Esempio String Utility Functions
L'esempio String Utilities include una funzione di flusso con valori di tabella, scritta in Visual C# e Visual Basic, che consente di dividere una stringa delimitata da virgole in una tabella con una colonna, nonché una funzione di aggregazione che consente di convertire una colonna stringa in una stringa delimitata da virgole. Vengono inoltre implementate una funzione scalare e una funzione con valori di tabella che garantiscono funzionalità di ricerca e sostituzione di espressioni regolari.
Per implementare una funzione di flusso con valori di tabella, creare un metodo per la restituzione di un oggetto che implementi l'interfaccia IEnumerable. Il metodo IEnumerable deve essere collegato tramite un attributo a un altro metodo per la compilazione delle righe della funzione con valori di tabella.
Prerequisiti
Per creare ed eseguire questo progetto, è necessario installare il software seguente:
SQL Server o SQL Server Express. È possibile ottenere SQL Server Express gratuitamente dal sito Web documentazione e esempi di SQL Server Express
Database AdventureWorks disponibile nel sito Web di SQL Server Developer
.NET Framework SDK 2.0 o versione successiva oppure Microsoft Visual Studio 2005 o versione successiva. .NET Framework SDK è disponibile gratuitamente.
È necessario inoltre che siano soddisfatte le condizioni seguenti:
L'istanza SQL Server usata deve avere l'integrazione CLR abilitata.
Per abilitare l'integrazione con CLR, effettuare le operazioni seguenti:
Abilitazione dell'integrazione con CLR
- Eseguire i comandi Transact-SQL seguenti:
sp_configure 'clr enabled', 1GORECONFIGUREGONota
Per abilitare l'integrazione con CLR, è necessario disporre dell'autorizzazione
ALTER SETTINGSa livello di server, che viene assegnata implicitamente ai membri dei ruoli predefiniti del serversysadmineserveradmin.Il database AdventureWorks deve essere installato nell'istanza di SQL Server in uso.
Se non si è un amministratore per l'istanza di SQL Server usata, è necessario disporre di un amministratore che concede l'autorizzazione CreateAssembly per completare l'installazione.
Compilazione dell'esempio
Creare ed eseguire l'esempio tramite le istruzioni seguenti:
Aprire un prompt dei comandi di .NET Framework o Visual Studio.
Se necessario, creare una directory per l'esempio. Per questo esempio verrà utilizzata la directory C:\MySample.
In c:\MySample creare
StringUtils.vb(per l'esempio Visual Basic) oStringUtils.cs(per l'esempio C#) e copiare nel file il codice di esempio appropriato, Visual Basic o C#, riportato di seguito.Compilare il codice di esempio dal prompt della riga di comando eseguendo una delle istruzioni seguenti, a seconda del linguaggio scelto.
Vbc /target:library /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\System.Core.dll",C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /debug- /target:library StringUtils.vbCsc/reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.XML.dll /target:library StringUtils.cs
Copiare il codice di installazione Transact-SQL in un file e salvarlo come
Install.sqlnella directory di esempio.Se l'esempio è installato in una directory diversa da
C:\MySample\, modificare il fileInstall.sqlcome indicato, in modo che punti al percorso appropriato.Distribuire l'assembly e la stored procedure eseguendo
sqlcmd -E -I -i install.sqlCopiare lo script di comando di test Transact-SQL in un file e salvarlo come
test.sqlnella directory di esempio.
Eseguire lo script di test con il comando seguente
sqlcmd -E -I -i test.sql
Copiare lo script di pulizia Transact-SQL in un file e salvarlo come
cleanup.sqlnella directory di esempio.Eseguire lo script con il comando seguente
sqlcmd -E -I -i cleanup.sql
Codice di esempio
Di seguito sono illustrati i listati di codice per l'esempio.
