如何使用C#将pdf文件插入和读取到Sql Server 数据库

CREATE TABLE PdfFiles (
    Id INT PRIMARY KEY IDENTITY(1,1),
    FileName NVARCHAR(MAX),
    Content VARBINARY(MAX)
);

using iTextSharp.text.pdf;
using System.IO;

public byte[] ConvertPdfToByteArray(string pdfPath)
{
    byte[] pdfBytes;
    using (var pdfReader = new PdfReader(pdfPath))
    {
        using var memoryStream = new MemoryStream();
        using var pdfStamper = new PdfStamper(pdfReader, memoryStream);
        pdfStamper.Close();
        pdfBytes = memoryStream.ToArray();
    }
    return pdfBytes;
}

using System.Data.SqlClient;

public void InsertPdfIntoDatabase(string pdfPath, string fileName, string connectionString)
{
    byte[] pdfBytes = ConvertPdfToByteArray(pdfPath);

    using var connection = new SqlConnection(connectionString);
    connection.Open();

    using var command = new SqlCommand("INSERT INTO PdfFiles (FileName, Content) VALUES (@FileName, @Content)", connection);
    command.Parameters.AddWithValue("@FileName", fileName);
    command.Parameters.AddWithValue("@Content", pdfBytes);
    command.ExecuteNonQuery();
}

using System.Data.SqlClient;
using System.IO;

public void ReadPdfFromDatabase(int pdfId, string outputPath, string connectionString)
{
    using var connection = new SqlConnection(connectionString);
    connection.Open();

    using var command = new SqlCommand("SELECT Content FROM PdfFiles WHERE Id = @Id", connection);
    command.Parameters.AddWithValue("@Id", pdfId);

    using var reader = command.ExecuteReader();
    if (reader.Read())
    {
        byte[] pdfBytes = (byte[])reader["Content"];

        using var pdfReader = new PdfReader(pdfBytes);
        using var pdfStamper = new PdfStamper(pdfReader, new FileStream(outputPath, FileMode.Create));
        pdfStamper.Close();
    }
}