如何在將數據插入到SQLite表中後獲取最後一行ID

Question

我正在使用SQLite和SQLite-Net Wrapper for WinRT應用程序。其他平臺可能有SQLite，但實現可能會不同，例如使用SQLite-Net API。

如何在插入SQLite後立即獲取最後一行ID？謝謝

 

using (var db = new SQLite.SQLiteConnection(DBPath)) 
      { 
       var newOrder = new SalesOrder() 
       { 
        CustId = g_intCustId, 
        Customer_No = txtBlkCustomer.Text.Trim(), 
        Order_Date = DateTime.Today      
       }; 

       db.Insert(newOrder); 

     } 

--1--- Update : I am using SQLite-Net Wrapper. I am not using SQLite -WInRT
 

I get the following error : 

The type arguments for method 'SQLite.SQLiteConnection.ExecuteScalar(string, params object[])' 
 
cannot be inferred from the usage. Try specifying the type arguments explicitly.  

db.Insert(newOrder); 
var key = db.ExecuteScalar("SELECT last_insert_rowid()"); 


---2-- Update 
 

This is the class : 

My problem is : How to get the SId immediately after inserting a record using above code. 

class SalesOrder 
    { 
     [PrimaryKey, AutoIncrement] 
     public int SId { get; set; } 

     public int CustId { get; set; } 
     public string Customer_No { get; set; } 
     public DateTime Order_Date { get; set; } 

    } 

Answer 1

在SQLite-net，Insert方法返回插入（SQLite.cs）行的數目。所以如果你想讓它返回最後一行ID，你可以更新它來做到這一點。

當前實施。

public int Insert (object obj, string extra, Type objType) 
{ 
    if (obj == null || objType == null) { 
     return 0; 
    } 


    var map = GetMapping (objType); 

    #if NETFX_CORE 
    if (map.PK != null && map.PK.IsAutoGuid) 
    { 
     // no GetProperty so search our way up the inheritance chain till we find it 
     PropertyInfo prop; 
     while (objType != null) 
     { 
      var info = objType.GetTypeInfo(); 
      prop = info.GetDeclaredProperty(map.PK.PropertyName); 
      if (prop != null) 
      { 
       if (prop.GetValue(obj, null).Equals(Guid.Empty)) 
       { 
        prop.SetValue(obj, Guid.NewGuid(), null); 
       } 
       break; 
      } 

      objType = info.BaseType; 
     } 
    } 
    #else 
    if (map.PK != null && map.PK.IsAutoGuid) { 
     var prop = objType.GetProperty(map.PK.PropertyName); 
     if (prop != null) { 
      if (prop.GetValue(obj, null).Equals(Guid.Empty)) { 
       prop.SetValue(obj, Guid.NewGuid(), null); 
      } 
     } 
    } 
    #endif 


    var replacing = string.Compare (extra, "OR REPLACE", StringComparison.OrdinalIgnoreCase) == 0; 

    var cols = replacing ? map.InsertOrReplaceColumns : map.InsertColumns; 
    var vals = new object[cols.Length]; 
    for (var i = 0; i < vals.Length; i++) { 
     vals [i] = cols [i].GetValue (obj); 
    } 

    var insertCmd = map.GetInsertCommand (this, extra); 
    var count = insertCmd.ExecuteNonQuery (vals); 

    if (map.HasAutoIncPK) 
    { 
     var id = SQLite3.LastInsertRowid (Handle); 
     map.SetAutoIncPK (obj, id); 
    } 

    return count; 
} 

更新的實現。

public int Insert (object obj, string extra, Type objType) 
{ 
    if (obj == null || objType == null) { 
     return 0; 
    } 


    var map = GetMapping (objType); 

    #if NETFX_CORE 
    if (map.PK != null && map.PK.IsAutoGuid) 
    { 
     // no GetProperty so search our way up the inheritance chain till we find it 
     PropertyInfo prop; 
     while (objType != null) 
     { 
      var info = objType.GetTypeInfo(); 
      prop = info.GetDeclaredProperty(map.PK.PropertyName); 
      if (prop != null) 
      { 
       if (prop.GetValue(obj, null).Equals(Guid.Empty)) 
       { 
        prop.SetValue(obj, Guid.NewGuid(), null); 
       } 
       break; 
      } 

      objType = info.BaseType; 
     } 
    } 
    #else 
    if (map.PK != null && map.PK.IsAutoGuid) { 
     var prop = objType.GetProperty(map.PK.PropertyName); 
     if (prop != null) { 
      if (prop.GetValue(obj, null).Equals(Guid.Empty)) { 
       prop.SetValue(obj, Guid.NewGuid(), null); 
      } 
     } 
    } 
    #endif 


    var replacing = string.Compare (extra, "OR REPLACE", StringComparison.OrdinalIgnoreCase) == 0; 

    var cols = replacing ? map.InsertOrReplaceColumns : map.InsertColumns; 
    var vals = new object[cols.Length]; 
    for (var i = 0; i < vals.Length; i++) { 
     vals [i] = cols [i].GetValue (obj); 
    } 

    var insertCmd = map.GetInsertCommand (this, extra); 
    var count = insertCmd.ExecuteNonQuery (vals); 
    long id = 0; //New line 
    if (map.HasAutoIncPK) 
    { 
     id = SQLite3.LastInsertRowid (Handle); //Updated line 
     map.SetAutoIncPK (obj, id); 
    } 

    //Updated lines 
    //return count; //count is row affected, id is primary key 
    return (int)id; 
    //Updated lines 
} 

Answer 2

你對連接有ExecuteScalar方法嗎？然後使用

var key = db.ExecuteScalar<int>("SELECT last_insert_rowid()");