C#
using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlTypes;
using System.Data.Sql;
using System.Text.RegularExpressions;
using Microsoft.SqlServer.Server;
/// <summary>
/// This class is provides regular expression operations for Transact-SQL callers
/// </summary>
public sealed class RegularExpression
{
private RegularExpression()
{
}
/// <summary>
/// This method returns a table of matches, groups, and captures based on the input
/// string and pattern string provided.
/// </summary>
/// <param name="sqlInput">What to match against</param>
/// <param name="sqlPattern">What to look for</param>
/// <returns>An object which appears to be reading from SQL Server but which in fact is reading
/// from a memory based representation of the data.</returns>
[SqlFunction(FillRowMethodName = "FillRow")]
public static IEnumerable Matches(SqlString sqlInput, SqlString sqlPattern)
{
string input = (sqlInput.IsNull) ? string.Empty : sqlInput.Value;
string pattern = (sqlPattern.IsNull) ? string.Empty : sqlPattern.Value;
return GetMatches(input, pattern);
}
public static void FillRow(object obj, out int matchId, out int matchIndex, out string matchValue,
out int groupId, out int groupIndex, out string groupValue, out int captureIndex,
out string captureValue)
{
MatchResult result = (MatchResult)obj;
matchId = result.MatchID;
matchIndex = result.MatchIndex;
matchValue = result.MatchValue;
groupId = result.GroupID;
groupIndex = result.GroupIndex;
groupValue = result.GroupValue;
captureIndex = result.CaptureIndex;
captureValue = result.CaptureValue;
}
/// <summary>
/// Generates a list of Match/Group/Capture tuples represented using the
/// MatchResult struct based on the regular expression match of the input
/// string and pattern string provided.
/// </summary>
/// <param name="input">What to match</param>
/// <param name="pattern">What to look for</param>
/// <returns>A list of Match/Group/Capture tuples</returns>
private static List<MatchResult> GetMatches(string input, string pattern)
{
List<MatchResult> result = new List<MatchResult>();
int matchId = 0;
int groupId = 0;
foreach (Match m in Regex.Matches(input, pattern))
{
if (m.Groups.Count < 1)
result.Add(new MatchResult(matchId, m.Index, m.Value, -1, -1, string.Empty, -1, string.Empty));
else
{
groupId = 0;
foreach (Group g in m.Groups)
{
if (g.Captures.Count < 1)
result.Add(new MatchResult(matchId, m.Index, m.Value,
groupId, g.Index, g.Value, -1, string.Empty));
else
{
foreach (Capture c in m.Groups)
{
result.Add(new MatchResult(matchId, m.Index, m.Value,
groupId, g.Index, g.Value, c.Index, c.Value));
}
}
groupId += 1;
}
}
matchId += 1;
}
return result;
}
/// <summary>
/// This method performs a pattern based substitution based on the provided input string, pattern
/// string, and replacement string.
/// </summary>
/// <param name="sqlInput">The source material</param>
/// <param name="sqlPattern">How to parse the source material</param>
/// <param name="sqlReplacement">What the output should look like</param>
/// <returns></returns>
public static string Replace(SqlString sqlInput, SqlString sqlPattern, SqlString sqlReplacement)
{
string input = (sqlInput.IsNull) ? string.Empty : sqlInput.Value;
string pattern = (sqlPattern.IsNull) ? string.Empty : sqlPattern.Value;
string replacement = (sqlReplacement.IsNull) ? string.Empty : sqlReplacement.Value;
return Regex.Replace(input, pattern, replacement);
}
}
/// <summary>
/// This struct is used trepresents a Match/Group/Capture tuple. Instances of this struct are
/// created by the GetMatches method.
