四、MySql数据批量插入
/// <summary>
/// 为 MySql.Data 组件提供的用于批量操作的方法。
/// </summary>
public sealed class MySqlBatcher : IBatcherProvider
{
/// <summary>
/// 获取或设置提供者服务的上下文。
/// </summary>
public ServiceContext ServiceContext { get; set; }
/// <summary>
/// 将 <see cref="DataTable"/> 的数据批量插入到数据库中。
/// </summary>
/// <param name="dataTable">要批量插入的 <see cref="DataTable"/>。</param>
/// <param name="batchSize">每批次写入的数据量。</param>
public void Insert(DataTable dataTable, int batchSize = 10000)
{
Checker.ArgumentNull(dataTable, "dataTable");
if (dataTable.Rows.Count == 0)
{
return;
}
using (var connection = ServiceContext.Database.CreateConnection())
{
try
{
connection.TryOpen();
using (var command = ServiceContext.Database.Provider.DbProviderFactory.CreateCommand())
{
if (command == null)
{
throw new BatcherException(new ArgumentException("command"));
}
command.Connection = connection;
command.CommandText = GenerateInserSql(ServiceContext.Database, command, dataTable);
if (command.CommandText == string.Empty)
{
return;
}
command.ExecuteNonQuery();
}
}
catch (Exception exp)
{
throw new BatcherException(exp);
}
finally
{
connection.TryClose();
}
}
}
/// <summary>
/// 生成插入数据的sql语句。
/// </summary>
/// <param name="database"></param>
/// <param name="command"></param>
/// <param name="table"></param>
/// <returns></returns>
private string GenerateInserSql(IDatabase database, DbCommand command, DataTable table)
{
var names = new StringBuilder();
var values = new StringBuilder();
var types = new List<DbType>();
var count = table.Columns.Count;
var syntax = database.Provider.GetService<ISyntaxProvider>();
table.EachColumn(c =>
{
if (names.Length > 0)
{
names.Append(",");
}
names.AppendFormat("{0}", DbUtility.FormatByQuote(syntax, c.ColumnName));
types.Add(c.DataType.GetDbType());
});
var i = 0;
foreach (DataRow row in table.Rows)
{
if (i > 0)
{
values.Append(",");
}
values.Append("(");
for (var j = 0; j < count; j++)
{
if (j > 0)
{
values.Append(", ");
}
var isStrType = IsStringType(types[j]);
var parameter = CreateParameter(database.Provider, isStrType, types[j], row[j], syntax.ParameterPrefix, i, j);
if (parameter != null)
{
values.Append(parameter.ParameterName);
command.Parameters.Add(parameter);
}
else if (isStrType)
{
values.AppendFormat("'{0}'", row[j]);
}
else
{
values.Append(row[j]);
}
}
values.Append(")");
i++;
}
return string.Format("INSERT INTO {0}({1}) VALUES {2}", DbUtility.FormatByQuote(syntax, table.TableName), names, values);
}
/// <summary>
/// 判断是否为字符串类别。
/// </summary>
/// <param name="dbType"></param>
/// <returns></returns>
private bool IsStringType(DbType dbType)
{
return dbType == DbType.AnsiString || dbType == DbType.AnsiStringFixedLength || dbType == DbType.String || dbType == DbType.StringFixedLength;
}
/// <summary>
/// 创建参数。
/// </summary>
/// <param name="provider"></param>
/// <param name="isStrType"></param>
/// <param name="dbType"></param>
/// <param name="value"></param>
/// <param name="parPrefix"></param>
/// <param name="row"></param>
/// <param name="col"></param>
/// <returns></returns>
private DbParameter CreateParameter(IProvider provider, bool isStrType, DbType dbType, object value, char parPrefix, int row, int col)
{
//如果生成全部的参数，则速度会很慢，因此，只有数据类型为字符串(包含'号)和日期型时才添加参数
if ((isStrType && value.ToString().IndexOf(''') != -1) || dbType == DbType.DateTime)
{
var name = string.Format("{0}p_{1}_{2}", parPrefix, row, col);
var parameter = provider.DbProviderFactory.CreateParameter();
parameter.ParameterName = name;
parameter.Direction = ParameterDirection.Input;
parameter.DbType = dbType;
parameter.Value = value;
return parameter;
}
return null;
}
}
