如何动态获取与不同组合集相关的数据

Question

我想获取与不同组合集相关的数据。

EX :

如果我有table：EmployeeLocation

empNum  locationId  extensionId  year

 534      CX1         AX         2015
 534      LM1         RQ         2015
 677      LM1         ST         2015

回复：534,2015

现在我想查询所有在位置 (CX1 AND LM1) 的员工，他们都在 2015。也许我将组合更改为 (CX1 AND LM1 AND LR3)...等等

如何使类似的东西成为动态组合。根据用户输入的一组位置组合。

Answer 1

DECLARE
     locationId VARCHAR(3);
     year INTEGER;

BEGIN
  EXECUTE IMMEDIATE    

    'SELECT empNum FROM EmployeeLocation
     WHERE locationId = CX1 AND locationId = LM1 AND year = 2015';
END;

这可能是描述查询的一种简单方法。我认为剩下的就是一个事件处理程序来指定要使用的locationId。

这里更详细：

CREATE OR REPLACE PROCEDURE empNum(locId VARCHAR(3), yr VARCHAR(4)) IS
   TYPE cur_typ IS REF CURSOR;
   c cur_typ;
   locationId VARCHAR(3);
   year INTEGER;
BEGIN
  EXECUTE IMMEDIATE    

    'SELECT empNum FROM EmployeeLocation
     WHERE locationId = locId AND locationId = locId AND year = yr';
END;

我认为使用 cur_type 作为参考游标可以用于查询字符串。

来源：https://docs.oracle.com/cd/A97630_01/appdev.920/a96590/adg09dyn.htm

Answer 2

您可以使用 Linq 的方法如下。

假设你有一个 class 如下：

private class EmployeeLocation {
    public int EmpNum {get; set;} 
    public string LocationId {get; set;}
    public string ExtensionId {get; set;}
    public int Year {get; set;} 
}

您可以创建一个方法来处理基于输入中提供的参数的搜索：

public IEnumerable<EmployeeLocation> Search(
    int[] empNumArray, 
    string[] locationIdArray, 
    string[] extensionIdArray, 
    int[] yearArray){

    IEnumerable<EmployeeLocation> result = EmployeeLocationList;
    if (empNumArray != null){
        foreach(var empNum in empNumArray){
            result = result.Where(r => r.EmpNum == empNum);
        }
    }
    if (locationIdArray != null){
        foreach(var locationId in locationIdArray){
            result = result.Where(r => r.LocationId);
        }
    }
    if (extensionIdArray != null){
        foreach(var extensionId in extensionIdArray){
            result = result.Where(r => r.ExtensionId == extensionId);
        }
    }
    if (yearArray != null){
        foreach(var year in yearArray ){
            result = result.Where(r => r.Year == year);
        }
    }
    return result;
}

Answer 3

检查每个条件然后取结果的交集如何？

    public IEnumerable<int> Search(IEnumerable<Employee> employees, IEnumerable<Condition> conditions) {
        var subresults = new List<IEnumerable<int>>();
        IEnumerable<int> result = null;
        foreach (var condition in conditions) {
            subresults.add(employees.Where(e => e.CheckCondition(condition)).Select(e => e.EmpNum));
        }
        foreach (var subresult in subresults) {
            if (result == null) {
                result = subresult;
            } else {
                result = result.Intersect(subresult)
            }
        }
        return result;
    }

如何动态获取与不同组合集相关的数据

How to get data related to sets of different combinations dynamically

c#

sql

linq

asp.net

informix