Introduction
This chapter demonstrates about the LINQ Operators. LINQ Standard Query Operators is defined as the set of extension formed a query. Following are the concepts covered in this chapter.
- Different Types of Operators
Description
LINQ Operators are have the some range of capabilities like sorting, filtering, aggregation, projection etc and operators are categorised into different types some operators are listed below.
- Join Operators
- Filtering Operators
- Grouping Operators
- Sorting Operators
- Aggregation Operators
- Projection Operators
- Set Operations
- Quantifier Operators
- Equality Operators
Description
Join is a keyword which is used to link two or more collections based on some conditions. Here some Join operators are listed below
- Cross Join
- Cross Join with Group Join
- Group Join
- Left Outer Join
- Cross Join Cross join is used perform joining of two collections based on the condition equality. Operator join C# Query Expression Syntax join ... in ... on ... equals ... VB Query Expression Syntax From x In ... y In ... Where x.a = y.a
- Cross Join with Group Join Which is both combination of cross join and group join.
- Group Join Group Join is used to perform bundle of elements at a time. Operator GroupJoin C# Query Expression Syntax join ... in ... on ... equals ... into ... VB Query Expression Syntax Group Join ... In ... on ...
- Left Outer Join Left Outer Join is used to join left hand side elements at least once even though the condition is not satisfied.
Description
Filtering operators are used to restrict the result set and which have some selected statements to satisfy the condition. Some filtering operators are listed below
- Where
- ofType
- Where Where is used to get the data based on some condition. Operator Where C# Query Expression Syntax where VB Query Expression Syntax where
- ofType ofType is used to get the data based on some type. Operator ofType C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
Description
Grouping operators are used to gather some data into the groups which is based some commonly shared attributes. Some grouping operators are listed below.
- groupBy
- ToLookup
- groupBy Which gather the sequemce items into group and returns IEnumarable collections of IGrouping type Operator GroupBy C# Query Expression Syntax group ... by or group ... by ... into ... VB Query Expression Syntax group ... by ... into ..
- ToLookup Which is used execute the grouping operation in the sequence of key pairs are returned. Operator ToLookup C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
Description
Sorting operators are used to arrange the elements in a order based on basis of a attributes. Following are the some sorting operators are listed below.
- OrderBy
- ThenBy
- Reverse
- OrderByDescending
- ThenByDescending
- OrderBy Which is used sort the values in assending order. Operator OrderBy C# Query Expression Syntax orderBy VB Query Expression Syntax OrderBy
- ThenBy Which is used sort the Secondary values in assending order. Operator ThenBy C# Query Expression Syntax orderby... , .... VB Query Expression Syntax Order By ... , ....
- Reverse Which is used to get the reverse order of the elements. Operator Reverse C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
- OrderByDescending Which is used to sort the values in descending order. Operator OrderByDescending C# Query Expression Syntax orderby ...descending VB Query Expression Syntax orderby ...descending
- ThenByDescending Which is used to sort the secondary values in descending order. Operator ThenByDescending C# Query Expression Syntax orderby... , .... descending VB Query Expression Syntax Order By... , .... descending
Description
Aggregation operators are used to crate aggregation LINQ by using desired type of aggregation. Following are the some aggregate operators are shown below.
- Min
- Max
- Count
- Sum
- Aggergate
- Min Used get the minimum value from the collection. Operator Max C# Query Expression Syntax Not Applicable VB Query Expression Syntax Aggregate ... In ... Into Max()
- Max Used get the maximum value from the collection. Operator Min C# Query Expression Syntax Not applicable VB Query Expression Syntax Aggregate ... In ... Into Min()
- Sum Used to get the sum of values from the collection. Operator Sum C# Query Expression Syntax Not applicable VB Query Expression Syntax Aggregate ... In ... Into Sum()
- Count Used to satisfy the predicate function in a collection. Operator Count C# Query Expression Syntax Not applicable VB Query Expression Syntax Aggregate ... In ... Into Count()
- Aggregate Used to perform aggregation operation on a collection of values. Operator Aggeragate C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
Description
Projection is used to transform the object into altogether new form. Following are the some projection operators are listed below.
- Select
- SelectMany
- Select Which operates the project values based on the transform function. Operator Select C# Query Expression Syntax Select VB Query Expression Syntax Select
- SelectMany Which is used to produce the sequence of values based on transform function. Operator SelectMany C# Query Expression Syntax Use Multiple form clauses VB Query Expression Syntax Use Multiple form clauses
Description
Set operations consist of four operations each operate produce a result based on different criteria. Following are the 4 set operations are listed below.
- Except
- Union
- Distinct
- Intersect
- Except Which is used to compare the both the values and return only one value from collection. Operator Except C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
- Union Which is used to get the combination different collection list without any dupilcate content. Operator Union C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
- Distinct Which is used to filter the duplicate values from the collection. Operator Distinct C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
- Intersect Which is used to produce the identical values fro the collections. Operator Intersect C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
Description
Which is used to produce the Boolean values if sequence satisfy the specific condition. Following are the some quantifier operators are listed below.
- Any
- All
- Contain
- Any
Which is used search if any element the satisfy the given condition
Operator
Any
C# Query Expression Syntax
Not applicable
VB Query Expression Syntax
Aggregate ... In ... Into All (...)
- All
Which retuns the True value if all the elements satisfy the given condition.
Operator
All
C# Query Expression Syntax
Not applicable
VB Query Expression Syntax
Aggregate ... In ... Into All (...)
- Contain Which is used to filter the duplicate values from the collection. Operator Distinct C# Query Expression Syntax Not applicable VB Query Expression Syntax Not applicable
Points
- LINQ consist of the several types of operators.
- operators are categorised based on their functionality.
- Each operator produce different results.