Question

如何计算c＃中sql表的行数？我需要从我的数据库中提取一些数据......

Answer 1

您可以尝试这样：

select count(*) from tablename where columname = 'values'

C＃代码将是这样的： -

public int A()
{
   string stmt = "SELECT COUNT(*) FROM dbo.tablename";
   int count = 0;

   using(SqlConnection thisConnection = new SqlConnection("Data Source=DATASOURCE"))
   {
       using(SqlCommand cmdCount = new SqlCommand(stmt, thisConnection))
       {
           thisConnection.Open();
           count = (int)cmdCount.ExecuteScalar();
       }
   }
   return count;
}

Answer 2

您需要先从c＃建立数据库连接。然后，您需要将以下查询作为commandText传递。

Select count(*) from TableName

使用ExecuteScalar / ExecuteReader获取返回的计数。

Answer 3

你的意思是喜欢这个吗？

SELECT COUNT(*) 
FROM yourTable 
WHERE ....

Answer 4

您可以创建一直可以使用的全局功能

    public static int GetTableCount(string tablename, string connStr = null)
    {
        string stmt = string.Format("SELECT COUNT(*) FROM {0}", tablename);
        if (String.IsNullOrEmpty(connStr))
            connStr = ConnectionString;
        int count = 0;
        try
        {

            using (SqlConnection thisConnection = new SqlConnection(connStr))
            {
                using (SqlCommand cmdCount = new SqlCommand(stmt, thisConnection))
                {
                    thisConnection.Open();
                    count = (int)cmdCount.ExecuteScalar();
                }
            }
            return count;
        }
        catch (Exception ex)
        {
            VDBLogger.LogError(ex);
            return 0;
        }
    }

Answer 5

这对我有用

using (var context = new BloggingContext())
{
   var blogs = context.Blogs.SqlQuery("SELECT * FROM dbo.Blogs").ToList();
}

有关更多信息，请参见：https://docs.microsoft.com/es-es/ef/ef6/querying/raw-sql?redirectedfrom=MSDN

Answer 6

使用它的工作

        string strQuery = "SELECT * FROM staff WHERE usertype='lacturer'";

        connect.Open();

        SqlCommand cmd = new SqlCommand(strQuery, connect);
        SqlDataAdapter OleDbDa = new SqlDataAdapter(cmd);
        DataSet dsData = new DataSet();
        OleDbDa.Fill(dsData);

        connect.Close();
        
        std.Text = dsData.Tables[0].Rows.Count.ToString();

如何计算c＃中sql表的行数？

6 个答案: