/// <summary>
/// 解释 FROM 子句。
/// </summary>
/// <param name="DbParameters">用于缓存在解释过程中可能会产生的参数。</param>
/// <returns></returns>
public override string Parsing(ref List <IDbDataParameter> DbParameters)
{
FromBlock fb = (FromBlock)this.Description;
StringBuilder cBuffer = new StringBuilder(" FROM");
foreach (object item in fb.Content)
{
if (item is IDescription)
{
IDescription D = (IDescription)item;
D.DescriptionParserAdapter = fb.DescriptionParserAdapter;
cBuffer.Append(D.GetParser().Parsing(ref DbParameters));
}
else
{
if (cBuffer[cBuffer.Length - 1] == (char)0x20)
{
cBuffer.Append(item);
}
else
{
cBuffer.AppendFormat(" {0}", item);
}
}
}
return(cBuffer.ToString());
}
/// <summary>
/// 创建一个 <see cref="MultiQuerySelector"/> 的对象实例.
/// </summary>
/// <param name="engine">用于执行查询的数据引擎.</param>
internal MultiQuerySelector(DataEngine engine)
{
ReadEngine = engine;
Command = new DbCommandBuilder();
fBlock = new FromBlock();
AgentsIndexes = new Dictionary <Type, AgentBufferItem>();
Agents = new List <AgentBufferItem>();
}