vb.net 将数据库中表1的数据（商品编码，名称，规格，数量,日期等），在选择的日期范围内合并（商品编码，名称，规格）相同的数据，且数量大于1，与有相同商品编码的表2中库存 以及 有相同商品编码的表2中销量 显示在datagridviewx 控件上 ，详细代码

首先，需要连接数据库并查询表1中的数据：

Dim connString As String = "Data Source=YourDatabaseServerName;Initial Catalog=YourDatabaseName;Integrated Security=True"
Dim conn As New SqlConnection(connString)
Dim cmd As New SqlCommand()
cmd.Connection = conn
cmd.CommandType = CommandType.Text
cmd.CommandText = "SELECT 商品编码, 名称, 规格, SUM(数量) AS 数量, CONVERT(date, 日期) AS 日期 FROM 表1 WHERE 日期 BETWEEN @FromDate AND @ToDate GROUP BY 商品编码, 名称, 规格, CONVERT(date, 日期) HAVING SUM(数量) > 1"
cmd.Parameters.AddWithValue("@FromDate", fromDate)
cmd.Parameters.AddWithValue("@ToDate", toDate)
Dim adapter As New SqlDataAdapter(cmd)
Dim table1 As New DataTable()
adapter.Fill(table1)

然后，需要查询表2中与表1中商品编码相同的数据，包括库存和销量：

cmd.CommandText = "SELECT 商品编码, SUM(库存) AS 库存, SUM(销量) AS 销量 FROM 表2 WHERE 商品编码 IN (SELECT DISTINCT 商品编码 FROM 表1 WHERE 日期 BETWEEN @FromDate AND @ToDate AND SUM(数量) > 1) GROUP BY 商品编码"
Dim table2 As New DataTable()
adapter.Fill(table2)

最后，将表1和表2中的数据合并，并绑定到DataGridView控件上：

Dim result = From t1 In table1.AsEnumerable()
             Join t2 In table2.AsEnumerable() On t1.Field(Of String)("商品编码") Equals t2.Field(Of String)("商品编码") Into temp
             From t In temp.DefaultIfEmpty()
             Select New With {
                 .商品编码 = t1.Field(Of String)("商品编码"),
                 .名称 = t1.Field(Of String)("名称"),
                 .规格 = t1.Field(Of String)("规格"),
                 .数量 = t1.Field(Of Integer)("数量"),
                 .日期 = t1.Field(Of Date)("日期"),
                 .库存 = If(t IsNot Nothing, t.Field(Of Integer)("库存"), 0),
                 .销量 = If(t IsNot Nothing, t.Field(Of Integer)("销量"), 0)
             }
DataGridView1.DataSource = result.ToList()

完整的代码如下：

Dim connString As String = "Data Source=YourDatabaseServerName;Initial Catalog=YourDatabaseName;Integrated Security=True"
Dim conn As New SqlConnection(connString)
Dim cmd As New SqlCommand()
cmd.Connection = conn
cmd.CommandType = CommandType.Text
cmd.CommandText = "SELECT 商品编码, 名称, 规格, SUM(数量) AS 数量, CONVERT(date, 日期) AS 日期 FROM 表1 WHERE 日期 BETWEEN @FromDate AND @ToDate GROUP BY 商品编码, 名称, 规格, CONVERT(date, 日期) HAVING SUM(数量) > 1"
cmd.Parameters.AddWithValue("@FromDate", fromDate)
cmd.Parameters.AddWithValue("@ToDate", toDate)
Dim adapter As New SqlDataAdapter(cmd)
Dim table1 As New DataTable()
adapter.Fill(table1)

cmd.CommandText = "SELECT 商品编码, SUM(库存) AS 库存, SUM(销量) AS 销量 FROM 表2 WHERE 商品编码 IN (SELECT DISTINCT 商品编码 FROM 表1 WHERE 日期 BETWEEN @FromDate AND @ToDate AND SUM(数量) > 1) GROUP BY 商品编码"
Dim table2 As New DataTable()
adapter.Fill(table2)

Dim result = From t1 In table1.AsEnumerable()
             Join t2 In table2.AsEnumerable() On t1.Field(Of String)("商品编码") Equals t2.Field(Of String)("商品编码") Into temp
             From t In temp.DefaultIfEmpty()
             Select New With {
                 .商品编码 = t1.Field(Of String)("商品编码"),
                 .名称 = t1.Field(Of String)("名称"),
                 .规格 = t1.Field(Of String)("规格"),
                 .数量 = t1.Field(Of Integer)("数量"),
                 .日期 = t1.Field(Of Date)("日期"),
                 .库存 = If(t IsNot Nothing, t.Field(Of Integer)("库存"), 0),
                 .销量 = If(t IsNot Nothing, t.Field(Of Integer)("销量"), 0)
             }
DataGridView1.DataSource = result.ToList()