如何在加密列中插入 NULL/empty 字符串 - Always Encrypted

Question

我已经使用 SQL Server 2016 always encrypt 方法加密了现有数据，我们拥有的列之一是 NULLABLE，但是从屏幕插入时它不接受 NULL 或空字符串。如果加密列在屏幕上不是必需的，如何让它工作？

Answer 1

您看到的错误是不正确的，请确保您正确传递了参数。以下是有关如何执行此操作的一些示例代码。

架构：

CREATE TABLE [dbo].[SO](
    [ssn] [nvarchar](9) COLLATE Latin1_General_BIN2 ENCRYPTED WITH (COLUMN_ENCRYPTION_KEY = [CEK_Auto1], ENCRYPTION_TYPE = Deterministic, ALGORITHM = 'AEAD_AES_256_CBC_HMAC_SHA_256') NULL
)

GO

CREATE PROCEDURE dbo.insertSP @ssn nvarchar(9)
AS

INSERT INTO [dbo].[SO] ([SSN]) VALUES (@SSN);
GO

C#代码：

        SqlConnectionStringBuilder strbldr = new SqlConnectionStringBuilder();
        strbldr.DataSource = ".";
        strbldr.InitialCatalog = @"exptdb";
        strbldr.IntegratedSecurity = true;
        strbldr.ColumnEncryptionSetting = SqlConnectionColumnEncryptionSetting.Enabled;

        string ssn = "";

        using (var conn = new SqlConnection(strbldr.ConnectionString))
        using (var command = conn.CreateCommand()) {

            command.CommandType = CommandType.StoredProcedure;
            command.CommandText = @"dbo.insertSP";

            SqlParameter paramSSN = command.CreateParameter();
            paramSSN.ParameterName = "@ssn";
            paramSSN.SqlDbType = SqlDbType.NVarChar;
            paramSSN.Direction = ParameterDirection.Input;
            paramSSN.Value = ssn;
            paramSSN.Size = 9;
            command.Parameters.Add(paramSSN);

            conn.Open();
            command.ExecuteNonQuery();
        }

注意，即在上述场景中，如果

string ssn = "";

则查询成功，但是如果

string ssn = null;

你应该看到执行失败

Additional information: Procedure or function 'insertSP' expects parameter '@ssn', which was not supplied.

即使 ssn 列为明文也会出现此故障

您可以按如下方式在加密列中插入空值，因为空值未加密：

        using (var conn = new SqlConnection(strbldr.ConnectionString))
        using (var command = conn.CreateCommand()) {

            command.CommandText = @"INSERT INTO [dbo].[SO] ([SSN]) VALUES (null)";

            conn.Open();
            command.ExecuteNonQuery();
        }

如何在加密列中插入 NULL/empty 字符串 - Always Encrypted

How to insert NULL/empty string in encrypted column - Always Encrypted

sql-server

always-encrypted