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Unable to perform BulkInsert into snowflake tables using dapper

Oct 21 2024 12:38 PM

Can anyone assist with performing BulkInsert and BulkUpdate operations on Snowflake tables using Dapper and C#. I am encountering issues where the values are not being inserted into the Snowflake tables. Any help would be greatly appreciated. Thanks in advance!
 

public async Task<int> BulkInsertAsync<T>(string tableName, IEnumerable<T> data, int batchSize = 1000)
{
    int totalRowsAffected = 0;
    var batches = data.Batch(batchSize);

    foreach (var batch in batches)
    {
        string connstring = "connection string";
        using SnowflakeDbConnection conn = new SnowflakeDbConnection();
        conn.ConnectionString = connstring;
        conn.Open();
        using var transaction = conn.BeginTransaction();
        try
        {
            var dataTable = batch.ToDataTable();
            var sql = GenerateBulkInsertSql(tableName, dataTable);
            var rowsAffected = await conn.ExecuteAsync(sql, dataTable, transaction: transaction);
            transaction.Commit();
            totalRowsAffected += rowsAffected;
        }
        catch
        {
            transaction.Rollback();
            throw;
        }
    }

    return totalRowsAffected;
}



private string GenerateBulkInsertSql(string tableName, DataTable dataTable)
{
    var columns = string.Join(", ", dataTable.Columns.Cast<DataColumn>().Select(c => c.ColumnName));
    var values = string.Join(", ", dataTable.Columns.Cast<DataColumn>().Select(c => ":" + c.ColumnName));
    return $"INSERT INTO {tableName} ({columns}) VALUES ({values})";
}


public static DataTable ToDataTable<T>(this IEnumerable<T> data)
{
    var dataTable = new DataTable();
    var properties = typeof(T).GetProperties();

    foreach (var prop in properties)
    {
        dataTable.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
    }

    foreach (var item in data)
    {
        var row = dataTable.NewRow();
        foreach (var prop in properties)
        {
            row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
        }
        dataTable.Rows.Add(row);
    }

    return dataTable;
}

 


Answers (1)