/// </summary>
internal struct MatchResult
{
/// <summary>
/// Which match this is
/// </summary>
private int _matchID;
public int MatchID
{
get
{
return this._matchID;
}
}
/// <summary>
/// Where the match starts in the input string
/// </summary>
private int _matchIndex;
public int MatchIndex
{
get
{
return this._matchIndex;
}
}
/// <summary>
/// What string matched the pattern
/// </summary>
private string _matchValue;
public string MatchValue
{
get
{
return this._matchValue;
}
}
/// <summary>
/// Which matching group this is
/// </summary>
private int _groupID;
public int GroupID
{
get
{
return this._groupID;
}
}
/// <summary>
/// Where this group starts in the input string
/// </summary>
private int _groupIndex;
public int GroupIndex
{
get
{
return this._groupIndex;
}
}
/// <summary>
/// What the group matched in the input string
/// </summary>
private string _groupValue;
public string GroupValue
{
get
{
return this._groupValue;
}
}
/// <summary>
/// Where this capture starts in the input string
/// </summary>
private int _captureIndex;
public int CaptureIndex
{
get
{
return this._captureIndex;
}
}
/// <summary>
/// What the capture matched in the input string
/// </summary>
private string _captureValue;
public string CaptureValue
{
get
{
return this._captureValue;
}
}
/// <summary>
/// A convenient constructor which fills in all the fields contained in this struct.
/// </summary>
/// <param name="matchID">Which match this is</param>
/// <param name="matchIndex">Where the match starts in the input string</param>
/// <param name="matchValue">What string matched the pattern</param>
/// <param name="groupID">Which matching group this is</param>
/// <param name="groupIndex">Where this group starts in the input string</param>
/// <param name="groupValue">What the group matched in the input string</param>
/// <param name="captureIndex">Where this capture starts in the input string</param>
/// <param name="captureValue">What the capture matched in the input string</param>
public MatchResult(int matchId, int matchIndex, string matchValue,
int groupId, int groupIndex, string groupValue,
int captureIndex, string captureValue)
{
this._matchID = matchId;
this._matchIndex = matchIndex;
this._matchValue = matchValue;
this._groupID = groupId;
this._groupIndex = groupIndex;
this._groupValue = groupValue;
this._captureIndex = captureIndex;
this._captureValue = captureValue;
}
}
public sealed class StringSplitter
{
/// <summary>
/// The streaming table-valued function used to split the string into a relation
/// </summary>
/// <param name="argument"></param>
/// <returns></returns>
[SqlFunction(FillRowMethodName = "FillRow")]
public static IEnumerable Split(SqlString argument)
{
string value;
if (argument.IsNull)
value = "";
else
value = argument.Value;
return value.Split(',');
}
public static void FillRow(Object obj, out string stringElement)
{
stringElement = (string)obj;
}
/// <summary>
/// Don't allow callers to create instances of this class
/// </summary>
private StringSplitter() { }
}
[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedAggregate(
Microsoft.SqlServer.Server.Format.UserDefined, //use clr serialization to serialize the intermediate result
IsInvariantToNulls = true,//optimizer property
IsInvariantToDuplicates = false,//optimizer property
IsInvariantToOrder = false,//optimizer property
MaxByteSize = 8000)//maximum size in bytes of persisted value
]
public class Concatenate : Microsoft.SqlServer.Server.IBinarySerialize
{
/// <summary>
/// The variable that holds the intermediate result of the concatenation
/// </summary>
private StringBuilder intermediateResult;
/// <summary>
/// Initialize the internal data structures
/// </summary>
public void Init()
{
intermediateResult = new StringBuilder();
}
/// <summary>
/// Accumulate the next value, nop if the value is null
/// </summary>
/// <param name="value"></param>
public void Accumulate(SqlString value)
{
if (value.IsNull)
{
return;
}
intermediateResult.Append(value.Value).Append(',');
}
/// <summary>
/// Merge the partially computed aggregate with this aggregate.
