C# 一条sql返回多个表的查询操作
注意:当SQL语句中出现两条Select语句，例如:string sql = "select * from Employees;select * from TblClass";可以用SqlDataReader的NextResult()来接收多个结果集
使用
do
{
}
while(reader.NextResult())
static void Main(string[] args)
{
string constr = "Data Source=zxtiger;Initial Catalog=itcastcn;Integrated Security=True";
using (SqlConnection con = new SqlConnection(constr))
{
string sql = "select * from Employees;select * from TblClass";
using (SqlCommand cmd = new SqlCommand(sql, con))
{
con.Open();
using (SqlDataReader reader = cmd.ExecuteReader())
{
do
{
if (reader.HasRows)
{
while (reader.Read())
{
//循环列
for (int i = 0; i < reader.FieldCount; i++)
{
//根据索引，获取列名
//reader.GetName(i);
//获取当前列的数据类型
string dbType = reader.GetDataTypeName(i);
switch (dbType)
{
case "varchar":
case "nvarchar":
case "char":
case "nchar":
Console.Write(reader.GetString(i) + "\t");
break;
case "int":
Console.Write(reader.GetInt32(i) + "\t");
break;
}
}
Console.WriteLine();
}
}
} while (reader.NextResult()); //当多个结果集的时候可以调用NextResult
}
}
}
Console.WriteLine("ok");
Console.ReadKey();
}
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