sql interview questions for java developers

. 28th, Programming question: Calculate 2 times 8 in the most efficient way? Programmers with a C background are particularly interested in asking such questions. 2 29th, two object values are the same (x.equals (y) = = true), but can have different hash code, this sentence is correct? No, there's the same hash code. 30th, when an object is passed as a parameter to a method, this method can change the property of the object and return the result

1.mysql Date (days) group BY2.servlet life cycle3. Different ways to define string = = and equals4.js string defines a new method5.public Private protected Default Difference6. Multi-threaded scenarios and solutions7. Talk about your knowledge of database affairs.Understanding and usage of IOC AOP in 8.spring9. About Spring's management of beans10. How to use spring-managed beans in code11.hibernate How to define relationships between tables12.hibernate How to execute custom SQL13. Please descri

) 71. What are the similarities and differences between synchronized and java. util. concurrent. locks. Lock?The main point is that Lock can complete all functions implemented by synchronized. Major difference: Lock has more precise thread semantics and better performance than synchronized. Synchronized Automatically releases the Lock, which must be manually released by the programmer and must be released in the finally clause. 72. EJB roles and thre

I. Application of the factory model in development Interview Questions:Write a simple calculator. Code implementation: Abstract An operation class: Package COM. qianyan. calcuator; public abstract class operation {// number one private double num1; // number two private double num2; Public double getnum1 () {return num1;} public void setnum1 (double num1) {This. num1 = num1;} public double getnum2 () {return num2;} public void setnum2 (double num2)

the value assigned to the variable is immutable, that is, it is a constant. If final modifies an object, it indicatesThe reference assigned to this variable is immutable,What cannot be changed is the reference saved by this variable, and it is not the object pointed to by this reference. In the second case, final has the same meaning as in the first case. ActualFor the first two cases, there is a more appropriate description of the meaning of final, that is, if a variable or method parameter is

The dashed box represents the interface, the solid wireframe represents the entity class, The thick wireframe represents the most commonly used entity classes, the dashed arrows indicate the implementation of the interface, and the implementation arrows indicate that the class can make objects of the class that the arrows refer to. Collection: Allows only one object to be placed in each location. It includes a list of "holding a set of objects in a certain order", and a set that "only allo

difference between the 5.sendRedirect () and Forward () methods?The Sendredirect () method creates a new request, and the forward () method simply forwards the request to a new target. After redirection (redirect), objects that were within the scope of the previous request are invalidated because a new request is generated, and after forwarding (forwarding), objects within the scope range of the previous request can be accessed. Sendredirect () is generally considered to be slower than forward

Recently, you need to manually write SQL statements directly into Java code and write SQL statements, and there are a few minor issues to be aware of.First of all I wrote a few simple SQL statements, self-thought no problem, but the compilation of direct error. 1 String str = "INSERT into XXX (a,b,c) VALUES ('" A.geta

character set toThree. Query statements1. Please use an SQL statement to query the total number of people in each departmentSelect department_name,COUNT(DISTINCT from wcemployGROUP by Department_name2. Use an SQL statement to find out the average salary of the staff in different departments as "fitter"Select department_name,AVG from wcemploywhere type= ' Fitter ' GROUP by department_name//If there is no