求助：查询两个SQL数据库的两个不同表的数据到dataGridView里

现有同一类数据分别存在两个不同的数据库的不同表里。数据内容一样，但两个表的字段名不同。
在textBox1里输入要模糊查询的内容，从两个库/两个表里查出来给dataGridView1。

数据库1：AA 数据库：GM
表1：xsact 表2：stockin


下面是我的代码，不能两个表同时查询出来给dataGridView1。请各位大侠帮忙看下怎么弄。
DataTable dt = new DataTable();
DataTable dt1 = new DataTable();
string connsql = "server=192.168.123.3;database=aa;user=sa;pwd=sa";
SqlConnection conn = new SqlConnection();
conn.ConnectionString = connsql;
conn.Open();

//用SQL语句查询XSCAT表里的所需数据，并将数据值赋于myda变量，将myda变量的数据赋于dt变量，将dt变量的数据赋于datadataGridView1
string sql = "select s.fapiaohao,s.idate,s.porder,s.code,h.name,cast(s.jitu0 as int) as jitu0,s.aprice,s.kounyuugaku from xsact s,xhead h where s.code=h.code and s.fapiaohao like '%" + textBox1.Text + "%'";
SqlDataAdapter myda = new SqlDataAdapter(sql, conn);
myda.Fill(dt);
dataGridView1.DataSource = dt;
this.dataGridView1.AllowUserToAddRows = false; //不显示dataGridView1的最后一行(空行)
dt.DefaultView.Sort = "idate"; //以发票号从小到大排序

//声明一个sum变量，用于汇总dataGridView1里查询到的jitu0数量并赋给textBox3
double sum = 0;
for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
sum += Convert.ToDouble(dataGridView1.Rows[i].Cells[5].Value);
}
textBox2.Text = sum.ToString(); //将sum变量汇总到的dataGridView1数据赋值给textBox2

double sum1 = 0;
for (int j = 0; j < dataGridView1.Rows.Count; j++)
{
sum1 += Convert.ToDouble(dataGridView1.Rows[j].Cells[7].Value);
}
textBox3.Text = sum1.ToString();
conn.Close();

//查询stockin表的数据
string connsql1 = "server=192.168.123.3;database=gm;user=sa;pwd=sa";
SqlConnection conn1 = new SqlConnection();
conn1.ConnectionString = connsql1;
conn1.Open();
string sql1 = "select invno as fapiaohao,crtdate as idate,porder,itemcode as code,itemname as name,cast(qty as int) as jitu0,price as aprice from stockin where invno like '%" + textBox1.Text + "%'";
SqlDataAdapter myda1 = new SqlDataAdapter(sql1, conn1);
myda1.Fill(dt1);
dataGridView1.DataSource = dt1;
this.dataGridView1.AllowUserToAddRows = false; //不显示dataGridView1的最后一行(空行)
dt1.DefaultView.Sort = "idate"; //以发票号从小到大排序
conn1.Close();