UTF8 字符串用户定义数据类型 (UDT)
SQL Server 的 UTF8String 示例说明了用户定义数据类型的实现。 该示例显示了 UTF8 用户定义数据类型的实现,UTF8 用户定义数据类型扩展了数据库的类型系统,允许其存储 UTF8 编码值。 此类型还实现了 Unicode 字符串与 UTF8 字符串之间互相转换的代码。
先决条件
若要创建和运行此项目,必须安装下列软件:
SQL Server 或 SQL Server Express。 您可以从 SQL Server Express Documentation and Samples (Express 文档和示例)网站免费获取 SQL Server Express。
SQL Server 开发人员网站提供的 AdventureWorks 数据库
.NET Framework SDK 2.0 或更高版本,或 Microsoft Visual Studio 2005 或更高版本。 您可以免费获取 .NET Framework SDK。
此外,还必须满足以下条件:
您使用的 SQL Server 实例必须已启用 CLR 集成。
若要启用 CLR 集成,请执行以下步骤:
启用 CLR 集成
- 执行以下 Transact-SQL 命令:
sp_configure 'clr enabled', 1
GO
RECONFIGURE
GO
注意 若要启用 CLR,您必须具有 ALTER SETTINGS 服务器级别权限,sysadmin 和 serveradmin 固定服务器角色的成员隐式拥有该权限。
必须在您使用的 SQL Server 实例上安装 AdventureWorks 数据库。
如果您不是要使用的 SQL Server 实例的管理员,则必须让管理员授予您 CreateAssembly 权限,才能完成安装。
生成示例
按照以下说明创建和运行该示例:
打开 Visual Studio 或 .NET Framework 命令提示符。
如有必要,为您的示例创建目录。 对于此示例,我们将使用 C:\MySample。
在 c:\MySample 中,创建 Utf8String.vb(用于 Visual Basic 示例)或 Utf8String.cs(用于 C# 示例),并将相应的 Visual Basic 或 C# 示例代码(如下所示)复制到该文件中。
从命令行提示符执行以下代码之一(具体取决于所选的语言),对示例代码进行编译。
Vbc /reference: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 /target:library Utf8String.vb
Csc /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 Utf8String.cs
将 Transact-SQL 安装代码复制到一个文件中,并在示例目录中将其另存为 Install.sql。
如果该示例安装在 C:\MySample\ 之外的目录中,请按说明编辑文件 Install.sql 以指向该位置。
通过执行以下命令部署程序集和存储过程:
- sqlcmd -E -I -i install.sql
将 Transact-SQL 测试命令脚本复制到一个文件中,并在示例目录中将其另存为 test.sql。
使用以下命令执行测试脚本:
- sqlcmd -E -I -i test.sql
将 Transact-SQL 清除脚本复制到一个文件中,并在示例目录中将其另存为 cleanup.sql。
使用以下命令执行该脚本:
- sqlcmd -E -I -i cleanup.sql
示例代码
下面是此示例的代码列表。
C#
using System;
using System.Xml;
using System.Data.Sql;
using System.Data.SqlTypes;
using System.Globalization;
using Microsoft.SqlServer.Server;
using System.Runtime.CompilerServices;
using System.Reflection;
[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedType(Microsoft.SqlServer.Server.Format.UserDefined, IsByteOrdered = true, MaxByteSize = 8000)]
public class Utf8String : INullable, IComparable, Microsoft.SqlServer.Server.IBinarySerialize
{
#region conversion to/from Unicode strings
/// <summary>
/// Parse the given string and return a utf8 representation for it.
/// </summary>
/// <param name="sqlString"></param>
/// <returns></returns>
public static Utf8String Parse(SqlString sqlString)
{
if (sqlString.IsNull)
return Utf8String.Null;
return new Utf8String(sqlString.Value);
}
/// <summary>
/// Get/Set the utf8 bytes for this string.
/// </summary>
public SqlBinary Utf8Bytes
{
get
{
if (this.IsNull)
return SqlBinary.Null;
if (this.m_Bytes != null)
return this.m_Bytes;
if (this.m_String != null)
{
this.m_Bytes = System.Text.Encoding.UTF8.GetBytes(this.m_String);
return new SqlBinary(this.m_Bytes);
}
throw new NotSupportedException("cannot return bytes for empty instance");
}
set
{
if (value.IsNull)
{
this.m_Bytes = null;
this.m_String = null;
}
else
{
this.m_Bytes = value.Value;
this.m_String = null;
}
}
}
/// <summary>
/// Return a unicode string for this type.
