feat(etl): implement DbBulkImportDestination for full table refresh

Add bulk import destination that truncates and loads data using SqlBulkCopy with configurable batch sizes and streaming support.
2026-01-03 09:22:57 -05:00
parent 8594baf11d
commit 63a0e7cf7e
3 changed files with 147 additions and 0 deletions
@@ -0,0 +1,99 @@
+using System.Data;
+using System.Diagnostics;
+using JdeScoping.DataAccess.Interfaces;
+using JdeScoping.DataSync.Etl.Contracts;
+using JdeScoping.DataSync.Etl.Results;
+using Microsoft.Data.SqlClient;
+
+namespace JdeScoping.DataSync.Etl.Destinations;
+
+/// <summary>
+/// Imports data into a SQL Server table using bulk copy operations.
+/// Performs a full table refresh by truncating the table before loading.
+/// </summary>
+public class DbBulkImportDestination : IImportDestination
+{
+    private const int DefaultBatchSize = 10000;
+
+    private readonly IDbConnectionFactory _connectionFactory;
+    private readonly string _tableName;
+    private readonly int _batchSize;
+
+    /// <inheritdoc />
+    public string DestinationName => $"BulkImport:{_tableName}";
+
+    /// <summary>
+    /// Creates a new bulk import destination for the specified table.
+    /// </summary>
+    /// <param name="connectionFactory">Factory to create database connections.</param>
+    /// <param name="tableName">Name of the destination table.</param>
+    /// <param name="batchSize">Number of rows per batch. 0 uses the default (10000).</param>
+    public DbBulkImportDestination(
+        IDbConnectionFactory connectionFactory,
+        string tableName,
+        int batchSize = 0)
+    {
+        ArgumentNullException.ThrowIfNull(connectionFactory);
+        ArgumentException.ThrowIfNullOrWhiteSpace(tableName);
+
+        _connectionFactory = connectionFactory;
+        _tableName = tableName;
+        _batchSize = batchSize > 0 ? batchSize : DefaultBatchSize;
+    }
+
+    /// <inheritdoc />
+    public async Task<DestinationResult> WriteAsync(
+        IDataReader source,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(source);
+
+        var stopwatch = Stopwatch.StartNew();
+        long totalRows = 0;
+        int batchCount = 0;
+
+        await using var connection = await _connectionFactory.CreateLotFinderConnectionAsync(cancellationToken);
+
+        // Truncate destination table
+        await using (var truncateCmd = connection.CreateCommand())
+        {
+            truncateCmd.CommandText = $"TRUNCATE TABLE [{_tableName}]";
+            await truncateCmd.ExecuteNonQueryAsync(cancellationToken);
+        }
+
+        // Bulk copy data
+        using var bulkCopy = new SqlBulkCopy(connection)
+        {
+            DestinationTableName = $"[{_tableName}]",
+            BatchSize = _batchSize,
+            BulkCopyTimeout = 3600,
+            EnableStreaming = true
+        };
+
+        // Map columns by name
+        for (int i = 0; i < source.FieldCount; i++)
+        {
+            bulkCopy.ColumnMappings.Add(source.GetName(i), source.GetName(i));
+        }
+
+        // Track rows via event
+        bulkCopy.NotifyAfter = _batchSize;
+        bulkCopy.SqlRowsCopied += (_, e) =>
+        {
+            totalRows = e.RowsCopied;
+            batchCount++;
+        };
+
+        await bulkCopy.WriteToServerAsync(source, cancellationToken);
+
+        // Final count - RowsCopied property may have more rows if NotifyAfter didn't fire
+        if (bulkCopy.RowsCopied > totalRows)
+        {
+            totalRows = bulkCopy.RowsCopied;
+            batchCount++;
+        }
+
+        stopwatch.Stop();
+        return new DestinationResult(totalRows, batchCount, stopwatch.Elapsed);
+    }
+}