/// <summary>
/// 查询并根据结果创建目标类型的实例。
/// SQL命中的记录必须为1行，否则抛出异常。
/// </summary>
/// <typeparam name="T">查询的目标类型。</typeparam>
/// <param name="client"><see cref="IDbClient"/>的实例。</param>
/// <param name="sql">SQL语句。</param>
/// <param name="param">记录SQL参数的对象。</param>
/// <param name="commandType">命令的类型。</param>
/// <param name="timeout">命令的超时时间，单位毫秒。0为不指定。</param>
/// <returns>目标类型的实例。</returns>
/// <exception cref="IncorrectResultSizeException">当SQL命中的记录行数不为 1。</exception>
public static T ForceGet <T>(this IDbClient client,
string sql, object param = null, CommandType commandType = CommandType.Text, int timeout = 0)
{
var paramType = param?.GetType();
var id = new CommandIdentity(client.ConnectionString, sql, commandType, paramType, typeof(T));
var cache = CommandCache.Get(id);
if (cache != null)
{
return(client.ForceGet((IMapper <T>)cache.Mapper, cache.Sql,
cache.Params(client, param), commandType, timeout));
}
cache = CreateCacheItem(sql, commandType, param);
var dbParam = cache.Params(client, param);
var rows = client.Rows(sql, dbParam, commandType, timeout);
IDataRecord row;
int rowCount;
if (!DbClientHelper.TryReadUniqueRow(rows, out row, out rowCount))
{
throw new IncorrectResultSizeException(sql, CommandType.Text, dbParam, 1, rowCount);
}
var mapper = MapperParser.Parse <T>(row);
cache.Mapper = mapper;
CommandCache.Set(id, cache);
var res = mapper.MapRow(row, 1);
return(res);
}
/// <summary>
/// 查询并根据结果创建目标类型的实例。
/// SQL命中的记录必须为1行，否则抛出异常。
/// 这是一个异步操作。
/// </summary>
/// <typeparam name="T">查询的目标类型。</typeparam>
/// <param name="client"><see cref="IDbClient"/>的实例。</param>
/// <param name="sql">SQL语句。</param>
/// <param name="param">参数表。</param>
/// <returns>目标类型的实例。</returns>
/// <exception cref="IncorrectResultSizeException">当SQL命中的记录行数不为 1。</exception>
public static async Task <T> IxForceGetAsync <T>(this IDbClient client, string sql, params object[] param)
{
var identity = new CommandIdentity(client.ConnectionString, sql, null, null, typeof(T));
var cache = CommandCache.Get(identity);
if (cache != null)
{
return(await IxForceGetAsync(client, (IMapper <T>) cache.Mapper, sql, param));
}
var dbParam = GenerateParameters(client, param).ToList();
var rows = await client.RowsAsync(sql, dbParam);
IDataRecord row;
int rowCount;
if (!DbClientHelper.TryReadUniqueRow(rows, out row, out rowCount))
{
throw new IncorrectResultSizeException(sql, CommandType.Text, dbParam, 1, rowCount);
}
var mapper = MapperParser.Parse <T>(row);
CommandCache.Set(identity, new CommandCacheItem {
Mapper = mapper
});
var res = mapper.MapRow(row, 1);
return(res);
}
