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CLR Method to Canonical Function Mapping

Certain CLR methods are converted to command tree canonical functions, which can be executed on the database. If a CLR method cannot be mapped to a command tree canonical function, an exception will be thrown when translation occurs.

System.String Method (Static) Mapping

System.String method (static) Canonical function

System.String Concat(String str0, String str1)

Concat(str0, str1)

System.String Concat(String str0, String str1, String str2)

Concat(Concat(str0, str1), str2)

System.String Concat(String str0, String str1, String str2, String str03)

Concat(Concat(Concat(str0, str1), str2), str3)

Boolean Equals(String a, String b)

= operator

Boolean IsNullOrEmpty(String value)

(IsNull(value)) OR Length(value) = 0

Boolean op_Equality(String a, String b)

= operator

Boolean op_Inequality(String a , String b)

!= operator

Microsoft.VisualBasic.Strings.Trim(String str)

Trim(str)

Microsoft.VisualBasic.Strings.LTrim(String str)

Ltrim(str)

Microsoft.VisualBasic.Strings.RTrim(String str)

Rtrim(str)

Microsoft.VisualBasic.Strings.Len(String expression)

Length(expression)

Microsoft.VisualBasic.Strings.Left(String str, Int32 Length)

Left(str, Length)

Microsoft.VisualBasic.Strings.Mid(String str, Int32 Start, Int32 Length)

Substring(str, Start, Length)

Microsoft.VisualBasic.Strings.Right(String str, Int32 Length)

Right(str, Length)

Microsoft.VisualBasic.Strings.UCase(String Value)

ToUpper(Value)

Microsoft.VisualBasic.Strings.LCase(String Value)

ToLower(Value)

System.String Method (Instance) Mapping

System.String method (instance) Canonical function Notes

Boolean Contains(String value)

IndexOf(this, value) > 0

Boolean EndsWith(String value)

Right(this, length(value)) = value

Boolean StartsWith(String value)

IndexOf(this, value) = 1

Int32 get_Length()

Length(this)

Int32 IndexOf(String value)

IndexOf(this, value) - 1

System.String Insert(Int32 startIndex, String value)

Concat(Concat(Substring(this, 1, startIndex), value), Substring(this, startIndex+1, Length(this) - startIndex))

System.String Remove(Int32 startIndex)

Substring(this, 1, startIndex)

System.String Remove(Int32 startIndex, Int32 count)

Concat(Substring(this, 1, startIndex) , Substring(this, startIndex + count +1, Length(this) - (startIndex + count)))

Remove(startIndex, count) is only supported if count is an integer greater than or equal to 0.

System.String Replace(String oldValue, String newValue)

Replace(this, oldValue, newValue)

System.String Substring(Int32 startIndex)

Substring(this, startIndex +1, Length(this) - startIndex)

System.String Substring(Int32 startIndex, Int32 length)

Substring(this, startIndex +1, length)

System.String ToLower()

ToLower(this)

System.String ToUpper()

ToUpper(this)

System.String Trim()

Trim(this)

System.String TrimEnd(Char[] trimChars)

RTrim(this)

System.String TrimStart(Char[]trimChars)

LTrim(this)

Boolean Equals(String value)

= operator

System.DateTime Method (Static) Mapping

System.DateTime method (static) Canonical function Notes

Boolean Equals(DateTime t1, DateTime t2)

= operator

System.DateTime get_Now()

CurrentDateTime()

System.DateTime get_UtcNow()

CurrentUtcDateTime()

Boolean op_Equality(DateTime d1, DateTime d2)

= operator

Boolean op_GreaterThan(DateTime t1, DateTime t2)

> operator

Boolean op_GreaterThanOrEqual(DateTime t1, DateTime t2)

>= operator

Boolean op_Inequality(DateTime t1, DateTime t2)

!= operator

Boolean op_LessThan(DateTime t1, DateTime t2)

< operator

Boolean op_LessThanOrEqual(DateTime t1, DateTime t2)

<= operator

Microsoft.VisualBasic.DateAndTime.DatePart( _

ByVal Interval As DateInterval, _

ByVal DateValue As DateTime, _

Optional ByVal FirstDayOfWeekValue As FirstDayOfWeek = VbSunday, _

Optional ByVal FirstWeekOfYearValue As FirstWeekOfYear = VbFirstJan1 _

) As Integer

See the DatePart Function section for more information.

