SQL Server BasicsWhat is SQL Server database?What is RDBMS?What is Normalization?Why we use Denormalization?What_is_SQL?What is PL/SQL?Difference between SQL and PL/SQLDatabase TableOne to One RelationshipOne to Many RelationshipMany to Many RelationshipMany to One RelationshipString Data TypesNumber Data TypesDate Data TypesOther Data TypesCreate DatabaseDrop DatabaseCreating and Managing Users in SQL ServerCreate TableAlter TableDrop TableConstraints in SQL serverPrimary KeyForeign KeyUnique KeyCandidate KeyComposite KeyDifference between primary key and candidate keyPrimary key and foreign key relationshipSurrogate KeyCascading Referential Integrity ConstraintsSelf Referential Integrity ConstraintsInsert into statementInsert multiple recordsUpdate statementDelete statementTruncate statementDifference between Delete and TruncateAlias in SQL ServerSelect statementSelect DistinctSelect TopSelect IntoNull Functions(ISNULL(),NULLIF(),COALESCE())Sub QueryIdentity ColumnSequence objectDifference between sequence and identity columnSQL Server ClausesWHERE ClauseOrder By ClauseTop N ClauseGroup By ClauseHaving ClauseDifference between Where and HavingSQL Server OperatorsArithmetic OperatorsComparison OperatorsLogical OperatorsBitwise OperatorsAny OperatorsAll OperatorsUnion OperatorsUnion All OperatorsDifference between Union and Union AllIntersect OperatorExcept OperatorDifference between Except and IntersectJoinsInner JoinLeft JoinRight JoinFull JoinSelf JoinCross JoinViewsWhat are views?Create views using SSMSIndexed ViewsComplex ViewsCheck Option in ViewCheck Encryption in ViewSchema Binding Option in ViewRead-only ViewsUpdatable ViewsAdvantages and disadvantages of viewsCreate multiple views on one tableCan we implement index on views?Can we Perform Insert, update, delete operation on views?Stored Procedure and FunctionsWhat are Stored Procedures?Why we use stored procedures?Passing parameters to Stored procedureUser-Defined FunctionsDifference between UDF and Stored procedurePre-Defined Functions@@Indentity and Scope_IndentityNULLIF, ISNULL and COALESCE
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SQL - One to Many Relationship

A one-to-many relationship in a database refers to a relationship between two entities where one record in one entity can be associated with multiple records in the other entity, but each record in the other entity is associated with only one record in the first entity. It represents a one-way relationship where the "one" side relates to the "many" side.

Let's consider an example of a database for a university that tracks students and their courses. Suppose we have two tables: "Students" and "Courses." Each student can be enrolled in multiple courses, but each course can have only one student associated with it. This represents a one-to-many relationship between the "Students" and "Courses" tables.

Here's a simplified representation of the two tables:

Table: Students
StudentID StudentName Major
1 John Doe Biology
2 Jane Smith History
3 Mark Johnson Chemistry
Table: Courses
CourseID CourseName StudentID
1 Math 101 1
2 English 201 2
3 Physics 301 1
3 History 101 3

In this example, the "StudentID" serves as the primary key in the "Students" table, uniquely identifying each student. The "StudentID" is also a foreign key in the "Courses" table, linking each course to a specific student.

By establishing this one-to-many relationship, we can see that John Doe (StudentID 1) is enrolled in both "Math 101" and "Physics 301," while Jane Smith (StudentID 2) is only enrolled in "English 201." Mark Johnson (StudentID 3) is enrolled in the "History 101" course.

This relationship allows for efficient organization and retrieval of data. For example, we can easily find all the courses a particular student is enrolled in by searching for the corresponding records in the "Courses" table based on the student's "StudentID."

The one-to-many relationship is commonly used in various database scenarios such as customer-orders, parent-child, or teacher-student relationships, where one entity can have multiple related records in another entity.

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