0

这就是我编写一个 select 语句来检查数据库中是否有值的方式。

bool userIsPresent=false;
string sqlQuery = string.Format("SELECT * FROM Person WHERE Name = '{0}'", name);

SqlCommand s = new SqlCommand(sqlQuery, con);
con.Open();

SqlDataReader sqlread = s.ExecuteReader();
userIsPresent = sqlread.HasRows;
con.Close();

但现在我需要将一些值保存到数据库中。我怎样才能做到这一点 ？我认为我不应该使用SqlDataReader，那么如何保存并确认数据是否保存到数据库中？

public static bool saveToDb(string name1,string nam2, DateTime dat)
{
    bool ok=false;
    string sqlQuery = string.Format("INSERT into NumbersTable values ('{0}', '{1}','{2}')",name1,nam2,dat );

    SqlCommand s = new SqlCommand(sqlQuery, con);

    con.Open();
    SqlDataReader sr = s.ExecuteReader(); // MIGHT BE WRONG
    ok = sr.HasRows;

    con.Close();
    return ok;
}
4

5 回答 5

6

您需要ExecuteNonQuery在数据库中插入记录。

s.ExecuteNonQuery();

（使用参数化查询来防止 SQL 注入）

于 2013-02-18T08:02:43.073 回答
1

好的，所以您要做的是插入数据库而不是从中读取，因此您必须简单地对数据库执行 sql 查询，而不是读取从中选择的任何数据。为此，您需要使用 ExecuteNonQuery 语句而不是 sqlDataReader。结果看起来像这样

public static bool saveToDb(string name1, string nam2, DateTime dat)
{
  bool ok = false;
  string sqlQuery = "INSERT INTO NumbersTable VALUES (@name1, @nam2, @dat)";
  //This is the sql query we will use and by placing the @ symbol in front of words
  //Will establish them as variables and placeholders for information in an sql command
  //Next we create the sql command
  SqlCommand cmd = new SqlCommand(sqlQuery, con);
  //Here we will insert the correct values into the placeholders via the commands
  //parameters
  cmd.Parameters.AddWithValue("name1", name1);
  //This tells it to replace "@name1" with the value of name1
  cmd.Parameters.AddWithValue("nam2", nam2);
  cmd.Parameters.AddWithValue("dat", dat);
  //Finally we open the connection
  con.Open();
  //Lastly we tell the sql command to execute on the database, in this case inserting
  //the values
  int i = cmd.ExecuteNonQuery();
  //Here we have the results of the execution stored in an integer, this is because
  //ExecuteNonQuery returns the number of rows it has effected, in the case of this
  //Insert statement it would effect one row by creating it, therefore i is 1
  //This is useful for determining if your sql statement was successfully executed
  //As if it returns 0, nothing has happened and something has gone wrong
  con.Close();
}

我希望这对您有所帮助，如果您需要其他任何内容，请随时询问。

于 2013-02-18T10:22:37.790 回答
0

在你的代码中添加这个：

con.open();
S.executeNonQuery();
于 2013-02-18T08:14:53.213 回答
0

试试看...此代码将给出正确的消息..
name1、name2、dat 是数据库中数据表中的列名

public static void saveToDb()
{
string sqlQuery="INSERT into NumbersTable (name1,name2,dat) values ('Princee', 'Singhal','18/02/2012');
SqlCommand s = new SqlCommand(sqlQuery, con) ;
con.Open();
int i=s.ExecuteNonQuery();
if(i>=1)
{
MessageBox.Show("已插入记录");
}
else
{
MessageBox.Show("可能出现问题！") ;
}
con.Close();
}

于 2013-02-18T11:26:54.780 回答
-1

只需要更正现有代码中的某些内容，这绝对会对您有所帮助：

 public static bool executeMyQuery(string sqlQuery)
      {
        try
        {        con.Open();
                 SqlCommand s = new SqlCommand(sqlQuery, con);
                 s.ExecuteNonQuery();
                 con.Close();
                 return true;
         } 
       catch()
        {
          return false;
        }

    And use the above function[executeMyQuery()] anywhere you want to insert like and check whether record is inserted or not like below:

     bool isInserted = false;
     // give dummy value or get it what u want to inser on name1,nam2,dat
     string rawQuery = string.Format("INSERT into NumbersTable values ('{0}', '{1}','{2}')",name1,nam2,dat );

    isInserted = myExecuteQuery(rawQuery);

  if(isInserted)
    { 
      // lblStatus i am taking only to make you understand
      // lblStatus.text = "Record inserted succesfully";
    }
  else
    {
       // lblStatus.text = "Record insertion failed";
    }
于 2013-02-18T08:30:36.177 回答