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1. What are the Sql Joins? Sql Joins are the way to get data from many tables based on some logical conditions. The different types of Joins in Sql Server are 1) Inner join or Equi join 2) Self Join (it can be considered as the part of Inner join) 3) Outer Join 4) Cross […]
Continue Reading1. What is the difference between the Union and Union All? 1) Union is used to select distinct data from the tables but Union All allows duplicate rows to be selected from the tables. 2) The second difference between Union and Union All can be given on the basic of their uses. Union All can […]
Continue Reading1. What is the Normalization? Normalization:-Normalization can be defined as the process of organization the data to reduce the redundant table data to the minimum. This process is carried out by dividing the database into two or more than two tables and defining relationship between them so that deletion, updation and insertion can be made […]
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Group By:- Group By clauses is used to groups rows based on the distinct values of the specified columns. The syntax of the Group by clause is:- Select column1, column2, column3, aggregate_function(expression ) From TableName Where (condition) Group By Column1, column2, column3 For Example, suppose we have a […]
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Both Having Clause and Where clause is used to filter the data coming from the Select statement, but still there are some differences between them. These difference are given below:- To show the difference between the Where Clause and the Having clause we will going to use the table EmployeeDeptInfo whose create query statement is […]
Continue ReadingSometimes duplicate values in tables can create a major problem when we do not make a primary key or a unique key on a table. In these cases we need to find out the duplicate records and need to delete them. We can use the Having Clause to find out that duplicate records.we show this […]
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Views:- View can be described as virtual table which derived its data from one or more than one table columns.It is stored in the database. It is used to implements the security mechanism in the Sql Server. For example, suppose there is table called Employeeinfo whose structure is given below:- Create table EmployeeInfo(EmpId int, EmpName […]
Continue ReadingSecond Normal Form (2NF) :-A table is said to be in its Second Normal Form if it satisfied the following conditions:- 1) It satisfies the condition for the First Normal Form (1NF), 2) It do not includes any partial dependencies where a column is dependent only a part of a primary key. For example suppose we have […]
Continue ReadingThird Normal Form (3NF) :- A table is said to be in the Third Normal form (3NF) if it satisfy the following conditions:- 1) It should be in the 2NF 2) It should not contain any transitive dependency which means that any non key column of the table should not be dependent on another non […]
Continue ReadingFirst Normal Form (INF) A table is said to be in a First Normal Form (1NF) if it satisfy the following conditions:- 1)If the columns of the table only contain atomic values (Single, indivisible). 2)Primary key is defined for the table 3)All the columns of the table are defined on the primary key.The first condition […]
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