Database

DbConnection.Open();
DataTable dt = DbConnection.GetSchema("Columns");
foreach (var col in dt.Columns) {
    Console.Write(col + "\t");
}
foreach (DataRow row in dt.Rows) {
    foreach (object field in row.ItemArray) {
        Console.Write(field + "\t");
    }
    Console.WriteLine();
}

TABLE_CAT
TABLE_SCHEM
TABLE_NAME
COLUMN_NAME
DATA_TYPE
TYPE_NAME
COLUMN_SIZE
BUFFER_LENGTH
DECIMAL_DIGITS
NUM_PREC_RADIX
NULLABLE
REMARKS
COLUMN_DEF
SQL_DATA_TYPE
SQL_DATETIME_SUB
CHAR_OCTET_LENGTH
ORDINAL_POSITION
IS_NULLABLE

select a.[transaction], b.tran_count
from transactiontable A
inner join (select [transaction], count(*) as tran_count from transactiontable group by [transaction]) as b 
on a.[trasaction] = b.[transaction];

Update MyTable Set Price=Price*1.05, ItemVolume=ItemVolume+100 Where Category='Electronics';