/// <summary> /// 是否存在数据 /// </summary> /// <param name="lambda">查询表达式</param> /// <returns>是否存在数据</returns> public bool Any(Expression <Func <TEntity, bool> > lambda) { var convert = PredicateConvert.Convert(Fields, lambda); using (SqliteDataBaseScope.CreateScope(this.DataBase)) { return(this.ExistInner(convert.ConditionSql, convert.Parameters)); } }
/// <summary> /// 载入首行 /// </summary> /// <param name="lambda">查询表达式</param> /// <returns>如果有载入首行,否则返回空</returns> public TEntity FirstOrDefault(Expression <Func <TEntity, bool> > lambda) { var convert = PredicateConvert.Convert(Fields, lambda); return(LoadFirst(convert.ConditionSql, convert.Parameters)); }
/// <summary> /// 分析Lambda表达式 /// </summary> /// <typeparam name="T">方法类型</typeparam> /// <param name="columns">关联字段</param> /// <param name="predicate">Lambda表达式</param> /// <returns></returns> public static ConditionItem Convert <T>(string[] columns, Expression <T> predicate) { var convert = new PredicateConvert(columns); return(convert.Convert(predicate)); }