Microsoft.VisualBasic.DateAndTime.Now

CurrentDateTime()

Microsoft.VisualBasic.DateAndTime.Year(DateTime TimeValue)

Year()

Microsoft.VisualBasic.DateAndTime.Month(DateTime TimeValue)

Month()

Microsoft.VisualBasic.DateAndTime.Day(DateTime TimeValue)

Day()

Microsoft.VisualBasic.DateAndTime.Hour(DateTime TimeValue)

Hour()

Microsoft.VisualBasic.DateAndTime.Minute(DateTime TimeValue)

Minute()

Microsoft.VisualBasic.DateAndTime.Second(DateTime TimeValue)

Second()

System.DateTime Method (Instance) Mapping

System.DateTime method (instance) Canonical function

Boolean Equals(DateTime value)

= operator

Int32 get_Day()

Day(this)

Int32 get_Hour()

Hour(this)

Int32 get_Millisecond()

Millisecond(this)

Int32 get_Minute()

Minute(this)

Int32 get_Month()

Month(this)

Int32 get_Second()

Second(this)

Int32 get_Year()

Year(this)

System.DateTimeOffset Method (Instance) Mapping

System.DateTimeOffset method (instance) Canonical function Notes

Int32 get_Day()

Day(this)

Not supported against SQL Server 2005.

Int32 get_Hour()

Hour(this)

Not supported against SQL Server 2005.

Int32 get_Millisecond()

Millisecond(this)

Not supported against SQL Server 2005.

Int32 get_Minute()

Minute(this)

Not supported against SQL Server 2005.

Int32 get_Month()

Month(this)

Not supported against SQL Server 2005.

Int32 get_Second()

Second(this)

Not supported against SQL Server 2005.

Int32 get_Year()

Year(this)

Not supported against SQL Server 2005.

System.DateTimeOffset Method (Static) Mapping

System.DateTimeOffset method (static) Canonical function Notes

System.DateTimeOffset get_Now()

CurrentDateTimeOffset()

Not supported against SQL Server 2005.

System.TimeSpan Method (Instance) Mapping

System.TimeSpan method (instance) Canonical function Notes

Int32 get_Hours()

Hour(this)

Not supported against SQL Server 2005.

Int32 get_Milliseconds()

Millisecond(this)

Not supported against SQL Server 2005.

Int32 get_Minutes()

Minute(this)

Not supported against SQL Server 2005.

Int32 get_Seconds()

Second(this)

Not supported against SQL Server 2005.

DatePart Function

The DatePart Function is mapped to one of several different canonical functions, depending on the value of Interval. The following table displays the canonical function mapping for the supported values of Interval:

Interval value Canonical function

DateInterval.Year

Year()

DateInterval.Month

Month()

DateInterval.Day

Day()

DateInterval.Hour

Hour()

DateInterval.Minute

Minute()

DateInterval.Second

Second()

Mathematical Function Mapping

CLR method Canonical function

System.Decimal.Ceiling(Decimal d)

Ceiling(d)

System.Decimal.Floor(Decimal d)

Floor(d)

System.Decimal.Round(Decimal d)

Round(d)

System.Math.Ceiling(Decimal d)

Ceiling(d)

System.Math.Floor(Decimal d)

Floor(d)

System.Math.Round(Decimal d)

Round(d)

System.Math.Ceiling(Double a)

Ceiling(a)

System.Math.Floor(Double a)

Floor(a)

System.Math.Round(Double a)

Round(a)

Bitwise Operator Mapping

Bitwise operator Canonical function for non-Boolean operands Canonical function for Boolean operands

Bitwise AND operator

BitWiseAnd

op1 AND op2

Bitwise OR operator

BitWiseOr

op1 OR op2

Bitwise NOT operator

BitWiseNot

NOT(op)

Bitwise XOR operator

BitWiseXor

((op1 AND NOT(op2)) OR (NOT(op1) AND op2))

See Also

Other Resources

Reference (LINQ to Entities)