Mock, @InjectMocks inject the tested instance, @ExtendWith enables Mockito extension; 2. Use when().thenReturn() to define the simulation behavior, verify() to verify the number of method calls and parameters; 3. Can simulate exception scenarios and verify error handling; 4. Recommend constructor injection, avoid over-simulation, and maintain test atomicity; 5. Use assertAll() to merge assertions, and @Nested organizes the test scenarios to improve test maintainability and reliability.

Choosetheappropriateindextypebasedonusecase,suchassinglefield,compound,multikey,text,geospatial,orTTLindexes.2.ApplytheESRrulewhencreatingcompoundindexesbyorderingfieldsasequality,sort,thenrange.3.Designindexestosupportcoveredqueriesbyincludingallque

json.loads() is used to parse JSON strings into Python data structures. 1. The input must be a string wrapped in double quotes and the boolean value is true/false; 2. Supports automatic conversion of null→None, object→dict, array→list, etc.; 3. It is often used to process JSON strings returned by API. For example, response_string can be directly accessed after parsing by json.loads(). When using it, you must ensure that the JSON format is correct, otherwise an exception will be thrown.