/// </summary>
/// <param name="other"></param>
public void Merge(Concatenate other)
{
intermediateResult.Append(other.intermediateResult);
}
/// <summary>
/// Called at the end of aggregation, to return the results of the aggregation
/// </summary>
/// <returns></returns>
public SqlString Terminate()
{
string output = string.Empty;
//delete the trailing comma, if any
if (intermediateResult != null && intermediateResult.Length > 0)
output = intermediateResult.ToString(0, intermediateResult.Length - 1);
return new SqlString(output);
}
public void Read(BinaryReader r)
{
if (r == null) throw new ArgumentNullException("r");
intermediateResult = new StringBuilder(r.ReadString());
}
public void Write(BinaryWriter w)
{
if (w == null) throw new ArgumentNullException("w");
w.Write(intermediateResult.ToString());
}
}
VB.NET
Imports Microsoft.VisualBasic
Imports Microsoft.SqlServer.Server
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.Data
Imports System.Data.SqlTypes
Imports System.Diagnostics
Imports System.IO
Imports System.Linq
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Text.RegularExpressions
<Serializable(), Microsoft.SqlServer.Server.SqlUserDefinedAggregate(Microsoft.SqlServer.Server.Format.UserDefined, IsInvariantToNulls:=True, IsInvariantToDuplicates:=False, IsInvariantToOrder:=False, MaxByteSize:=8000)> _
Public Class Concatenate
'use clr serialization to serialize the intermediate result
'optimizer property
'optimizer property
'optimizer property
'maximum size in bytes of persisted value
Implements Microsoft.SqlServer.Server.IBinarySerialize
''' <summary>
''' The variable that holds the intermediate result of the concatenation
''' </summary>
Private intermediateResult As StringBuilder
''' <summary>
''' Initialize the internal data structures
''' </summary>
Public Sub Init()
intermediateResult = New StringBuilder()
End Sub
''' <summary>
''' Accumulate the next value, nop if the value is null
''' </summary>
''' <param name="value"></param>
Public Sub Accumulate(ByVal value As SqlString)
If value.IsNull Then
Return
End If
intermediateResult.Append(value.Value).Append(","c)
End Sub
''' <summary>
''' Merge the partially computed aggregate with this aggregate.
''' </summary>
''' <param name="other"></param>
Public Sub Merge(ByVal other As Concatenate)
intermediateResult.Append(other.intermediateResult)
End Sub
''' <summary>
''' Called at the end of aggregation, to return the results of the aggregation
''' </summary>
''' <returns></returns>
Public Function Terminate() As SqlString
Dim output As String = String.Empty
'delete the trailing comma, if any
If Not (intermediateResult Is Nothing) AndAlso intermediateResult.Length > 0 Then
output = intermediateResult.ToString(0, intermediateResult.Length - 1)
End If
Return New SqlString(output)
End Function
Public Sub Read(ByVal r As BinaryReader) Implements Microsoft.SqlServer.Server.IBinarySerialize.Read
If r Is Nothing Then
Throw New ArgumentNullException("r")
End If
intermediateResult = New StringBuilder(r.ReadString())
End Sub
Public Sub Write(ByVal w As BinaryWriter) Implements Microsoft.SqlServer.Server.IBinarySerialize.Write
If w Is Nothing Then
Throw New ArgumentNullException("w")
End If
w.Write(intermediateResult.ToString())
End Sub
End Class
Public NotInheritable Class RegularExpression
Private Sub New()
End Sub
''' <summary>
''' This method returns a table of matches, groups, and captures based on the input
''' string and pattern string provided.
''' </summary>
''' <param name="sqlInput">What to match against</param>
''' <param name="sqlPattern">What to look for</param>
''' <returns>An object which appears to be reading from SQL Server but which in fact is reading
''' from a memory based representation of the data.</returns>
<SqlFunction(Name:="RegexMatches", FillRowMethodName:="FillMatchRow", _
TableDefinition:="MatchID int, MatchIndex int, MatchValue nvarchar(4000), GroupID int, GroupIndex int, GroupValue nvarchar(4000), CaptureIndex int, CaptureValue nvarchar(4000)")> _
Public Shared Function Matches(ByVal sqlInput As SqlString, ByVal sqlPattern As SqlString) As IEnumerable
Dim input As String = String.Empty
If Not sqlInput.IsNull Then
input = sqlInput.Value
End If
Dim pattern As String = String.Empty
If Not sqlPattern.IsNull Then
pattern = sqlPattern.Value
End If
Return GetMatches(input, pattern)
End Function
''' <summary>
''' Invoked by SQL Server when returning a row of the TVF. Splits the MatchResult object into
''' the separate pieces of data which will form the columns of the row.
