Sqlite 参数化 模糊查询 解决方案

转自：https://codedefault.com/2018/does-dapper-support-the-like-operator-in-csharp-application

问题描述

如题，在.NET/C#的程序开发中，使用Dapper查询数据时，如何实现类似SQL查询语句中的like操作，如：

var data = conn.Query(@"
    select top 25
    Term as Label,
    Type,
    ID
    from SearchTerms
    WHERE Term like '%@T%'",
    new { T = (string)term });

以上的语句执行后的结果是错误的，在Dapper中，类似SQL语句中的like应该如何处理呢？

方案一

term = "whateverterm";
var encodeForLike = term => term.Replace("[", "[[]").Replace("%", "[%]");

string term = "%" + encodeForLike(term) + "%";
var data = conn.Query(@"
   select top 25
  Term as Label,
  Type,
  ID
  from SearchTerms
  WHERE Term like @term",
  new { term });

方案二

string query = "SELECT * from country WHERE Name LIKE CONCAT('%',@name,'%');"
var results = connection.query<country>(query, new {name});

方案三

db.Query<Remitente>("SELECT *
                     FROM Remitentes
                     WHERE Nombre LIKE @n", new { n = "%" + nombre + "%" })
                   .ToList();