Class IsNullQueryFunction

Function for replacing the null value with the placeholder expression.

Inheritance
System.Object
QueryFunction
IsNullQueryFunction
Inherited Members
System.Object.ToString()
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: Terrasoft.Core.DB
Assembly: Terrasoft.Core.dll
Syntax
public class IsNullQueryFunction : QueryFunction, IQueryColumnExpressionConvertible, IQueryColumnExpressionsCollector, ICloneable

Constructors

IsNullQueryFunction()

Initializes a new IsNullQueryFunction instance.

Declaration
public IsNullQueryFunction()

IsNullQueryFunction(IQueryColumnExpressionConvertible, IQueryColumnExpressionConvertible)

Initializes a new IsNullQueryFunction instance for the specified validated expression and substitute expression.

Declaration
public IsNullQueryFunction(IQueryColumnExpressionConvertible checkExpression, IQueryColumnExpressionConvertible replacementExpression)
Parameters
Type Name Description
IQueryColumnExpressionConvertible checkExpression

Expression to check for being equal to null.
IQueryColumnExpressionConvertible replacementExpression

Expression returned by the function if checkExpression is equal to null.
Exceptions
Type Condition
System.ArgumentNullException

If the null value is passed as either the checkExpression or the replacementExpression parameter.

IsNullQueryFunction(IsNullQueryFunction)

Initializes a new IsNullQueryFunction instance that is a clone of the passed-in expression function.

Declaration
public IsNullQueryFunction(IsNullQueryFunction source)
Parameters
Type Name Description
IsNullQueryFunction source

The IsNullQueryFunction function whose clone is being created.

IsNullQueryFunction(QueryColumnExpression, QueryColumnExpression)

Initializes a new IsNullQueryFunction instance for the specified validated expression and substitute expression.

Declaration
public IsNullQueryFunction(QueryColumnExpression checkExpression, QueryColumnExpression replacementExpression)
Parameters
Type Name Description
QueryColumnExpression checkExpression

Expression to check for being equal to null.
QueryColumnExpression replacementExpression

Expression returned by the function if checkExpression is equal to null.

Properties

CheckExpression

Expression of the function argument to check for being equal to the null value.

Declaration
public QueryColumnExpression CheckExpression { get; set; }
Property Value
Type Description
QueryColumnExpression

ReplacementExpression

Expression of the function argument that is returned if the check expression is equal to null.

Declaration
public QueryColumnExpression ReplacementExpression { get; set; }
Property Value
Type Description
QueryColumnExpression

Methods

AddQueryColumnExpressions(QueryColumnExpressionCollection)

Declaration
protected override void AddQueryColumnExpressions(QueryColumnExpressionCollection collection)
Parameters
Type Name Description
QueryColumnExpressionCollection collection
Overrides

AddUsingParameters(QueryParameterCollection)

Adds the passed-in collection of parameters in the function arguments.

Declaration
public override void AddUsingParameters(QueryParameterCollection resultParameters)
Parameters
Type Name Description
QueryParameterCollection resultParameters

Collection of query parameters that are added in the function arguments.
Overrides

BuildSqlText(StringBuilder, DBEngine)

Generates the query text, using the specified System.Text.StringBuilder instance and the DBEngine query builder.

Declaration
public override void BuildSqlText(StringBuilder sb, DBEngine dbEngine)
Parameters
Type Name Description
System.Text.StringBuilder sb

The System.Text.StringBuilder instance used to create query text.
DBEngine dbEngine

The instance of the builder of the database queries.
Overrides

Clone()

Creates the clone of the current IsNullQueryFunction instance.

Declaration
public override object Clone()
Returns
Type Description
System.Object

A new IsNullQueryFunction instance that is a clone of the current instance.
Overrides

Implements

System.ICloneable

Extension Methods