''' </summary>
''' <param name="row"></param>
''' <param name="matchID"></param>
''' <param name="matchIndex"></param>
''' <param name="matchValue"></param>
''' <param name="groupID"></param>
''' <param name="groupIndex"></param>
''' <param name="groupValue"></param>
''' <param name="captureIndex"></param>
''' <param name="captureValue"></param>
Private Shared Sub FillMatchRow(ByVal row As Object, <Out()> ByRef matchId As Integer, _
<Out()> ByRef matchIndex As Integer, <Out()> ByRef matchValue As String, <Out()> ByRef groupId As Integer, _
<Out()> ByRef groupIndex As Integer, <Out()> ByRef groupValue As String, <Out()> ByRef captureIndex As Integer, _
<Out()> ByRef captureValue As String)
Dim result As MatchResult
result = CType(row, MatchResult)
matchId = result.MatchID
matchIndex = result.MatchIndex
matchValue = result.MatchValue
groupId = result.GroupID
groupIndex = result.GroupIndex
groupValue = result.GroupValue
captureIndex = result.CaptureIndex
captureValue = result.CaptureValue
End Sub
''' <summary>
''' Generates a list of Match/Group/Capture tuples represented using the
''' MatchResult struct based on the regular expression match of the input
''' string and pattern string provided.
''' </summary>
''' <param name="input">What to match</param>
''' <param name="pattern">What to look for</param>
''' <returns>A list of Match/Group/Capture tuples</returns>
Private Shared Function GetMatches(ByVal input As String, ByVal pattern As String) As List(Of MatchResult)
Dim result As List(Of MatchResult) = New List(Of MatchResult)()
Dim matchID As Integer = 0
Dim groupID As Integer = 0
For Each m As Match In Regex.Matches(input, pattern)
If m.Groups.Count < 1 Then
result.Add(New MatchResult(matchID, m.Index, m.Value, -1, -1, _
String.Empty, -1, String.Empty))
Else
groupID = 0
For Each g As Group In m.Groups
If g.Captures.Count < 1 Then
result.Add(New MatchResult(matchID, m.Index, m.Value, _
groupID, g.Index, g.Value, -1, String.Empty))
Else
For Each c As Capture In m.Groups
result.Add(New MatchResult(matchID, m.Index, _
m.Value, groupID, g.Index, g.Value, c.Index, _
c.Value))
Next
End If
groupID += 1
Next
End If
matchID += 1
Next
Return result
End Function
''' <summary>
''' This method performs a pattern based substitution based on the provided input string, pattern
''' string, and replacement string.
''' </summary>
''' <param name="sqlInput">The source material</param>
''' <param name="sqlPattern">How to parse the source material</param>
''' <param name="sqlReplacement">What the output should look like</param>
''' <returns></returns>
<SqlFunction(Name:="RegexReplace", DataAccess:=DataAccessKind.None)> _
Public Shared Function Replace(ByVal sqlInput As SqlString, ByVal sqlPattern As SqlString, ByVal sqlReplacement As SqlString) As String
Dim input As String = String.Empty
If Not sqlInput.IsNull Then
input = sqlInput.Value
End If
Dim pattern As String = String.Empty
If Not sqlPattern.IsNull Then
pattern = sqlPattern.Value.ToString()
End If
Dim replacement As String = String.Empty
If Not sqlReplacement.IsNull Then
replacement = sqlReplacement.Value.ToString()
End If
Return Regex.Replace(input, pattern, replacement)
End Function
End Class
''' <summary>
''' This struct is used to represent a Match/Group/Capture tuple. Instances of
''' this struct are created by the GetMatches method.
