sql-server - SQL Server Reporting Services - 报表表达式执行

Question

假设我有以下表达式：

=DateAdd(DateInterval.Year,-1,Today())

是否有允许我传入表达式并返回执行表达式的结果的 SQL Server Web 服务端点？我查看了此处列出的端点，但找不到。

还是有另一种方法来评估这个表达式？

标签： sql-serverreporting-services

Answer 1

我找到了另一种使用 VB.net 评估表达式的方法（假设@Wolfgang Kais 关于使用 VB.net 而不是 VBA 是正确的）

这是代码片段：

using System;
using System.CodeDom.Compiler;
using System.Text;
using Microsoft.VisualBasic;

namespace VbStringCompiler
{
internal class Program
{
    public static void Main(string[] args)
    {
        new Program();
    }

    private const string CRLF = "\r\n";

    private Program()
    {
        var vbCodeProvider = new VBCodeProvider();

        var compilerParameters = new CompilerParameters();
        compilerParameters.ReferencedAssemblies.Add("Microsoft.VisualBasic.dll");
        compilerParameters.ReferencedAssemblies.Add("System.dll");
        compilerParameters.CompilerOptions = "/t:library";
        compilerParameters.GenerateInMemory = true;

        var stringBuilder = new StringBuilder();

        stringBuilder.Append("Imports Microsoft.VisualBasic" + CRLF);
        stringBuilder.Append("Imports System" + CRLF + CRLF);

        stringBuilder.Append("Namespace Evaluate" + CRLF);
        stringBuilder.Append("Class RunTime" + CRLF);
        stringBuilder.Append("Public Function Run() As Object" + CRLF);

        // insert code to return
        stringBuilder.Append("Return DateAdd(DateInterval.Year, -1, Today())" + CRLF);

        stringBuilder.Append("End Function" + CRLF);
        stringBuilder.Append("End Class" + CRLF);
        stringBuilder.Append("End Namespace" + CRLF);

        try
        {
            var compilerResults =
                vbCodeProvider.CompileAssemblyFromSource(compilerParameters, stringBuilder.ToString());
            if (compilerResults.Errors.Count > 0)
            {
                foreach (CompilerError compilerError in compilerResults.Errors)
                {
                    Console.Error.WriteLine(compilerError.ToString());
                }

                return;
            }

            var instance = compilerResults.CompiledAssembly.CreateInstance("Evaluate.RunTime");
            var methodInfo = instance.GetType().GetMethod("Run");
            var methodReturn = methodInfo.Invoke(instance, null);

            Console.WriteLine(methodReturn);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.StackTrace);
        }
    }
}
}