/// <summary>
/// Extendable method: 过滤数据源中属性包含(或不包含)某些值的实体(生成Sql IN表达式)
/// </summary>
/// <typeparam name="TModel">视图对象类型</typeparam>
/// <typeparam name="TProperty">对象属性类型</typeparam>
/// <param name="source">视图查询数据源</param>
/// <param name="selector">指定对象某属性的表达式</param>
/// <param name="values">对象属性所包含的值</param>
/// <param name="isIn">IN 或 NOT IN</param>
/// <returns>新的视图查询数据源</returns>
public static IDbView <TModel> In <TModel, TProperty>(this IDbView <TModel> source, Expression <Func <TModel, TProperty> > selector, TProperty[] values, bool isIn = true)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(selector, nameof(selector));
Check.ArgumentNull(values, nameof(values));
//获取sql表达式模板
MemberExpression memberExpression = selector.Body.GetMemberExpression();
StringBuilder sqlTemplate = new StringBuilder();
sqlTemplate.AppendLine(isIn ? "IN " : "NOT IN ");
for (int i = 0; i < values.Length; i++)
{
sqlTemplate.AppendFormat("\t {0}", i == 0 ? '(' : ' ');
sqlTemplate.AppendFormat("${0}", memberExpression.Member.Name);
sqlTemplate.AppendFormat("{0}{1}", i, (i + 1 == values.Length) ? ")" : ",\n");
}
//获取原始参数集合
IDbDataParameter[] parameters = new IDbDataParameter[values.Length];
for (int i = 0; i < values.Length; i++)
{
parameters[i] = source.ParameterFactory.Parameter(string.Concat(memberExpression.Member.Name, i), values[i]);
}
//过滤获取新数据源
return(source.Factory.CreateView(source, memberExpression, sqlTemplate.ToString(), parameters.ToArray()));
}