''' </summary>
Friend Structure MatchResult
''' <summary>
''' Which match this is
''' </summary>
Private _matchID As Integer
Friend ReadOnly Property MatchID() As Integer
Get
Return Me._matchID
End Get
End Property
''' <summary>
''' Where the match starts in the input string
''' </summary>
Private _matchIndex As Integer
Friend ReadOnly Property MatchIndex() As Integer
Get
Return Me._matchIndex
End Get
End Property
''' <summary>
''' What string matched the pattern
''' </summary>
Private _matchValue As String
Friend ReadOnly Property MatchValue() As String
Get
Return Me._matchValue
End Get
End Property
''' <summary>
''' Which matching group this is
''' </summary>
Private _groupID As Integer
Friend ReadOnly Property GroupID() As Integer
Get
Return Me._groupID
End Get
End Property
''' <summary>
''' Where this group starts in the input string
''' </summary>
Private _groupIndex As Integer
Friend ReadOnly Property GroupIndex() As Integer
Get
Return Me._groupIndex
End Get
End Property
''' <summary>
''' What the group matched in the input string
''' </summary>
Private _groupValue As String
Friend ReadOnly Property GroupValue() As String
Get
Return Me._groupValue
End Get
End Property
''' <summary>
''' Where this capture starts in the input string
''' </summary>
Private _captureIndex As Integer
Friend ReadOnly Property CaptureIndex() As Integer
Get
Return Me._captureIndex
End Get
End Property
''' <summary>
''' What the capture matched in the input string
''' </summary>
Private _captureValue As String
Friend ReadOnly Property CaptureValue() As String
Get
Return Me._captureValue
End Get
End Property
''' <summary>
''' A convenient constructor which fills in all the fields contained in this struct.
''' </summary>
''' <param name="matchID">Which match this is</param>
''' <param name="matchIndex">Where the match starts in the input string</param>
''' <param name="matchValue">What string matched the pattern</param>
''' <param name="groupID">Which matching group this is</param>
''' <param name="groupIndex">Where this group starts in the input string</param>
''' <param name="groupValue">What the group matched in the input string</param>
''' <param name="captureIndex">Where this capture starts in the input string</param>
''' <param name="captureValue">What the capture matched in the input string</param>
Friend Sub New(ByVal matchID As Integer, ByVal matchIndex As Integer, ByVal matchValue As String, ByVal groupID As Integer, ByVal groupIndex As Integer, ByVal groupValue As String, ByVal captureIndex As Integer, ByVal captureValue As String)
Me._matchID = matchID
Me._matchIndex = matchIndex
Me._matchValue = matchValue
Me._groupID = groupID
Me._groupIndex = groupIndex
Me._groupValue = groupValue
Me._captureIndex = captureIndex
Me._captureValue = captureValue
End Sub
End Structure
Public NotInheritable Class StringSplitter
''' <summary>
''' The streaming table-valued function used to split the string into a relation
''' </summary>
''' <param name="argument"></param>
''' <returns></returns>
<SqlFunction(Name:="Split", DataAccess:=DataAccessKind.None, FillRowMethodName:="FillSplitRow", _
TableDefinition:="StringElement nvarchar(128) COLLATE Latin1_General_CI_AS")> _
Public Shared Function Split(ByVal argument As SqlString) As IEnumerable
Dim value As String
If argument.IsNull Then
value = String.Empty
Else
value = argument.Value
End If
Return value.Split(","c)
End Function
Private Shared Sub FillSplitRow(ByVal row As Object, ByRef stringElement As String)
stringElement = CType(row, String)
End Sub
''' <summary>
''' Don't allow callers to create instances of this class
''' </summary>
Private Sub New()
End Sub
End Class
Si tratta dello script di installazione Transact-SQL (Install.sql), che distribuisce l'assembly e crea la stored procedure nel database.
USE AdventureWorks
GO
IF OBJECT_ID(N'RegexMatches', N'FT') is not null
DROP Function RegexMatches;
GO
IF OBJECT_ID(N'Split', N'FT') is not null
DROP Function Split;
GO
IF OBJECT_ID(N'RegexReplace', N'FS') is not null
DROP Function RegexReplace;
GO
IF OBJECT_ID(N'Concatenate', N'AF') is not null
DROP Aggregate Concatenate;
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'StringUtils')
DROP ASSEMBLY StringUtils;
GO
DECLARE @SamplePath nvarchar(1024)
-- You will need to modify the value of the this variable if you have installed the sample someplace other than the default location.
Set @SamplePath = 'C:\MySample\'
CREATE ASSEMBLY [StringUtils]
FROM @SamplePath + 'StringUtils.dll'
WITH permission_set = Safe;
GO
CREATE AGGREGATE [dbo].[Concatenate](@input nvarchar(4000))
RETURNS nvarchar(4000)
EXTERNAL NAME [StringUtils].[Concatenate];
GO
CREATE FUNCTION [dbo].[Split](@input nvarchar(4000))
RETURNS TABLE(StringElement nvarchar(128) COLLATE Latin1_General_CI_AS)
AS EXTERNAL NAME [StringUtils].[StringSplitter].[Split];
GO
CREATE FUNCTION [RegexMatches] (@input nvarchar(max), @pattern nvarchar(max))
RETURNS TABLE(
MatchID int,
MatchIndex int,
MatchValue nvarchar(4000),
GroupID int,
GroupIndex int,
GroupValue nvarchar(4000),
CaptureIndex int,
CaptureValue nvarchar(4000))
AS EXTERNAL NAME [StringUtils].[RegularExpression].[Matches];
GO
CREATE FUNCTION [RegexReplace] (@input nvarchar(max), @pattern nvarchar(max), @replacement nvarchar(max))
RETURNS nvarchar(max)
AS EXTERNAL NAME [StringUtils].[RegularExpression].[Replace]
GO
Di seguito è illustrato lo script test.sqlche consente di testare l'esempio eseguendo le funzioni.
USE AdventureWorks
GO
-- Invoke the tvf
SELECT * FROM dbo.Split('will,this,work');
GO
-- Invoke the aggregate over the results of the tvf
SELECT dbo.Concatenate(StringElement) FROM dbo.Split('will,this,also,work');
GO
-- Find two word pairs where the first word contains an 'r'
SELECT MatchID, MatchIndex, MatchValue,
GroupID, GroupIndex, GroupValue,
CaptureIndex, CaptureValue
FROM dbo.RegexMatches('The quick red fox jumped over the lazy brown dog', '(\w*r\w*)\s(\w+)');
GO
-- A variant of the above with no backtracking
SELECT MatchID, MatchIndex, MatchValue,
GroupID, GroupIndex, GroupValue,
CaptureIndex, CaptureValue
FROM dbo.RegexMatches('The quick red fox jumped over the lazy brown dog', '(?>\w*r\w*)\s(?>\w+)');
GO
-- Swap the subject of the sentence with the object of the sentence.
SELECT dbo.RegexReplace('The quick red fox jumped over the lazy brown dog',
'^The (?<fox>(?:[\w]+\s){3})jumped over the (?<dog>(?:[\w]+\s){2}(?:[\w]+))$',
'The ${dog} jumped over the ${fox}');
Di seguito Transact-SQL viene rimosso l'assembly e le funzioni dal database.
USE AdventureWorks
GO
IF OBJECT_ID(N'RegexMatches', N'FT') is not null
DROP Function RegexMatches;
GO
IF OBJECT_ID(N'Split', N'FT') is not null
DROP Function Split;
GO
IF OBJECT_ID(N'RegexReplace', N'FS') is not null
DROP Function RegexReplace;
GO
IF OBJECT_ID(N'Concatenate', N'AF') is not null
DROP Aggregate Concatenate;
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'StringUtils')
DROP ASSEMBLY StringUtils;
GO
Vedere anche
Scenari di utilizzo ed esempi per l'integrazione con CLR (Common Language Runtime)