/// <summary>
/// 查询块，通常用于最终执行前 生成where。
/// </summary>
/// <typeparam name="T">任意类型</typeparam>
/// <param name="where">where action</param>
/// <param name="end">end action</param>
/// <returns>返回处理结果。</returns>
public T QueryBlock <T>(UpdateCommandBuilderQueryBlockWhereAction where, UpdateCommandBuilderQueryBlockEndAction <T> end)
{
PreRemoveFields();
using (ISelectCommandBuilder whereBuilder = CreateSelect()) {
System.Collections.Generic.List <object> array = new System.Collections.Generic.List <object>();
System.Collections.Generic.List <string> names = new System.Collections.Generic.List <string>();
whereBuilder.AddCommandParameter = (p) => {
array.Add(p);
string name = "@p_" + (array.Count + _fields.Count);
names.Add(name);
return(name);
};
whereBuilder.Select("1");
if (where != null)
{
if (!where (whereBuilder))
{
return(default(T));
}
}
if (end != null)
{
string commandText = BuilderCommandText();
string whereCommandText = whereBuilder.WhereCommandText;
for (int i = 0; i < names.Count; i++)
{
string name = "@p" + (i + 1 + _fields.Count);
whereCommandText = whereCommandText.Replace(names[i], name);
}
return(end(commandText + whereCommandText, GetValues(array.ToArray())));
}
return(default(T));
}
}
/// <summary>
/// 创建查询命令构造器（自动关联参数）。
/// </summary>
/// <returns>返回构造器对象。</returns>
public virtual ISelectCommandBuilder CreateBuilder()
{
ISelectCommandBuilder builder = _dataContext.CreateSelect("table", CommandText);
builder.AddCommandParameter = AddCommandParameter_ISelectCommandBuilder;
builder.AutoEnd = true;
System.EventHandler endedHandler = null; endedHandler = (p1, p2) => {
builder.Ended -= endedHandler;
CommandText = builder.CommandText;
};
builder.Ended += endedHandler;
return(builder);
}
