Question

我正在使用C＃构建分层树形图，我使用sql查询来获取结果。但是，我似乎无法让这一个查询工作。它给了我在sql-server中我需要的东西，但它在C＃中不起作用。此查询是否有可能的解决方法？ HTML

<div class="Demo">
    <h1>Tree Demo</h1>
    <div class="tree well">
        <ul>
            <li><span>ServerName</span>
            <ul>
                <asp:Repeater ID="rpDatabasesParent" runat="server" OnItemDataBound="loadTables">
                    <ItemTemplate>
                        <li><span><%# Eval("Name") %></span>
                            <ul>
                                <h3>Tables</h3>
                                <asp:Repeater ID="rpTablesChild" runat="server" OnItemDataBound="loadTables">
                                    <ItemTemplate>
                                        <li><span><%# Eval("Tables") %></span></li>
                                    </ItemTemplate>
                                </asp:Repeater>
                            </ul>
                        </li>
                    </ItemTemplate>
                </asp:Repeater>
            </ul>
            </li>
        </ul>
    </div>
</div>

有问题的查询是我的代码中的第二个查询。它是动态的，它给了我我需要的东西，但我无法让它工作。我需要一个解决方法，如果有的话，可以使这个查询正常工作

C＃

protected void Page_Load(object sender, EventArgs e)
{
    testConnection();
}

public void testConnection()
{
    using (SqlConnection connection = new SqlConnection(masterConnectionString))
    {
        try
        {
            connection.Open();
            SqlCommand cmd = new SqlCommand("SELECT Name From Sys.Databases", connection);
            cmd.CommandType = CommandType.Text;
            SqlDataReader rdr = cmd.ExecuteReader();
            rpDatabasesParent.DataSource = rdr;
            rpDatabasesParent.DataBind();
        }
        catch (Exception err)
        {
            //log something
        }
        finally
        {
            connection.Close();
        }
    }

}

protected void loadTables(object sender, RepeaterItemEventArgs e)
{
    RepeaterItem item = e.Item;
    Repeater rpTablesChild = (Repeater)item.FindControl("rpTablesChild");

    using (SqlConnection connection = new SqlConnection(masterConnectionString))
    {
        try
        {
            connection.Open();
            SqlCommand cmd = new SqlCommand("DECLARE @SERVERNAME SYSNAME = @@SERVERNAME, @DB SYSNAME, @Object SYSNAME, @Str NVARCHAR(4000); DECLARE DBList CURSOR LOCAL FAST_FORWARD FOR SELECT name FROM sys.databases; OPEN DBList; FETCH NEXT FROM DBList INTO @DB; WHILE @@FETCH_STATUS = 0 BEGIN SELECT @Str = 'SELECT name AS Tables FROM '+@DB+'.sys.tables; SELECT TABLE_NAME AS Views FROM '+@DB+'.INFORMATION_SCHEMA.VIEWS; SELECT ROUTINE_NAME AS StoredProcedures FROM '+@DB+'.INFORMATION_SCHEMA.ROUTINES;' EXEC sp_executesql @Str FETCH NEXT FROM DBList INTO @DB; END CLOSE DBList; DEALLOCATE DBList;", connection);
            cmd.CommandType = CommandType.Text;
            SqlDataReader rdr = cmd.ExecuteReader();
            rpTablesChild.DataSource = rdr;
            rpTablesChild.DataBind();
        }
        catch (Exception err)
        {
            //log something
        }
        finally
        {
            connection.Close();
        }
    }
}

Answer 1

除此之外，我鼓励您考虑将这段代码转换为存储过程，看起来在很少的地方缺少空格字符。

f.ex：

@StrFETCH

应该是

@Str FETCH

所以整个固定字符串将是：

DECLARE @SERVERNAME SYSNAME= @@SERVERNAME, @DB SYSNAME, @Object SYSNAME, @Str NVARCHAR(4000); DECLARE DBList CURSOR LOCAL FAST_FORWARD FOR SELECT name FROM sys.databases; OPEN DBList; FETCH NEXT FROM DBList INTO @DB; WHILE @@FETCH_STATUS = 0 BEGIN SELECT @Str = 'SELECT name AS Tables FROM '+@DB+'.sys.tables; SELECT TABLE_NAME AS Views FROM '+@DB+'.INFORMATION_SCHEMA.VIEWS; SELECT ROUTINE_NAME AS StoredProcedures FROM '+@DB+'.INFORMATION_SCHEMA.ROUTINES;' EXEC sp_executesql @Str FETCH NEXT FROM DBList INTO @DB; END CLOSE DBList; DEALLOCATE DBList;

