Question

我在名为UserFunctions.dll的程序集dll中有几个函数，例如：

public static partial class VariousFunctions
{
    [SqlFunction(IsDeterministic = true, IsPrecise = true)]
    public static SqlBoolean RegexMatch(SqlString expression, SqlString pattern)
    {
      ...
    }

    [SqlFunction(IsDeterministic = true, IsPrecise = true)]
    public static SqlInt32 WorkingDays(SqlDateTime startDateTime, SqlDateTime endDateTime)
    {
      ...
    }

    [SqlFunction(IsDeterministic = true, IsPrecise = true)]
    public static SqlString getVersion()
    {
      ...
    }

    ...
}

我想生成带有c＃函数的sql脚本，以自动创建或更新此dll中包含的属性SqlFunction的所有函数。这个sql脚本应如下所示：

-- Delete all functions from assembly 'UserFunctions'
DECLARE @sql NVARCHAR(MAX)
SET @sql = 'DROP FUNCTION ' + STUFF(
            (
                SELECT
                    ', ' + QUOTENAME(assembly_method) 
                FROM
                    sys.assembly_modules
                WHERE
                    assembly_id IN (SELECT assembly_id FROM sys.assemblies WHERE name = 'UserFunctions')
                FOR XML PATH('')
            ), 1, 1, '')
-- SELECT @sql
IF @sql IS NOT NULL EXEC sp_executesql @sql


-- Create all functions from assembly 'UserFunctions'
CREATE FUNCTION RegexMatch(@expression NVARCHAR(MAX), @pattern NVARCHAR(MAX)) RETURNS BIT 
    AS EXTERNAL NAME UserFunctions.VariousFunctions.RegexMatch;
GO
CREATE FUNCTION WorkingDays(@startDateTime DATETIME, @endDateTime DATETIME) RETURNS INTEGER 
    AS EXTERNAL NAME UserFunctions.VariousFunctions.WorkingDays;
GO  
 CREATE FUNCTION getVersion() RETURNS VARCHAR(MAX) 
    AS EXTERNAL NAME UserFunctions.VariousFunctions.getVersion;
GO

第一部分非常简单，但对于第二部分，可能使用类Type，MethodInfo和ParameterInfo的反射方法。有人已经这样做了吗？

Answer 1

我已经测试并调试过它：

static void Main(string[] args)
{
  Assembly clrAssembly = Assembly.LoadFrom(@"Path\to\your\assembly.dll");
  string sql = CreateFunctionsFromAssembly(clrAssembly, permissionSetType.UNSAFE);
  File.WriteAllText(sqlFile, sql);
}


/// <summary>
/// permissions available for an assembly dll in sql server
/// </summary>
public enum permissionSetType { SAFE, EXTERNAL_ACCESS, UNSAFE };


/// <summary>
/// generate sql from an assembly dll with all functions with attribute SqlFunction
/// </summary>
/// <param name="clrAssembly">assembly object</param>
/// <param name="permissionSet">sql server permission set</param>
/// <returns>sql script</returns>
public static string CreateFunctionsFromAssembly(Assembly clrAssembly, permissionSetType permissionSet)
{
    const string sqlTemplate = @"
      -- Delete all functions from assembly '{0}'
      DECLARE @sql NVARCHAR(MAX)
      SET @sql = 'DROP FUNCTION ' + STUFF(
        (
            SELECT
                ', ' + assembly_method 
            FROM
                sys.assembly_modules
            WHERE
                assembly_id IN (SELECT assembly_id FROM sys.assemblies WHERE name = '{0}')
            FOR XML PATH('')
        ), 1, 1, '')
      IF @sql IS NOT NULL EXEC sp_executesql @sql
      GO

      -- Delete existing assembly '{0}' if necessary
      IF EXISTS(SELECT 1 FROM sys.assemblies WHERE name = '{0}')
        DROP ASSEMBLY {0};
      GO

      {1}
      GO

      -- Create all functions from assembly '{0}'
    ";
    string assemblyName = clrAssembly.GetName().Name;

    StringBuilder sql = new StringBuilder();
    sql.AppendFormat(sqlTemplate, assemblyName, CreateSqlFromAssemblyDll(clrAssembly, permissionSet));

    foreach (Type classInfo in clrAssembly.GetTypes())
    {
        foreach (MethodInfo methodInfo in classInfo.GetMethods(BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly))
        {
            if (Attribute.IsDefined(methodInfo, typeof(SqlFunctionAttribute)))
            {
                StringBuilder methodParameters = new StringBuilder();
                bool firstParameter = true;
                foreach (ParameterInfo paramInfo in methodInfo.GetParameters())
                {
                    if (firstParameter)
                         firstParameter = false;
                    else
                        methodParameters.Append(", ");
                    methodParameters.AppendFormat(@"@{0} {1}", paramInfo.Name, ConvertClrTypeToSql(paramInfo.ParameterType));
                }
                string returnType = ConvertClrTypeToSql(methodInfo.ReturnParameter.ParameterType);
                string methodName = methodInfo.Name;
                string className = (classInfo.Namespace == null ? "" : classInfo.Namespace + ".") + classInfo.Name;
                string externalName = string.Format(@"{0}.[{1}].{2}", assemblyName, className, methodName);
                sql.AppendFormat(@"CREATE FUNCTION {0}({1}) RETURNS {2} AS EXTERNAL NAME {3};"
                                , methodName, methodParameters, returnType, externalName)
                   .Append("\nGO\n");
            }
        }
    }
    return sql.ToString();
}


/// <summary>
/// Generate sql script to create assembly
/// </summary>
/// <param name="clrAssembly"></param>
/// <param name="permissionSet">sql server permission set</param>
/// <returns></returns>
public static string CreateSqlFromAssemblyDll(Assembly clrAssembly, permissionSetType permissionSet)
{
    const string sqlTemplate = @"
      -- Create assembly '{0}' from dll
      CREATE ASSEMBLY [{0}] 
        AUTHORIZATION [dbo]
        FROM 0x{2}
        WITH PERMISSION_SET = {1};
    ";

    StringBuilder bytes = new StringBuilder();
    using (FileStream dll = File.OpenRead(clrAssembly.Location))
    {
        int @byte;
        while ((@byte = dll.ReadByte()) >= 0)
            bytes.AppendFormat("{0:X2}", @byte);
    }
    string sql = String.Format(sqlTemplate, clrAssembly.GetName().Name, permissionSet, bytes);

    return sql;
}


/// <summary>
/// Convert clr type to sql type
/// </summary>
/// <param name="clrType">clr type</param>
/// <returns>sql type</returns>
private static string ConvertClrTypeToSql(Type clrType)
{
    switch (clrType.Name)
    {
        case "SqlString":
            return "NVARCHAR(MAX)";
        case "SqlDateTime":
            return "DATETIME";
        case "SqlInt16":
            return "SMALLINT";
        case "SqlInt32":
            return "INTEGER";
        case "SqlInt64":
            return "BIGINT";
        case "SqlBoolean":
            return "BIT";
        case "SqlMoney":
            return "MONEY";
        case "SqlSingle":
            return "REAL";
        case "SqlDouble":
            return "DOUBLE";
        case "SqlDecimal":
            return "DECIMAL(18,0)";
        case "SqlBinary":
            return "VARBINARY(MAX)";
        default:
            throw new ArgumentOutOfRangeException(clrType.Name + " is not a valid sql type.");
    }
}

Answer 2

一种方法可能是在已知函数中使用反射，该函数在dll中编译（如果是你的）或在你可以创建和引用的CLR dll中。在那里，您可以使用.NET的完全成熟的REGEX支持向SQL SERVER返回创建函数所需的匹配名称。

这是一种解决方法，但我不知道使用.NET反射的原生TSQL方法

<强> - 编辑 -

如果你需要从.NET创建一个TSQL脚本，你可以使用这样的东西（不活泼，但大多数东西应该在那里）

public string encode(Type containerClass, string SSRVassemblyName)
    {
        string proTSQLcommand="";
        MethodInfo[] methodName = containerClass.GetMethods();
        foreach (MethodInfo method in methodName)
        {
            proTSQLcommand += "CREATE FUNCTION ";
            if (method.ReflectedType.IsPublic)
            {
                bool hasParams = false;
                proTSQLcommand += method.Name +"(";
                ParameterInfo[] curmethodParams = method.GetParameters();
                if (curmethodParams.Length > 0)
                    for (int i = 0; i < curmethodParams.Length; i++)
                    {
                        proTSQLcommand +=(hasParams?",":"")+ String.Format("@{0} {1}",curmethodParams[i].Name,CLRtypeTranscoder(curmethodParams[i].ParameterType.Name)) ;
                        hasParams = true;
                    }
                proTSQLcommand += (hasParams ? "," : "") + String.Format("@RetVal {0} OUT", CLRtypeTranscoder(method.ReturnType.Name));

            }
            //note that I have moved the result of the function to an output parameter 
            proTSQLcommand += "RETURNS INT ";
            //watch this! the assembly name you have to use is the one of SSRV, to reference the one of the CLR library you have to use square brackets as follows
            proTSQLcommand += String.Format("AS EXTERNAL NAME {0}.[{1}.{2}].{3}; GO ",SSRVassemblyName, GetAssemblyName(containerClass.Name),containerClass.Name,method.Name);
        }
        return proTSQLcommand;
    }
    public string CLRtypeTranscoder(string CLRtype)
    { //required as the mapping of CLR type depends on the edition of SQL SERVER you are using
        switch (CLRtype.ToUpper())
        {
            case "STRING":
                return "VARCHAR(MAX)";
            case "INT":
                return "INT";
        }
        throw new   ArgumentOutOfRangeException();
    }
    public static String GetAssemblyName(String typeName)
    {
        foreach (Assembly currentassemblAssy in AppDomain.CurrentDomain.GetAssemblies())
        {
            Type t = currentassemblAssy.GetType(typeName, false, true);
            if (t != null) { return currentassemblAssy.FullName; }
        }

        return "not found";
    }