C#：SQL 查询生成器类

Question

我在哪里可以找到一个好的 SQL 查询构建器类。我只需要一个简单的类来构建一个 SQL 字符串，就是这样。我将需要它用于 C# 和 MySql。我真的不需要像 Linq 或 NHibernate 这样的东西。谢谢

Answer 1

您可能可以使用框架类 CommandBuilder。签出：

http://msdn.microsoft.com/en-us/library/tf579hcz.aspx

Answer 2

如果您使用 .NET 4 并且不介意使用动态，您可以使用由 Rob Conery 创建的 Massive，这个单文件数据库不需要 dll，只需删除 Massive.cs 文件即可开始使用。

您可以使用 Massive 来构建这样的查询。

//grab all the products
var products = table.All();
//Or
var productsFour = table.All(columns: "ProductName as Name", where: "WHERE categoryID=@0",args: 4);

您还可以根据需要运行临时查询：

var result = tbl.Query("SELECT * FROM Categories");

Answer 3

我使用这个代码..它也转义了字符串我希望它有帮助：

 class Mysql
{
    public static string INSERT(string INTO, NameValueCollection VALUES)
    {
        string queryString = "INSERT INTO " + INTO + " (";
        for (int i = 0; i < VALUES.Count; i++)
        {
            queryString += VALUES.Keys[i] + (i + 1 == VALUES.Count ? "" : ",");
        }
        queryString += ") VALUES (";

        for (int i = 0; i < VALUES.Count; i++)
        {
            queryString += Escape(VALUES[VALUES.Keys[i]]) + (i + 1 == VALUES.Count ? ("") : (","));
        }
        queryString += ");";
        return queryString;
    }
    public static string DELETE(string FROM, NameValueCollection WHERE)
    {

        string queryString = "DELETE FROM " + FROM + " WHERE";
        for (int i = 0; i < WHERE.Count; i++)
        {
            queryString += " " + WHERE.Keys[i] + "=" + Escape(WHERE[WHERE.Keys[i]]);

        }

        queryString += ";";
        return queryString;
    }
    public static string UPDATE(string UPDATE, NameValueCollection SET, NameValueCollection WHERE)
    {

        string queryString = "UPDATE " + UPDATE + " SET";
        for (int i = 0; i < SET.Count; i++)
        {
            queryString += " " + SET.Keys[i] + "=" + data.Escape(SET[SET.Keys[i]]) + (i + 1 == SET.Count ? ("") : (","));

        }
        queryString += " WHERE";
        for (int i = 0; i < WHERE.Count; i++)
        {
            queryString += " " + WHERE.Keys[i] + "=" + data.Escape(WHERE[WHERE.Keys[i]]);

        }
        queryString += ";";
        return queryString;

    }
    public static string SELECT(string[] SELECT, string FROM, NameValueCollection WHERE)
    {

        string queryString = "SELECT ";

        for (int i = 0; i < SELECT.Length; i++)
        {
            queryString += SELECT[i] + (i + 1 == SELECT.Length ? ("") : (","));

        }
        queryString += " FROM " + FROM + " WHERE ";
        for (int i = 0; i < WHERE.Count; i++)
        {
            queryString += " " + WHERE.Keys[i] + "=" + Escape(WHERE[WHERE.Keys[i]]);

        }

        queryString += ";";
        return queryString;

    }
    public static string Escape(string input)
    {
        using (var writer = new StringWriter())
        {
            using (var provider = CodeDomProvider.CreateProvider("CSharp"))
            {
                provider.GenerateCodeFromExpression(new CodePrimitiveExpression(input), writer, null);
                return writer.ToString();
            }
        }
    }
}

你可以这样使用它：

        NameValueCollection nvc_for_SET_and_VALUES=new NameValueCollection();
        NameValueCollection nvc_for_WHERE= new NameValueCollection();
        nvc_for_WHERE.Add("arg1","value1");
        nvc_for_WHERE.Add("AND arg2","value2");
        nvc_for_WHERE.Add("OR arg2","value3");
        nvc_for_SET_and_VALUES.Add("arg", "value");
        nvc_for_SET_and_VALUES.Add("arg2", "value2");
        string[] fieldsToSelect= { "arg1", "arg2" };
        Mysql.DELETE("mytable", nvc_for_WHERE);
        Mysql.INSERT("mytable", nvc_for_SET_and_VALUES);
        Mysql.SELECT(fieldsToSelect, "mytable", nvc_for_WHERE);
        Mysql.UPDATE("mytable", nvc_for_SET_and_VALUES, nvc_for_WHERE);

Answer 4

Mohammed Hadi，DbExtensions 您的样本可以是这样的：

    public static string InsertQuery(string into, NameValueCollection values)
    {
        var query = SQL
            .INSERT_INTO(into + " (" +
                         String.Join(" ,", values.Keys.Cast<String>().ToArray()) + 
                         ")")
            .VALUES(values.Keys.Cast<String>().Select(key => values[key]));

        return query.ToString();
    }

Answer 5

由于 Google 将我引导至此页面， 我建议SqlKata，一个简单但功能强大的 SqlQuery Builder，它支持嵌套 where 条件、子查询和连接。

目前支持SqlServer、MySql和PostgreSql

var query = new Query("Users")
     .LeftJoin("Countries", "Users.CountryId", "Countries.Id")
     .Where("Status", "blocked")
     .OrWhereIn("Id", new [] {10, 11, 12})
     .OrWhere("LastLogin", ">", DateTime.UtcNow.AddMonths(-5));

注意：我是它的所有者

不同编译器输出的区别
MySql:https://sqlkata.com/playground/mysql?code=var%20query%20=%20new%20Query(%22Posts%22).Limit(10).Offset(20)%3B

SqlServer： https://sqlkata.com/playground/sqlserver?code=var%20query%20=%20new%20Query(%22Posts%22).Limit(10).Offset(20)%3B

甲骨文： https://sqlkata.com/playground/oracle?code=var%20query%20=%20new%20Query(%22Posts%22).Limit(10).Offset(20)%3B