使用C#配置信息类的属性生成Snowflake CREATE STAGE语句

using System;
using System.Collections.Generic;
using System.Linq;

public class StageConfig
{
    public string Name { get; set; }
    public bool Replace { get; set; }
    public bool IfNotExists { get; set; }
    public string StorageIntegration { get; set; }
    public string Url { get; set; }
    public string Credentials { get; set; }
    public FileFormatOptions FileFormat { get; set; }
    public Dictionary<string, string> CopyOptions { get; set; }
    public string Comment { get; set; }
}

public class FileFormatOptions
{
    public string FormatName { get; set; }
    public string Type { get; set; }
    public Dictionary<string, string> FormatOptions { get; set; } = new Dictionary<string, string>();
}

public class StageSqlGenerator
{
    public static string GenerateCreateStageSql(StageConfig config)
    {
        var replaceModifier = config.Replace ? "OR REPLACE " : "";
        var ifNotExistsModifier = config.IfNotExists ? "IF NOT EXISTS " : "";
        var clauses = new List<string>();

        AddStorageIntegration(config, clauses);
        AddUrl(config, clauses);
        AddCredentials(config, clauses);
        AddFileFormat(config, clauses);
        AddCopyOptions(config, clauses);
        AddComment(config, clauses);

        return FormatFinalSql(config, replaceModifier, ifNotExistsModifier, clauses);
    }

    private static void AddStorageIntegration(StageConfig config, List<string> clauses)
    {
        if (!string.IsNullOrEmpty(config.StorageIntegration))
        {
            clauses.Add($"STORAGE_INTEGRATION = {config.StorageIntegration}");
        }
    }

    private static void AddUrl(StageConfig config, List<string> clauses)
    {
        if (!string.IsNullOrEmpty(config.Url))
        {
            clauses.Add($"URL = '{EscapeSqlString(config.Url)}'");
        }
    }

    private static void AddCredentials(StageConfig config, List<string> clauses)
    {
        if (!string.IsNullOrEmpty(config.Credentials))
        {
            clauses.Add($"CREDENTIALS = ( {config.Credentials} )");
        }
    }

    private static void AddFileFormat(StageConfig config, List<string> clauses)
    {
        if (config.FileFormat == null) return;

        var ff = config.FileFormat;
        if (!string.IsNullOrEmpty(ff.FormatName))
        {
            clauses.Add($"FILE_FORMAT = ( FORMAT_NAME = '{EscapeSqlString(ff.FormatName)}' )");
        }
        else if (!string.IsNullOrEmpty(ff.Type))
        {
            var typeClause = $"TYPE = {ff.Type}";
            var options = ff.FormatOptions.Select(kv => $"{kv.Key} = {kv.Value}");
            clauses.Add(options.Any()
                ? $"FILE_FORMAT = ( {typeClause}, {string.Join(", ", options)} )"
                : $"FILE_FORMAT = ( {typeClause} )");
        }
    }

    private static void AddCopyOptions(StageConfig config, List<string> clauses)
    {
        if (config.CopyOptions?.Any() != true) return;
        
        var copyOptions = config.CopyOptions
            .Select(kv => $"{kv.Key} = {kv.Value}");
        clauses.Add($"COPY_OPTIONS = ( {string.Join(", ", copyOptions)} )");
    }

    private static void AddComment(StageConfig config, List<string> clauses)
    {
        if (!string.IsNullOrEmpty(config.Comment))
        {
            clauses.Add($"COMMENT = '{EscapeSqlString(config.Comment)}'");
        }
    }

    private static string FormatFinalSql(StageConfig config, string replaceModifier, 
        string ifNotExistsModifier, List<string> clauses)
    {
        return $"CREATE {replaceModifier}STAGE {ifNotExistsModifier}{config.Name}" +
               (clauses.Any() 
                   ? $"\n  {string.Join("\n  ", clauses)};" 
                   : ";");
    }

    private static string EscapeSqlString(string input)
    {
        return input?.Replace("'", "''") ?? string.Empty;
    }
}

// 使用示例
public class Program
{
    public static void Main()
    {
        var config = new StageConfig
        {
            Name = "my_s3_stage",
            Replace = true,
            Url = "s3://mybucket/path/",
            Credentials = "AWS_KEY_ID='AKIAXXX' AWS_SECRET_KEY='XXX'",
            FileFormat = new FileFormatOptions
            {
                Type = "CSV",
                FormatOptions = new Dictionary<string, string>
                {
                    { "FIELD_DELIMITER", "','" },
                    { "SKIP_HEADER", "1" }
                }
            },
            CopyOptions = new Dictionary<string, string>
            {
                { "ON_ERROR", "'CONTINUE'" }
            },
            Comment = "Production stage for customer data"
        };

        var sql = StageSqlGenerator.GenerateCreateStageSql(config);
        Console.WriteLine(sql);
    }
}

生成的SQL语句示例：

CREATE OR REPLACE STAGE my_s3_stage
  URL = 's3://mybucket/path/'
  CREDENTIALS = ( AWS_KEY_ID='AKIAXXX' AWS_SECRET_KEY='XXX' )
  FILE_FORMAT = ( TYPE = CSV, FIELD_DELIMITER = ',', SKIP_HEADER = 1 )
  COPY_OPTIONS = ( ON_ERROR = 'CONTINUE' )
  COMMENT = 'Production stage for customer data';

实现说明：

1. 配置类结构 ：StageConfig包含所有可能的阶段配置参数，FileFormatOptions专门处理文件格式配置
2. SQL生成逻辑 ：
   • 自动处理OR REPLACE和IF NOT EXISTS修饰符
   • 按正确顺序拼接各个配置参数
   • 自动处理单引号转义
   • 支持嵌套的文件格式和复制选项配置
3. 扩展性：采用模块化设计，每个配置部分有独立的处理方法，方便后续扩展
4. 格式处理：自动格式化生成的SQL语句，保持Snowflake SQL规范风格
5. 安全处理：对字符串值进行基本的SQL注入防护（单引号转义）