此外，您需要考虑此查询将返回多个结果集，因此我不确定使用DataRead是否可以帮助您获得结果。

您可以将所有行合并为1个结果：

CREATE PROCEDURE dbo.GetDbsObjects AS
BEGIN
    CREATE TABLE #output (
      [Db] SYSNAME,
      [Type] VARCHAR(20),
      [Name] SYSNAME
    )

    DECLARE @SERVERNAME SYSNAME= @@SERVERNAME, @DB SYSNAME, @Object SYSNAME, @Str NVARCHAR(4000);
    DECLARE DBList CURSOR LOCAL FAST_FORWARD
    FOR SELECT name
        FROM sys.databases;
    OPEN DBList;
    FETCH NEXT FROM DBList INTO @DB;
    WHILE @@FETCH_STATUS = 0
        BEGIN
            SELECT @Str = 'INSERT INTO #output([Db], [Type], [Name]) SELECT '''+@DB+''', ''table'', name FROM '+@DB+'.sys.tables;'
            EXEC sp_executesql @Str

            SELECT @Str = 'INSERT INTO #output([Db], [Type], [Name]) SELECT '''+@DB+''', ''view'', TABLE_NAME FROM '+@DB+'.INFORMATION_SCHEMA.VIEWS;'
            EXEC sp_executesql @Str

             SELECT @Str = 'INSERT INTO #output([Db], [Type], [Name]) SELECT '''+@DB+''', ''stored procedure'', ROUTINE_NAME FROM '+@DB+'.INFORMATION_SCHEMA.ROUTINES;'
            EXEC sp_executesql @Str

            FETCH NEXT FROM DBList INTO @DB;
        END
    CLOSE DBList;
    DEALLOCATE DBList;

    SELECT * FROM #output

    DROP TABLE #output
END

然后你应该能够从c＃

运行它

    ...
    connection.Open();
    SqlCommand cmd = new SqlCommand("dbo.GetDbsObjects", connection);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlDataReader rdr = cmd.ExecuteReader();
    rpTablesChild.DataSource = rdr;
    ...

Answer 2

首先，我相信您的查询中存在一些错误，您的BEGINSELECT应该是BEGIN SELECT，并且在WHILE的BEGIN之后不会以END结束。

如果这不能解决您的问题，也许您可以尝试这种解决方法：

使用输入参数在SQL Server管理中创建存储过程。然后，您可以使用参数在C＃代码中执行该过程。

以下是一个例子：

  public DataSet RelaEspec(DateTime dtInicio, DateTime dtFim, string CodNo)
    {
        string sql = string.Empty;

        try
        {
            sql = "exec store_procedure @dtInicio, @dtFim, @CodNo ";

            SqlParameterCollection pCol = new SqlParameterCollection();

            pCol.Add("@dtInicio", SqlDbType.DateTime, dtInicio);
            pCol.Add("@dtFim", SqlDbType.DateTime, dtFim);
            pCol.Add("@CodNo", SqlDbType.VarChar, -1, CodNo);

            return ExecuteDataSet(sql, pCol, SessionID, connectionTimeout);
        }
        catch (Exception ex)
        {
            logErro(ex, "DataSet RelatorioEspecializacao");
            return null;
        }
    }

创建存储过程：

USE [YOUR DATABASE]
GO


SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE PROCEDURE [dbo].[store_procedure]
        @SERVERNAME SYSNAME = @@SERVERNAME
      , @DB SYSNAME
      , @Object SYSNAME
      , @Str NVARCHAR(4000);
AS
BEGIN

DECLARE 
DBList CURSOR LOCAL FAST_FORWARDFOR 
SELECT name FROM sys.databases; 
OPEN DBList; 
 FETCH NEXT FROM DBList INTO @DB;
 WHILE @@FETCH_STATUS = 0 
 BEGIN 
   SELECT @Str = 'SELECT name AS Tables FROM '+@DB+'.sys.tables; SELECT 
TABLE_NAME AS Views FROM '+@DB+'.INFORMATION_SCHEMA.VIEWS; SELECT 
ROUTINE_NAME AS StoredProcedures FROM '+@DB+'.INFORMATION_SCHEMA.ROUTINES;' 
    EXEC sp_executesql @StrFETCH NEXT FROM DBList INTO @DB; ENDCLOSE DBList; 
 END
    DEALLOCATE DBList

return 

END
GO

如何为特定的SQL查询执行C＃解决方法

2 个答案: