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如何在mysql和visual basic中设置变量组?_Mysql_.net_Vb.net - Fatal编程技术网

如何在mysql和visual basic中设置变量组?

如何在mysql和visual basic中设置变量组?,mysql,.net,vb.net,Mysql,.net,Vb.net,如何正确设置@dategiven1 set @dategiven1 = ('1','2','3'); set @dategive4 = 2020; set @activity = "Aerial Cable Installation"; SELECT id, billingreference, opac, projectorder, projectlocation, headedby, dategiven FROM project_info WHERE MONTH(dategiven) I

如何正确设置@dategiven1

set @dategiven1 = ('1','2','3');
set @dategive4 = 2020;
set @activity = "Aerial Cable Installation";

SELECT id, billingreference, opac, projectorder, projectlocation, headedby, dategiven 
FROM project_info 
WHERE MONTH(dategiven) IN (@dategiven1) 
  AND YEAR(dategiven) = @dategiven4 
  AND id IN ( SELECT project_id 
              FROM manpower_project 
              WHERE activity = @activity )
如何应用这个visual basic


谢谢你,对我无法解释的问题表示关注:

MySql中的Month方法似乎返回一个整数,因此,你需要用逗号分隔的数字。一个参数只传递一个值,因此这里的参数不合适。您需要构建一个字符串并将其连接到select语句中

私有函数IncluseMonth为整数,年份为整数,活动为字符串为DataTable 'StringBuilder是可变的,因此它可以避免在每次迭代中创建新字符串和丢弃旧字符串 '以左括号开始字符串 Dim BuildIncluse作为新的StringBuilder '循环遍历数组中的每个元素,并将其与逗号一起添加到字符串生成器中 每个月的每百万 buildincluse.Appendm&, 下一个 '将StringBuilder转换为字符串,删除最后一个逗号并添加右括号。 尺寸str=BUILDING INCLUSE.ToString.Trim,c& '检查字符串的外观 Debug.Printstr Dim dt作为新数据表 'Using…End Using块确保即使出现错误,您的连接和命令也被关闭和释放 将cn用作新的MySqlConnectionYour连接字符串, cmd作为新的MySqlCommandSelect id、billingreference、opac、projectorder、projectlocation、headedby、dategiven 从项目信息 其中monthDate在&str中给出& 而yearDateGived=@dategiven4 从人力资源项目中选择项目id中的 其中activity=@activity,cn cmd.Parameters。Add@dategiven4,MySqlDbType.Int32.Value=Year cmd.Parameters。Add@activity,MySqlDbType.String.Value=Activity 中国公开赛 dt.Loadcmd.ExecuteReader 终端使用 返回dt 端函数 用法:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim intArray = {1, 2, 3}
    Dim dt = InClause(intArray, 2020, "Aerial Cable Installation")
    DataGridView1.DataSource = dt
End Sub