1、打开链接
SqlConnection conn = new SqlConnection(SQL);
conn.Open();
2、查询语句
SqlCommand cmd1 = conn.CreateCommand();
cmd1.CommandText = "select * from basicMaterial where materialId = '" + id + "'";
3、验证数据是否存在
SqlDataReader dataReader= cmd1.ExecuteReader();
if (dataReader.HasRows)
{
MessageBox.Show("已存在该记录，保存失败！");
}
4、不存在执行添加操作
else
{
dataReader.Close();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "insert into basicMaterial (pinName,materialId,materialName,materialSpecs) VALUES ('" + pinName + "','" + id + "','" + name + "','" + specs + "')";
int a = cmd.ExecuteNonQuery();
if (a > 0)
{
MessageBox.Show("保存成功！");
}
else
{
MessageBox.Show("保存失败！");
}
}
conn.Close();
附完整代码：
conn.Open();
//在添加数据之前，先要验证数据是否存在，防止不小心多次点击添加按钮造成重复添加数据
SqlCommand cmd1 = conn.CreateCommand();
cmd1.CommandText = "select * from basicMaterial where materialId = '" + id + "'";
SqlDataReader dataReader= cmd1.ExecuteReader();
if (dataReader.HasRows)
{
MessageBox.Show("已存在该记录，保存失败！");
}
else
{
dataReader.Close();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "insert into basicMaterial (pinName,materialId,materialName,materialSpecs) VALUES ('" + pinName + "','" + id + "','" + name + "','" + specs + "')";
int a = cmd.ExecuteNonQuery();
if (a > 0)
{
MessageBox.Show("保存成功！");
}
else
{
MessageBox.Show("保存失败！");
}
}
conn.Close();