/// <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()));
}
/// <summary>
/// Extendable method: 对视图查询数据源按某属性升序排序
/// </summary>
/// <typeparam name="TModel">视图对象类型</typeparam>
/// <typeparam name="TKey">对象属性类型</typeparam>
/// <param name="source">视图查询数据源</param>
/// <param name="keySelector">指定对象某属性的表达式(根据此属性排序)</param>
/// <returns>排好序的视图查询数据源</returns>
public static IDbView <TModel> OrderBy <TModel, TKey>(this IDbView <TModel> source, Expression <Func <TModel, TKey> > keySelector)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(keySelector, nameof(keySelector));
//创建新的视图查询数据源并返回
return(source.Factory.CreateSortedView(source, keySelector));
}
/// <summary>
/// Extendable method: 筛选并获取筛选后的视图查询数据源
/// </summary>
/// <typeparam name="TModel">视图对象类型</typeparam>
/// <param name="source">视图查询数据源</param>
/// <param name="predicates">筛选表达式数组</param>
/// <returns>被筛选后的数据源</returns>
public static IDbView <TModel> Filter <TModel>(this IDbView <TModel> source, Expression <Func <TModel, bool> >[] predicates)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(predicates, nameof(predicates));
//创建新的视图查询数据源
return(source.Factory.CreateView(source, predicates));
}
/// <summary>
/// Extendable method: 执行非空或可空查询获取视图查询数据源
/// </summary>
/// <typeparam name="TModel">视图对象类型</typeparam>
/// <typeparam name="TProperty">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="isNull">IS NULL 或 IS NOT NULL</param>
/// <returns>视图查询数据源</returns>
public static IDbView <TModel> Null <TModel, TProperty>(this IDbView <TModel> source, Expression <Func <TModel, TProperty> > selector, bool isNull = true)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(selector, nameof(selector));
//拼接sql
string sqlTemplate = isNull ? "IS NULL" : "IS NOT NULL";
//创建新的视图查询数据源
return(source.Factory.CreateView(source, selector.Body.GetMemberExpression(), sqlTemplate));
}
/// <summary>
/// Extendable method: 执行模糊查询获取视图查询数据源
/// </summary>
/// <typeparam name="TModel">视图对象类型</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="value">参数值</param>
/// <param name="isLike">LIKE 或 NOT LIKE</param>
/// <returns>模糊筛选后的视图查询数据源</returns>
public static IDbView <TModel> Like <TModel>(this IDbView <TModel> source, Expression <Func <TModel, string> > selector, string value, bool isLike = true)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(selector, nameof(selector));
Check.ArgumentNull(value, nameof(value));
//获取sql条件表达式
MemberExpression memberExpression = selector.Body.GetMemberExpression();
string sqlTemplate = string.Format("{0} ${1}", isLike ? "LIKE" : "NOT LIKE", memberExpression.Member.Name);
//获取参数
IDbDataParameter parameter = source.ParameterFactory.Parameter(memberExpression.Member.Name, value);
//创建新的视图查询数据源
return(source.Factory.CreateView(source, memberExpression, sqlTemplate, parameter));
}
/// <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="selectorSource">子查询数据源</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, IDbSelectedQuery <TProperty> selectorSource, bool isIn = true)
where TModel : class, new()
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(selector, nameof(selector));
Check.ArgumentNull(selectorSource, nameof(selectorSource));
//获取sql表达式模板
MemberExpression memberExpression = selector.Body.GetMemberExpression();
StringBuilder sqlTemplate = new StringBuilder();
sqlTemplate.AppendLine(isIn ? "IN " : "NOT IN ");
sqlTemplate.Append("\t(");
sqlTemplate.Append(selectorSource.ToWhereSqlString().Trim());
sqlTemplate.Append(")");
sqlTemplate.Replace("\n ", "\n ");
//过滤获取新数据源
return(source.Factory.CreateView(source, memberExpression, sqlTemplate.ToString(), selectorSource.Parameters.ToArray()));
}
/// <summary>
/// Extendable method: 执行区间查询获取视图查询数据源
/// </summary>
/// <typeparam name="TModel">视图对象类型</typeparam>
/// <typeparam name="TProperty">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="left">最小值</param>
/// <param name="right">最大值</param>
/// <returns>视图查询数据源</returns>
public static IDbView <TModel> Between <TModel, TProperty>(this IDbView <TModel> source, Expression <Func <TModel, TProperty> > selector, TProperty left, TProperty right)
where TModel : class, new()
where TProperty : struct
{
//非空验证
Check.ArgumentNull(source, nameof(source));
Check.ArgumentNull(selector, nameof(selector));
Check.ArgumentNull(left, nameof(left));
Check.ArgumentNull(right, nameof(right));
//获取sql表达式模板
MemberExpression memberExpression = selector.Body.GetMemberExpression();
string sqlTemplate = string.Format("BETWEEN ${0}Left AND ${0}Right", memberExpression.Member.Name);
//获取sql参数
IDbDataParameter[] parameters = new IDbDataParameter[]
{
source.ParameterFactory.Parameter(string.Concat(memberExpression.Member.Name, "Left"), left),
source.ParameterFactory.Parameter(string.Concat(memberExpression.Member.Name, "Right"), right)
};
//创建新的视图查询数据源
return(source.Factory.CreateView(source, memberExpression, sqlTemplate, parameters));
}
