SQL LIKE%NOT SEARCHING

Question

我想使用SQL LIKE函数执行简单搜索.不幸的是,由于某种原因,它似乎没有起作用.以下是我的代码.

private void gvbind()
{
    connection.Open();
    string sql = "";

    if (txtSearch.Text.Trim() == "")
    {
        sql = "SELECT a.cname,[bid],b.[bname],b.[baddress],b.[bcity],b.[bstate],b.[bpostcode],b.[bphone],b.[bfax],b.[bemail] FROM [CLIENT] a INNER JOIN [BRANCH] b ON a.clientID=b.clientID ORDER BY a.[clientID]";
    }
    else
    {
        sql = "SELECT a.cname,[bid],b.[bname],b.[baddress],b.[bcity],b.[bstate],b.[bpostcode],b.[bphone],b.[bfax],b.[bemail] FROM [CLIENT] a INNER JOIN [BRANCH] b ON a.clientID=b.clientID WHERE b.[bname] LIKE '%@search%' ORDER BY a.[clientID]";
    }

    SqlCommand cmd = new SqlCommand(sql,connection);
    cmd.Parameters.AddWithValue("@search", txtSearch.Text.Trim());
    cmd.CommandType = CommandType.Text;
    SqlDataAdapter adp = new SqlDataAdapter();
    adp.SelectCommand = cmd;
    DataSet ds = new DataSet();
    adp.Fill(ds);

    connection.Close();

    if (ds.Tables[0].Rows.Count > 0)
    {
        gvBranch.Enabled = true;
        gvBranch.DataSource = ds;
        gvBranch.DataBind();
    }
    else
    {
        ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());
        ds.Tables[0].Rows.Add(ds.Tables[0].NewRow());

        gvBranch.DataSource = ds;
        gvBranch.DataBind();

        int columncount = gvBranch.Rows[0].Cells.Count;
        gvBranch.Rows[0].Cells.Clear();
        gvBranch.Rows[0].Cells.Add(new TableCell());
        gvBranch.Rows[0].Cells[0].ColumnSpan = columncount;
        gvBranch.Rows[0].Cells[0].Text = "No Records Found";
    }
    ds.Dispose();
}

上面的方法是在Page_Load()方法中调用的

if((!Page.IsPostBack))
{
    gvBind();
}

它在按钮搜索上调用click aslo.但是,它返回当我执行搜索时找不到记录.

Answer 1

使用

LIKE '%' + @search + '%'

代替

LIKE '%@search%'

完整查询;

...
else
{
    sql = "SELECT a.cname,[bid],b.[bname],b.[baddress],b.[bcity],b.[bstate],b.[bpostcode],b.[bphone],b.[bfax],b.[bemail] FROM [CLIENT] a INNER JOIN [BRANCH] b ON a.clientID=b.clientID WHERE b.[bname] LIKE '%' + @search + '%' ORDER BY a.[clientID]";
}

实际上,您不需要[]在查询中的每一列使用方括号().如果您的标识符或对象名称是保留关键字,请使用它们.

谢谢.它有效,但对此有何解释？

主要问题在于,您的查询参数在引号内.在引号中,SQL Server会将其识别为字符串文字,并且永远不会将其视为参数.