/// </summary>
[Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true, DataAccess = Microsoft.SqlServer.Server.DataAccessKind.None, SystemDataAccess = Microsoft.SqlServer.Server.SystemDataAccessKind.None)]
public override string ToString()
{
if (this.IsNull)
return null;
if (this.m_String != null)
return this.m_String;
if (this.m_Bytes != null)
{
this.m_String = System.Text.Encoding.UTF8.GetString(this.m_Bytes);
return this.m_String;
}
throw new NotSupportedException("don't know how to return string from empty instance");
}
/// <summary>
/// Return a SqlStr
/// </summary>
public SqlString ToSqlString()
{
if (this.IsNull)
return SqlString.Null;
return new SqlString(this.ToString());
}
private SqlString GetSortKeyUsingCultureInternal(CultureInfo culture, bool ignoreCase,
bool ignoreNonSpace, bool ignoreWidth)
{
if (this.IsNull)
return SqlString.Null;
SqlCompareOptions compareOptions = SqlCompareOptions.None;
if (ignoreCase)
compareOptions = compareOptions | SqlCompareOptions.IgnoreCase;
if (ignoreNonSpace)
compareOptions = compareOptions | SqlCompareOptions.IgnoreNonSpace;
if (ignoreWidth)
compareOptions = compareOptions | SqlCompareOptions.IgnoreWidth;
return new SqlString(this.ToString(), culture.LCID, compareOptions);
}
[Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = true, IsPrecise = true)]
public SqlString GetSortKeyUsingCulture(string cultureName, bool ignoreCase,
bool ignoreNonSpace, bool ignoreWidth)
{
CultureInfo culture = CultureInfo.CreateSpecificCulture(cultureName);
if (culture == null)
throw new ArgumentException(string.Format(
CultureInfo.InvariantCulture,
"Culture {0} not recognized.", cultureName));
return this.GetSortKeyUsingCultureInternal(culture, ignoreCase,
ignoreNonSpace, ignoreWidth);
}
[Microsoft.SqlServer.Server.SqlMethod(IsDeterministic = false)]
public SqlString GetSortKey(bool ignoreCase, bool ignoreNonSpace, bool ignoreWidth)
{
return this.GetSortKeyUsingCultureInternal(CultureInfo.CurrentCulture,
ignoreCase, ignoreNonSpace, ignoreWidth);
}
#endregion
#region comparison operators
public override bool Equals(object obj)
{
return this.CompareTo(obj) == 0;
}
public static bool operator ==(Utf8String utf8String, Utf8String other)
{
if (utf8String.IsNull) throw new ArgumentException(string.Empty);
return utf8String.Equals(other);
}
public static bool operator !=(Utf8String utf8String, Utf8String other)
{
return !(utf8String == other);
}
public static bool operator <(Utf8String utf8String, Utf8String other)
{
if (utf8String == null) throw new ArgumentException(string.Empty);
return (utf8String.CompareTo(other) < 0);
}
public static bool operator >(Utf8String utf8String, Utf8String other)
{
if (utf8String == null) throw new ArgumentException(string.Empty);
return (utf8String.CompareTo(other) > 0);
}
private int CompareUsingCultureInternal(Utf8String other, CultureInfo culture, bool ignoreCase,
bool ignoreNonSpace, bool ignoreWidth)
{
// By definition
if (other == null)
return 1;
if (this.IsNull)
if (other.IsNull)
return 0;
else
return -1;
if (other.IsNull)
return 1;
return this.GetSortKeyUsingCultureInternal(culture, ignoreCase, ignoreNonSpace,
ignoreWidth).CompareTo(other.GetSortKeyUsingCultureInternal(culture, ignoreCase,
ignoreNonSpace, ignoreWidth));
}
public int CompareUsingCulture(Utf8String other, string cultureName, bool ignoreCase,
bool ignoreNonSpace, bool ignoreWidth)
{
CultureInfo culture = CultureInfo.CreateSpecificCulture(cultureName);
if (culture == null)
throw new ArgumentException(string.Format(
CultureInfo.InvariantCulture,
"Culture {0} not recognized.", cultureName));
return this.CompareUsingCultureInternal(other, culture, ignoreCase,
ignoreNonSpace, ignoreWidth);
}
public int Compare(Utf8String other, bool ignoreCase,
bool ignoreNonSpace, bool ignoreWidth)
{
return this.CompareUsingCultureInternal(other, CultureInfo.CurrentCulture, ignoreCase,
ignoreNonSpace, ignoreWidth);
}
public override int GetHashCode()
{
if (this.IsNull)
return 0;
return this.ToString().GetHashCode();
}
public int CompareTo(object obj)
{
if (obj == null)
return 1; //by definition
Utf8String s = obj as Utf8String;
if (s == null)
throw new ArgumentException("the argument to compare is not a Utf8String");
if (this.IsNull)
{
if (s.IsNull)
return 0;
return -1;
}
if (s.IsNull)
return 1;
return this.ToString().CompareTo(s.ToString());
}
#endregion
#region private state and constructors
private string m_String;
private byte[] m_Bytes;
public Utf8String(string value)
{
this.m_String = value;
}
public Utf8String(byte[] bytes)
{
this.m_Bytes = bytes;
}
#endregion
#region UserDefinedType boilerplate code
public bool IsNull
{
get
{
return this.m_String == null && this.m_Bytes == null;
}
}
public static Utf8String Null
{
get
{
Utf8String str = new Utf8String((string)null);
return str;
}
}
public Utf8String()
{
}
#endregion
#region IBinarySerialize Members
public void Write(System.IO.BinaryWriter w)
{
if (w == null) throw new ArgumentException(string.Empty);
byte header = (byte)(this.IsNull ? 1 : 0);
w.Write(header);
if (header == 1)
return;
byte[] bytes = this.Utf8Bytes.Value;
w.Write(bytes.Length);
w.Write(bytes);
}
public void Read(System.IO.BinaryReader r)
{
if (r == null) throw new ArgumentException(string.Empty);
byte header = r.ReadByte();
if ((header & 1) > 0)
{
this.m_Bytes = null;
return;
}
int length = r.ReadInt32();
this.m_Bytes = r.ReadBytes(length);
}
#endregion
}
Visual Basic
Imports Microsoft.SqlServer.Server
Imports Microsoft.VisualBasic
Imports System
Imports System.Collections
Imports System.Data
Imports System.Data.SqlTypes
Imports System.Diagnostics
Imports System.Globalization
<Serializable(), Microsoft.SqlServer.Server.SqlUserDefinedType(Microsoft.SqlServer.Server.Format.UserDefined, IsByteOrdered:=True, MaxByteSize:=8000), CLSCompliant(False)> _
Public Class Utf8String
Implements INullable, IComparable, Microsoft.SqlServer.Server.IBinarySerialize
#Region "Conversion to/from Unicode strings"
''' <summary>
''' Parse the given string and return a utf8 representation for it.
''' </summary>
''' <param name="sqlString"></param>
''' <returns></returns>
Public Shared Function Parse(ByVal sqlString As SqlString) As Utf8String
If sqlString.IsNull Then
Return Utf8String.Null
End If
Return New Utf8String(sqlString.Value)
End Function
''' <summary>
''' Get/Set the utf8 bytes for this string.
''' </summary>
Public Property Utf8Bytes() As SqlBinary
Get
If Me.IsNull Then
Return SqlBinary.Null
End If
If Not (Me.privBytes Is Nothing) Then
Return Me.privBytes
End If
If Not (Me.privString Is Nothing) Then
Me.privBytes = System.Text.Encoding.UTF8.GetBytes(Me.privString)
Return New SqlBinary(Me.privBytes)
End If
Throw New NotSupportedException("Cannot return bytes for empty instance")
End Get
Set(ByVal value As SqlBinary)
If value.IsNull Then
Me.privBytes = Nothing
Me.privString = Nothing
Else
Me.privBytes = value.Value
Me.privString = Nothing
End If
End Set
End Property
''' <summary>
''' Return a unicode string for this type.
''' </summary>
<Microsoft.SqlServer.Server.SqlMethod(IsDeterministic:=True, IsPrecise:=True, DataAccess:=Microsoft.SqlServer.Server.DataAccessKind.None, SystemDataAccess:=Microsoft.SqlServer.Server.SystemDataAccessKind.None)> _
Public Overrides Function ToString() As String
If Me.IsNull Then
Return Nothing
End If
If Not (Me.privString Is Nothing) Then
Return Me.privString
End If
If Not (Me.privBytes Is Nothing) Then
Me.privString = System.Text.Encoding.UTF8.GetString(Me.privBytes)
Return Me.privString
End If
Throw New NotSupportedException("dont know how to return string from empty instance")
End Function
''' <summary>
''' Return a SqlStr
''' </summary>
Public Function ToSqlString() As SqlString
If Me.IsNull Then
Return SqlString.Null
End If
Return New SqlString(Me.ToString())
End Function
Private Function GetSortKeyUsingCultureInternal(ByVal culture As CultureInfo, ByVal ignoreCase As Boolean, _
ByVal ignoreNonSpace As Boolean, ByVal ignoreWidth As Boolean) As SqlString
If Me.IsNull Then
Return SqlString.Null
End If
Dim compareOptions As SqlCompareOptions = SqlCompareOptions.None
If ignoreCase Then
compareOptions = compareOptions Or SqlCompareOptions.IgnoreCase
End If
If ignoreNonSpace Then
compareOptions = compareOptions Or SqlCompareOptions.IgnoreNonSpace
End If
If ignoreWidth Then
compareOptions = compareOptions Or SqlCompareOptions.IgnoreWidth
End If
Return New SqlString(Me.ToString(), culture.LCID, compareOptions)
End Function
<Microsoft.SqlServer.Server.SqlMethod(IsDeterministic:=True, IsPrecise:=True)> _
Public Function GetSortKeyUsingCulture(ByVal cultureName As String, ByVal ignoreCase As Boolean, _
ByVal ignoreNonSpace As Boolean, ByVal ignoreWidth As Boolean) As SqlString
Dim culture As CultureInfo = CultureInfo.CreateSpecificCulture(cultureName)
If culture Is Nothing Then
Throw New ArgumentException(String.Format(CultureInfo.InvariantCulture, _
"Culture {0} not recognized.", cultureName))
End If
Return Me.GetSortKeyUsingCultureInternal(culture, ignoreCase, ignoreNonSpace, ignoreWidth)
End Function
<Microsoft.SqlServer.Server.SqlMethod(IsDeterministic:=True, IsPrecise:=True)> _
Public Function GetSortKey(ByVal ignoreCase As Boolean, ByVal ignoreNonSpace As Boolean, _
ByVal ignoreWidth As Boolean) As SqlString
Return Me.GetSortKeyUsingCultureInternal(CultureInfo.CurrentCulture, ignoreCase, ignoreNonSpace, ignoreWidth)
End Function
#End Region
#Region "Comparison operators"
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Return Me.CompareTo(obj) = 0
End Function
Public Shared Operator =(ByVal utf8StringValue As Utf8String, ByVal other As Utf8String) As Boolean
If utf8StringValue Is Nothing Then
Throw New ArgumentException(String.Empty)
End If
Return utf8StringValue.Equals(other)
End Operator
Public Shared Operator <>(ByVal utf8StringValue As Utf8String, ByVal other As Utf8String) As Boolean
Return Not (utf8StringValue = other)
End Operator
Public Shared Operator <(ByVal utf8StringValue As Utf8String, ByVal other As Utf8String) As Boolean
If utf8StringValue Is Nothing Then
Throw New ArgumentException(String.Empty)
End If
Return (utf8StringValue.CompareTo(other) < 0)
End Operator
Public Shared Operator >(ByVal utf8StringValue As Utf8String, ByVal other As Utf8String) As Boolean
If utf8StringValue Is Nothing Then
Throw New ArgumentException(String.Empty)
End If
Return (utf8StringValue.CompareTo(other) > 0)
End Operator
Private Function CompareUsingCultureInternal(ByVal other As Utf8String, ByVal culture As CultureInfo, _
ByVal ignoreCase As Boolean, ByVal ignoreNonSpace As Boolean, _
ByVal ignoreWidth As Boolean) As Integer
'By definition
If other Is Nothing Then
Return 1
End If
If Me.IsNull Then
If other.IsNull Then
Return 0
Else
Return -1
End If
End If
If other.IsNull Then
Return 1
End If
Return Me.GetSortKeyUsingCultureInternal(culture, ignoreCase, ignoreNonSpace, _
ignoreWidth).CompareTo(other.GetSortKeyUsingCultureInternal(culture, ignoreCase, _
ignoreNonSpace, ignoreWidth))
End Function
Public Function CompareUsingCulture(ByVal other As Utf8String, ByVal cultureName As String, _
ByVal ignoreCase As Boolean, ByVal ignoreNonSpace As Boolean, _
ByVal ignoreWidth As Boolean) As Integer
Dim culture As CultureInfo = CultureInfo.CreateSpecificCulture(cultureName)
If culture Is Nothing Then
Throw New ArgumentException(String.Format(CultureInfo.InvariantCulture, _
"Culture {0} not recognized.", cultureName))
End If
Return Me.CompareUsingCultureInternal(other, culture, ignoreCase, _
ignoreNonSpace, ignoreWidth)
End Function
Public Function Compare(ByVal other As Utf8String, ByVal ignoreCase As Boolean, ByVal ignoreNonSpace As Boolean, _
ByVal ignoreWidth As Boolean) As Integer
Return Me.CompareUsingCultureInternal(other, CultureInfo.CurrentCulture, ignoreCase, _
ignoreNonSpace, ignoreWidth)
End Function
Public Overrides Function GetHashCode() As Integer
If Me.IsNull Then
Return 0
End If
Return Me.ToString().GetHashCode()
End Function
Public Function CompareTo(ByVal obj As Object) As Integer Implements IComparable.CompareTo
If obj Is Nothing Then
Return 1 'by definition
End If
Dim s As Utf8String = CType(obj, Utf8String)
If s Is Nothing Then
Throw New ArgumentException("the argument to compare is not a Utf8String")
End If
If Me.IsNull Then
If s.IsNull Then
Return 0
End If
Return -1
End If
If s.IsNull Then
Return 1
End If
Return Me.ToString().CompareTo(s.ToString())
End Function
#End Region
#Region "Private state and constructors"
Private privString As String
Private privBytes() As Byte
Public Sub New(ByVal value As String)
Me.privString = value
'Me.privBytes = Nothing
End Sub
Public Sub New(ByVal bytes() As Byte)
Me.privBytes = bytes
'Me.privString = Nothing
End Sub
#End Region
#Region "UserDefinedType boilerplate code"
Public ReadOnly Property IsNull() As Boolean Implements INullable.IsNull
Get
Return Me.privString Is Nothing AndAlso Me.privBytes Is Nothing
End Get
End Property
Public Shared ReadOnly Property Null() As Utf8String
Get
Dim str As New Utf8String(CStr(Nothing))
Return str
End Get
End Property
Public Sub New()
End Sub
#End Region
#Region "IBinarySerialize Members"
Public Sub Write(ByVal w As System.IO.BinaryWriter) Implements Microsoft.SqlServer.Server.IBinarySerialize.Write
If w Is Nothing Then
Throw New ArgumentException(String.Empty)
End If
Dim header As Byte
If (Me.IsNull) Then
header = 1
Else
header = 0
End If
w.Write(header)
If header = 1 Then
Return
End If
Dim bytes As Byte() = Me.Utf8Bytes.Value
w.Write(bytes.Length)
w.Write(bytes)
End Sub
Public Sub Read(ByVal r As System.IO.BinaryReader) Implements Microsoft.SqlServer.Server.IBinarySerialize.Read
If r Is Nothing Then
Throw New ArgumentException(String.Empty)
End If
Dim header As Byte = r.ReadByte()
If (header And 1) > 0 Then
Me.privBytes = Nothing
Return
End If
Dim length As Integer = r.ReadInt32()
Me.privBytes = r.ReadBytes(length)
End Sub
#End Region
End Class
这是 Transact-SQL 安装脚本 (Install.sql),该脚本在数据库中部署程序集并创建 UDT。
USE AdventureWorks;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE ([name] = N'ResumeFullName') AND ([type] = 'FN'))
DROP FUNCTION [dbo].[ResumeFullName];
GO
IF EXISTS (SELECT * FROM sys.indexes WHERE NAME = N'IX_utf8test_ustr')
DROP INDEX utf8test.IX_utf8test_ustr;
GO
IF EXISTS (SELECT * FROM sys.tables WHERE name = N'utf8test')
DROP TABLE [dbo].[utf8test];
GO
IF EXISTS (SELECT * FROM sys.tables WHERE name = N'ResumeNames')
DROP TABLE [dbo].[ResumeNames];
GO
IF EXISTS (SELECT * FROM sys.types WHERE name = N'Utf8String')
DROP TYPE [Utf8String];
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'UTF8String')
DROP ASSEMBLY UTF8String;
GO
DECLARE @SamplesPath nvarchar(1024)
-- You may need to modify the value of the this variable if you have installed
-- the sample someplace other than the default location.
set @SamplesPath= N'C:\MySample\'
CREATE ASSEMBLY UTF8String
FROM @SamplesPath +'UTF8String.dll';
GO
CREATE TYPE [Utf8String]
EXTERNAL NAME [UTF8String].[Utf8String];
GO
这是 test.sql,该脚本通过执行该类型测试该示例。
USE AdventureWorks;
GO
-- simple usage of the type in variables and select statements
-- convert to string, binary, do a substring on it, get the utf8bytes
DECLARE @u Utf8String;
SET @u = CONVERT(Utf8String, 'hello world');
SELECT @u.ToString(),
CONVERT(varbinary(8000), @u),
SUBSTRING(@u.ToString(), 1, 5),
@u.Utf8Bytes;
GO
-- create a table with this type
CREATE TABLE utf8test(u Utf8String);
GO
-- populate it with some random data
SET NOCOUNT ON;
BEGIN TRAN;
DECLARE @index int, @str nvarchar(4000);
SET @index = 0;
WHILE @index < 1000
BEGIN
SET @str = CONVERT(nvarchar(100), @index);
INSERT INTO utf8test VALUES(CONVERT(Utf8String, @str))
SET @index = @index + 1;
END
COMMIT TRAN;
GO
-- Find a particular UTF8 string
DECLARE @i int;
SELECT @i = COUNT(*) from utf8test
WHERE u = CONVERT(Utf8String, '100');
SELECT @i;
go
-- Find UTF8 strings with a particular substring
DECLARE @i int;
SELECT @i = COUNT(*) from utf8test
WHERE SUBSTRING(u.ToString(), 1, 1) = '1';
SELECT @i;
GO
-- Add a computed column over the ToString method
ALTER TABLE utf8test ADD ustr AS u.ToString() PERSISTED;
GO
-- Create an index over the computed column
CREATE INDEX IX_utf8test_ustr ON utf8test(ustr);
GO
-- Binary comparisons on Utf8Strings are not effective. Even if we use the ToString method
-- to convert it to a string, we may want to have more control over whether case, width, or
-- attributes are relevant to the comparison. This portion of the test creates a table of
-- localized data pulled from the resumes stored in the AdventureWorks database,
-- and then demonstrates comparsions and sorting based on the CompareUsingCulture
-- and GetSortKeyUsingCulture methods defined on Utf8String.
IF EXISTS (SELECT * FROM sys.objects WHERE ([name] = N'ResumeFullName') AND ([type] = 'FN'))
DROP FUNCTION [dbo].[ResumeFullName];
GO
-- Returns the complete name of the applicant from her resume.
-- We don't just use data(/RES:Resume[1]/RES:Name) because we need spaces
-- between each part of the name.
CREATE FUNCTION ResumeFullName (@Resume xml)
RETURNS nvarchar(100)
AS
BEGIN
RETURN CONVERT(nvarchar(100), @Resume.query(N'declare namespace RES="https://schemas.microsoft.com/sqlserver/2004/07/adventure-works/Resume"; for $b in /RES:Resume[1]/RES:Name/* return data($b)'));
END
GO
SELECT Cast(RTRIM(LTRIM(dbo.ResumeFullName(Resume))) as Utf8String) AS FullName
INTO ResumeNames FROM HumanResources.JobCandidate;
GO
SELECT FullName.ToString() FROM ResumeNames;
DECLARE @Shai Utf8String;
SET @Shai = N'Shai Bassli';
SELECT FullName.ToString() FROM ResumeNames
WHERE FullName.CompareUsingCulture(@Shai, 'en-us', 1, 0, 0) = 0;
GO
ALTER TABLE ResumeNames ADD SortKey AS FullName.GetSortKeyUsingCulture('en-us', 1, 0, 0) PERSISTED;
GO
CREATE INDEX IX_ResumeNames_SortKey ON ResumeNames(SortKey);
GO
SELECT FullName.ToString()
FROM ResumeNames
ORDER BY SortKey;
下面的 Transact-SQL 从数据库中删除程序集和类型。
USE AdventureWorks;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE ([name] = N'ResumeFullName') AND ([type] = 'FN'))
DROP FUNCTION [dbo].[ResumeFullName];
GO
IF EXISTS (SELECT * FROM sys.indexes WHERE NAME = N'IX_utf8test_ustr')
DROP INDEX utf8test.IX_utf8test_ustr;
GO
IF EXISTS (SELECT * FROM sys.tables WHERE name = N'utf8test')
DROP TABLE [dbo].[utf8test];
GO
IF EXISTS (SELECT * FROM sys.tables WHERE name = N'ResumeNames')
DROP TABLE [dbo].[ResumeNames];
GO
IF EXISTS (SELECT * FROM sys.types WHERE name = N'Utf8String')
DROP TYPE [Utf8String];
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'UTF8String')
DROP ASSEMBLY UTF8String;
GO