SqlDataAdapter给我的结果为0

Question

SqlCommand cmd = new SqlCommand(); 
cmd.Connection = con; 
cmd.CommandType = CommandType.Text; 
cmd = CreateParameterizedQuery(); 
SqlDataAdapter dap = new SqlDataAdapter(); 
dap.SelectCommand = cmd; 
DataTable tbl = new DataTable(); 
dap.Fill(tbl); 
if (tbl.Rows.Count > 0) 
{ 
    grid.DataSource = tbl; 
} 

实际的SQL查询将在SQL Management Studio中产生结果。但是我得到0行数据。我在tbl.Rows.Count处设置了一个断点，我发现它是0，并且步进将跳过必要的代码来设置数据源。

private SqlCommand CreateParameterizedQuery() 
    { 
     SqlCommand command = new SqlCommand(); 
     string[] allTheseWords; 
     if (textBoxAllTheseWords.Text.Length > 0) 
     { 
      allTheseWords = textBoxAllTheseWords.Text.Split(' '); 
      string SQLQuery = "SELECT distinct [databaseName].[dbo].[customerTable].[name], [databaseName].[dbo].[customerTable].[dos], [databaseName].[dbo].[customerTable].[ACC], [databaseName].[dbo].[reportTable].[id], [databaseName].[dbo].[reportTable].[ACC], [databaseName].[dbo].[reportTable].[fullreport] FROM [databaseName].[dbo].[reportTable], [databaseName].[dbo].[customerTable] WHERE "; 
      int i = 0; 
      foreach (string word in allTheseWords) 
      { 
       var name = "@word" + (i++).ToString(); 
       command.Parameters.AddWithValue(name, "'%" + word + "%'"); 
       SQLQuery = SQLQuery + String.Format(" [databaseName].[dbo].[reportTable].[fullreport] LIKE {0} AND ", name); 
      } 
      SQLQuery = SQLQuery + " [databaseName].[dbo].[customerTable].[ACC] = [databaseName].[dbo].[reportTable].[ACC]"; 
      command.CommandText = SQLQuery; 
     } 
     return command; 
    } 

我使用与C＃的WinForm在Windows 8

---

的的SQLQuery变量调试

时

SELECT distinct [databaseName].[dbo].[customerTable].[name], [databaseName].[dbo].[customerTable].[dos], [databaseName].[dbo].[customerTable].[ACC], [databaseName].[dbo].[reportTable].[customerID], [databaseName].[dbo].[reportTable].[ACC], [databaseName].[dbo].[reportTable].[fullreport] FROM [databaseName].[dbo].[reportTable], [databaseName].[dbo].[customerTable] WHERE [databaseName].[dbo].[reportTable].[fullreport] LIKE @word0 AND [databaseName].[dbo].[customerTable].[ACC] = [databaseName].[dbo].[reportTable].[ACC] 

debugMySQL是吐出来的是SQL查询使用的方法包含此数据取代参数

public void debugMySQL() 
    { 
     string query = command.CommandText; 
     foreach (SqlParameter p in command.Parameters) 
     { 
      query = query.Replace(p.ParameterName, p.Value.ToString()); 
     } 
     textBox1.Text = query; 
    } 

输出类似于

SELECT distinct [databaseName].[dbo].[customerTable].[name], [databaseName].[dbo].[customerTable].[dos], [databaseName].[dbo].[customerTable].[ACC], [databaseName].[dbo].[reportTable].[id], [databaseName].[dbo].[reportTable].[ACC], [databaseName].[dbo].[reportTable].[fullreport] FROM [databaseName].[dbo].[reportTable], [databaseName].[dbo].[customerTable] WHERE [databaseName].[dbo].[reportTable].[fullreport] LIKE '%single%' AND [databaseName].[dbo].[customerTable].[ACC] = [databaseName].[dbo].[reportTable].[ACC] 

Answer 1

你可以看到使用SQL Profiler它的参数值，参数化查询。