TSQLColumnInfo

Class Description

                                                                      
 TSQLColumnInfo

 Contains information about single column from SQL table
 Has following methods:
   GetTypeName() - field type name in string form as it is reported by correspondent
          database method. Some databases providing full type name like "numeric(20)",
          other showing only "NUMERIC". As a result, one cannot use this string directly
          to create new field of similar types in other table 
   IsNullable() - says if field value can be NULL or not
   GetSQLType() - returns kind of sql type. Possible values:
      TSQLServer::kSQL_NONE        data type unknown
      TSQLServer::kSQL_CHAR        CHAR(n) - string with fixed length n
      TSQLServer::kSQL_VARCHAR     VARCHAR(n) - string with variable length upto n
      TSQLServer::kSQL_INTEGER     INTEGER, INT, TINYINT - any integer types
      TSQLServer::kSQL_FLOAT       FLOAT - float value
      TSQLServer::kSQL_DOUBLE      DOUBLE - double precision value
      TSQLServer::kSQL_NUMERIC     NUMERIC(n,s), NUMBER(n,s) - numeric values with length and precion
      TSQLServer::kSQL_BINARY      BLOB, VARBINARY  - binary data (vriable or fixed size)
      TSQLServer::kSQL_TIMESTAMP   TIMESTAMP - time and date stamp
   GetSize() - size of field in database. -1 if not known.
   GetLength() - length argument in type declaration like CHAR(len) or NUMERIC(len), -1 if not defined
   GetScale() - second argument in declarations like NUMERIC(len, s), -1 if not defined
   GetSigned() - is type signed(==1) or unsigned(==0), -1 if not defined