private List <TSDB_FIELD> FetchFields(long taos)
{
const int fieldSize = 68;
List <TSDB_FIELD> fields = new List <TSDB_FIELD>();
long result = taos_use_result(taos);
if (result == 0)
{
return(fields);
}
int fieldCount = taos_field_count(taos);
IntPtr fieldsPtr = taos_fetch_fields(result);
for (int i = 0; i < fieldCount; ++i)
{
int offset = i * fieldSize;
TSDB_FIELD meta = new TSDB_FIELD();
meta.name = Marshal.PtrToStringAnsi(fieldsPtr + offset);
meta.bytes = Marshal.ReadInt16(fieldsPtr + offset + 64);
meta.type = Marshal.ReadByte(fieldsPtr + offset + 66);
fields.Add(meta);
}
return(fields);
}
/// <summary>
/// SQl查询返回System.Data.DataTable
/// </summary>
/// <param name="sql">SQl查询语句</param>
/// <returns></returns>
public DataTable QueryToDataTable(string sql)
{
DataTable dt = new DataTable();
if (_taosConn == 0)
{
return(new DataTable());
}
try
{
if (SQLCommand(sql) == TSDB_CODE.SUCCESS)
{
int fieldCount = TDengine.taos_field_count(_taosConn);
Console.WriteLine("field count: " + fieldCount);
List <TSDB_FIELD> fields = FetchFields(_taosConn);
foreach (var f in fields)
{
dt.Columns.Add(f.name, f.CSharpTypeName());
#if (DEBUG)
Console.WriteLine(string.Format("name:{0} type:{1} name:{2} bytes:{3}", f.name.PadRight(20), f.type.ToString().PadRight(5), f.TSDBDataTypeName().PadRight(10), f.bytes.ToString().PadRight(5)));
#endif
}
long result = taos_use_result(_taosConn);
if (result == 0)
{
Console.WriteLine(sql + " result set is null");
return(dt);
}
IntPtr rowdata;
long queryRows = 0;
while ((rowdata = taos_fetch_row(result)) != IntPtr.Zero)
{
queryRows++;
DataRow dr = dt.NewRow();
Console.Write(queryRows + "\t");
for (int index = 0; index < fieldCount; ++index)
{
TSDB_FIELD field = fields[index];
int offset = 8 * index;
IntPtr data = Marshal.ReadIntPtr(rowdata, offset);
if (data == IntPtr.Zero)
{
Console.Write("NULL");
continue;
}
dynamic v = new object();
switch ((TSDB_DATA_TYPE)field.type)
{
case TSDB_DATA_TYPE.BOOL:
//bool v1 = Marshal.ReadByte(data) == 0 ? false : true;
//Console.Write(v1);
v = Marshal.ReadByte(data) == 0 ? false : true;
break;
case TSDB_DATA_TYPE.TINYINT:
// byte v2 = Marshal.ReadByte(data);
//Console.Write(v2);
v = Marshal.ReadByte(data);
break;
case TSDB_DATA_TYPE.SMALLINT:
//short v3 = Marshal.ReadInt16(data);
//Console.Write(v3);
v = Marshal.ReadInt16(data);
break;
case TSDB_DATA_TYPE.INT:
//int v4 = Marshal.ReadInt32(data);
//Console.Write(v4);
v = Marshal.ReadInt32(data);
break;
case TSDB_DATA_TYPE.BIGINT:
//long v5 = Marshal.ReadInt64(data);
//Console.Write(v5);
v = Marshal.ReadInt64(data);
break;
case TSDB_DATA_TYPE.FLOAT:
//float v6 = (float)Marshal.PtrToStructure(data, typeof(float));
//Console.Write(v6);
v = (float)Marshal.PtrToStructure(data, typeof(float));
break;
case TSDB_DATA_TYPE.DOUBLE:
//double v7 = (double)Marshal.PtrToStructure(data, typeof(double));
//Console.Write(v7);
v = (double)Marshal.PtrToStructure(data, typeof(double));
break;
case TSDB_DATA_TYPE.BINARY:
//string v8 = Marshal.PtrToStringAnsi(data);
//Console.Write(v8);
v = Marshal.PtrToStringAnsi(data);
break;
case TSDB_DATA_TYPE.TIMESTAMP:
long v9 = Marshal.ReadInt64(data);
System.DateTime time = System.DateTime.MinValue;
System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1, 0, 0, 0));
time = startTime.AddMilliseconds(v9);
//Console.Write(Convert.ToDateTime(time));
v = time;
break;
case TSDB_DATA_TYPE.NCHAR:
//string v10 = Marshal.PtrToStringAnsi(data);
//Console.Write(v10);
v = Marshal.PtrToStringAnsi(data);
break;
}
Console.Write(v + "\t");
dr[index] = v;
}
Console.WriteLine("");
dt.Rows.Add(dr);
}
if (taos_errno(_taosConn) != 0)
{
Console.WriteLine("Query is not complete， Error {0:G}", taos_errno(_taosConn), Error(_taosConn));
}
else
{
Console.WriteLine("Query is complete");
}
taos_free_result(result);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
return(dt);
}