将 varchar 转换为数据类型 int: SQL 时转换失败

Question

我正在 asp.net mvc 中创建一个 Web 应用程序，我有一个如下所示的查询

using (SqlConnection conn = new SqlConnection(_connStr))
{
conn.Open();
var p = new DynamicParameters();
p.Add("@SP_RoleId", "7,8,9", dbType: DbType.String, direction: ParameterDirection.Input);
p.Add("@SP_UserId", userId, dbType: DbType.Int32, direction: ParameterDirection.Input);
var obj = conn.Query<PendingKmsRequest>(sql: "SELECT [f].[id] AS [FileId],[fvr].[Id] AS [RequestId], [au].[Name]"
+ ", [fvr].[RequestByUserId], [fvr].[FromDate], [fvr].[ToDate],[f].[Title], [fvr].[Status], [fvr].[StatusRemarks]"
+ "FROM [dbo].[File] AS[f]"
+ "INNER JOIN [dbo].[FileViewRequest] AS [fvr] ON [f].[CurrentFileVersionId] = [fvr].[FileVersionId]"
+ "INNER JOIN [Access].[User] AS [au] ON [fvr].[RequestByUserId] = [au].[Id]"
+ "WHERE ([fvr].[Status] = 'P' OR ([fvr].[Status] = 'A' AND [fvr].[StatusByUserId] = @SP_UserId AND GETDATE() BETWEEN [fvr].[FromDate] AND [fvr].[ToDate]))"
+ "AND (SELECT 1 FROM [Access].[UserRoleMap] WHERE UserId=@SP_UserId AND RoleId IN(@SP_RoleId)) = 1", param: p, commandType: CommandType.Text);
if (obj != null && obj.Count() > 0)
return obj.ToList();
else
return new List<PendingKmsRequest>();
}

注意：角色 ID 始终类似于 (7,8,9)，并且是数据库中int列。

我在这行代码上收到此转换错误：

WHERE UserId = @SP_UserId AND RoleId IN (@SP_RoleId))

这是错误：

将 nvarchar 值"7,9,10"转换为数据类型 int 时转换失败。

如何防止此错误？

Answer 1

问题代码中的以下行：

p.Add("@SP_RoleId", "7,8,9", dbType: DbType.String, direction: ParameterDirection.Input);

值"7,8,9"是字符串，参数类型DbType.String也是字符串。

但是，你说这在你的数据库中int。这是不匹配的。

此外，您的查询：

WHERE UserId = @SP_UserId AND RoleId IN (@SP_RoleId))

查询正在使用IN子句。

如果传入IEnumerable，Dapper 可以转换IN子句的值。

更改代码行，如下所示：

p.Add("@SP_RoleId", new[] {7,8,9}, dbType: DbType.Int32, direction: ParameterDirection.Input);

Answer 2

无需在array中使用转换字符串或任何字符串split()函数

如果您有逗号分隔字符串，则可以按照以下步骤进行检查，

1. 如果您有@SP_RoleId = "7, 8, 9"
2. 您可以按如下
   方式转换此字符串@SP_RoleId = ",7,8,9,"(',' + ltrim(rtrim( @SP_RoleId )) + ',')
3. 现在使用Like来检查,UserId,

更新的代码如下，

using (SqlConnection conn = new SqlConnection(_connStr))
{
conn.Open();
var p = new DynamicParameters();
p.Add("@SP_RoleId", "7,8,9", dbType: DbType.String, direction: ParameterDirection.Input);
p.Add("@SP_UserId", userId, dbType: DbType.Int32, direction: ParameterDirection.Input);
var obj = conn.Query<PendingKmsRequest>(sql: "SELECT [f].[id] AS [FileId],[fvr].[Id] AS [RequestId], [au].[Name]"
+ ", [fvr].[RequestByUserId], [fvr].[FromDate], [fvr].[ToDate],[f].[Title], [fvr].[Status], [fvr].[StatusRemarks]"
+ "FROM [dbo].[File] AS[f]"
+ "INNER JOIN [dbo].[FileViewRequest] AS [fvr] ON [f].[CurrentFileVersionId] = [fvr].[FileVersionId]"
+ "INNER JOIN [Access].[User] AS [au] ON [fvr].[RequestByUserId] = [au].[Id]"
+ "WHERE ([fvr].[Status] = 'P' OR ([fvr].[Status] = 'A' AND [fvr].[StatusByUserId] = @SP_UserId AND GETDATE() BETWEEN [fvr].[FromDate] AND [fvr].[ToDate]))"
+ "AND (SELECT 1 FROM [Access].[UserRoleMap] WHERE ',' +  lTrim(rTrim(@SP_RoleId)) + ',' like '%,' + lTrim(rTrim(UserId) + ',%' " // Updated line
+ "AND RoleId IN(@SP_RoleId)) = 1", param: p, commandType: CommandType.Text);
if (obj != null && obj.Count() > 0)
return obj.ToList();
else
return new List<PendingKmsRequest>();
}