执行插入命令，返回插入的Id在Sql

Question

我在 MVC 4 中使用 C# 将一些值插入到 SQL 表中。实际上，我想插入值并返回最后插入记录的“ID”。 我使用以下代码。

public class MemberBasicData
{
    public int Id { get; set; }
    public string Mem_NA { get; set; }
    public string Mem_Occ { get; set; }     
}

插入时 ID 在数据库中自动递增。

public int CreateNewMember(string Mem_NA, string Mem_Occ )
{
    using (SqlConnection con=new SqlConnection(Config.ConnectionString))
    {
        using(SqlCommand cmd=new SqlCommand("INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ)",con))
        {
            cmd.Parameters.AddWithValue("@na", Mem_NA);
            cmd.Parameters.AddWithValue("@occ", Mem_Occ);
            con.Open();

            int modified = cmd.ExecuteNonQuery();

            if (con.State == System.Data.ConnectionState.Open) con.Close();
                return modified;
        }
    }
}
   

我知道ExecuteNonQuery表示影响行的数字。 而不是我使用

int modified = (int)cmd.ExecuteScalar();

但它不起作用。 请帮我解决这个问题。 是否有像cmd.ExecuteInsertAndGetID()这样的代码（不适用于我的代码）。

Answer 1

以下解决方案适用于 sql server 2005 及更高版本。 您可以使用输出来获取必填字段。 代替 id，您可以编写要返回的密钥。 像这样做

FOR SQL SERVER 2005 及以上

    using(SqlCommand cmd=new SqlCommand("INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) output INSERTED.ID VALUES(@na,@occ)",con))
    {
        cmd.Parameters.AddWithValue("@na", Mem_NA);
        cmd.Parameters.AddWithValue("@occ", Mem_Occ);
        con.Open();

        int modified =(int)cmd.ExecuteScalar();

        if (con.State == System.Data.ConnectionState.Open) 
            con.Close();

        return modified;
    }
}

对于以前的版本

    using(SqlCommand cmd=new SqlCommand("INSERT INTO Mem_Basic(Mem_Na,Mem_Occ)  VALUES(@na,@occ);SELECT SCOPE_IDENTITY();",con))
    {
        cmd.Parameters.AddWithValue("@na", Mem_NA);
        cmd.Parameters.AddWithValue("@occ", Mem_Occ);
        con.Open();

        int modified = Convert.ToInt32(cmd.ExecuteScalar());

        if (con.State == System.Data.ConnectionState.Open) con.Close();
            return modified;
    }
}

Answer 2

将查询更改为

"INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ); SELECT SCOPE_IDENTITY()"

这将返回最后插入的 ID，然后您可以使用ExecuteScalar

Answer 3

SQL Server 存储过程：

CREATE PROCEDURE [dbo].[INS_MEM_BASIC]
    @na varchar(50),
    @occ varchar(50),
    @New_MEM_BASIC_ID int OUTPUT
AS
BEGIN
    SET NOCOUNT ON;

    INSERT INTO Mem_Basic
    VALUES (@na, @occ)

    SELECT @New_MEM_BASIC_ID = SCOPE_IDENTITY()
END

C#代码：

public int CreateNewMember(string Mem_NA, string Mem_Occ )
{
    // values 0 --> -99 are SQL reserved.
    int new_MEM_BASIC_ID = -1971;   
    SqlConnection SQLconn = new SqlConnection(Config.ConnectionString);
    SqlCommand cmd = new SqlCommand("INS_MEM_BASIC", SQLconn);

    cmd.CommandType = CommandType.StoredProcedure;

    SqlParameter outPutVal = new SqlParameter("@New_MEM_BASIC_ID", SqlDbType.Int);

    outPutVal.Direction = ParameterDirection.Output;
    cmd.Parameters.Add(outPutVal);
    cmd.Parameters.Add("@na", SqlDbType.Int).Value = Mem_NA;
    cmd.Parameters.Add("@occ", SqlDbType.Int).Value = Mem_Occ;

    SQLconn.Open();
    cmd.ExecuteNonQuery();
    SQLconn.Close();

    if (outPutVal.Value != DBNull.Value) new_MEM_BASIC_ID = Convert.ToInt32(outPutVal.Value);
        return new_MEM_BASIC_ID;
}

我希望这些对你有帮助......

如果你愿意，你也可以使用它......

public int CreateNewMember(string Mem_NA, string Mem_Occ )
{
    using (SqlConnection con=new SqlConnection(Config.ConnectionString))
    {
        int newID;
        var cmd = "INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ);SELECT CAST(scope_identity() AS int)";

        using(SqlCommand cmd=new SqlCommand(cmd, con))
        {
            cmd.Parameters.AddWithValue("@na", Mem_NA);
            cmd.Parameters.AddWithValue("@occ", Mem_Occ);

            con.Open();
            newID = (int)insertCommand.ExecuteScalar();

            if (con.State == System.Data.ConnectionState.Open) con.Close();
                return newID;
        }
    }
}

Answer 4

USE AdventureWorks2012;
GO
IF OBJECT_ID(N't6', N'U') IS NOT NULL 
    DROP TABLE t6;
GO
IF OBJECT_ID(N't7', N'U') IS NOT NULL 
    DROP TABLE t7;
GO
CREATE TABLE t6(id int IDENTITY);
CREATE TABLE t7(id int IDENTITY(100,1));
GO
CREATE TRIGGER t6ins ON t6 FOR INSERT 
AS
BEGIN
   INSERT t7 DEFAULT VALUES
END;
GO
--End of trigger definition

SELECT id FROM t6;
--IDs empty.

SELECT id FROM t7;
--ID is empty.

--Do the following in Session 1
INSERT t6 DEFAULT VALUES;
SELECT @@IDENTITY;
/*Returns the value 100. This was inserted by the trigger.*/

SELECT SCOPE_IDENTITY();
/* Returns the value 1. This was inserted by the 
INSERT statement two statements before this query.*/

SELECT IDENT_CURRENT('t7');
/* Returns value inserted into t7, that is in the trigger.*/

SELECT IDENT_CURRENT('t6');
/* Returns value inserted into t6. This was the INSERT statement four statements before this query.*/

-- Do the following in Session 2.
SELECT @@IDENTITY;
/* Returns NULL because there has been no INSERT action 
up to this point in this session.*/

SELECT SCOPE_IDENTITY();
/* Returns NULL because there has been no INSERT action 
up to this point in this scope in this session.*/

SELECT IDENT_CURRENT('t7');
/* Returns the last value inserted into t7.*/

Answer 5

SELECT SCOPE_IDENTITY() AS 'Identity'

这将返回仅在当前范围内插入的标识值

SELECT @@IDENTITY AS 'Identity'; 

这不限于特定范围因此这将返回标识列的最新值，而不一定是来自同一范围的标识值。

Answer 6

如果您使用 EF：

 Class Person{
 public int Id {get;set;}
 public string Name {get;set;}
}

您设置名称值：

 Person p = new Person(){
  Name = "James"
};
DbContext.Persons.Add(p);
DbContext.SaveChanges();

//p.Id = new Id from database
//p.Name = James

您只需保存它，您就会从数据库中获得 Id。

Answer 7

可以在 Insert 查询链接中使用OUTPUT Inserted.Id ：

INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) OUTPUT INSERTED.Id VALUES(@na,@occ);

将响应存储在结果变量中，然后读取 result[0].Id，或者可以使用 ExecuteSingle 并直接读取 result.Id 以访问插入的 id 或任何其他 col 数据。

Answer 8

using(SqlCommand cmd=new SqlCommand("INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) " +
    "VALUES(@na,@occ);SELECT SCOPE_IDENTITY();",con))
{
    cmd.Parameters.AddWithValue("@na", Mem_NA);
    cmd.Parameters.AddWithValue("@occ", Mem_Occ);
    con.Open();

    int modified = cmd.ExecuteNonQuery();

    if (con.State == System.Data.ConnectionState.Open) con.Close();
        return modified;
}

SCOPE_IDENTITY ：返回插入到同一范围内的标识列中的最后一个标识值。 有关更多详细信息，请访问http://technet.microsoft.com/en-us/library/ms190315.aspx