using (FirebirdSql.Data.FirebirdClient.FbConnection con = new FirebirdSql.Data.FirebirdClient.FbConnection(connect))
            {
                con.Open();
                FirebirdSql.Data.FirebirdClient.FbTransaction fbTransaction = con.BeginTransaction();

                FirebirdSql.Data.FirebirdClient.FbCommand com = new FirebirdSql.Data.FirebirdClient.FbCommand(zapr, con, fbTransaction);

                using (FirebirdSql.Data.FirebirdClient.FbDataReader fdr = com.ExecuteReader())
                {

                    dt.Load(fdr, LoadOption.OverwriteChanges);
                    fdr.Close();
                }                
                con.Close();
                fbTransaction.Dispose();
            }

CREATE TABLE T_PACIENT (
    ID          INTEGER NOT NULL,
    FIO         VARCHAR(30),
    FAM         VARCHAR(30),
    NAME        VARCHAR(30),
    OTCH        VARCHAR(30),
    SEX         CHAR(1),
    DDROGD      TIMESTAMP,
    NOMOMS      VARCHAR(30),
    NOMDMS      VARCHAR(30),
    SKIDKA      DOUBLE PRECISION,
    ID_PASPORT  INTEGER,
    ADRES       VARCHAR(200),
    KOMMENT     VARCHAR(300),
    DEL         SMALLINT,
    US_ID       INTEGER,
    DDTT        TIMESTAMP
);
CREATE TABLE T_PRIEMS (
    ID          INTEGER NOT NULL,
    DDPRIEM     TIMESTAMP,
    ID_PACIENT  INTEGER,
    ID_KASSIR   INTEGER,
    ID_USLUG    INTEGER,
    ID_DOKTOR   INTEGER,
    CENA        DOUBLE PRECISION,
    SKIDKA      DOUBLE PRECISION,
    NOMER       INTEGER,
    DEL         SMALLINT,
    US_ID       INTEGER,
    DDTT        TIMESTAMP
);
CREATE TABLE T_SOTR (
    ID        INTEGER NOT NULL,
    FIO       VARCHAR(30),
    FAM       VARCHAR(30),
    NAME      VARCHAR(30),
    OTCH      VARCHAR(30),
    ID_DOLG   INTEGER,
    DDPRIOM   TIMESTAMP,
    TABNOMER  INTEGER,
    DDUVOLEN  TIMESTAMP,
    DDROGD    TIMESTAMP,
    KONTINF   VARCHAR(300),
    DEL       SMALLINT,
    US_ID     INTEGER,
    DDTT      TIMESTAMP
);
CREATE TABLE T_USER (
    ID       INTEGER NOT NULL,
    FIO      VARCHAR(30),
    FAM      VARCHAR(30),
    NAME     VARCHAR(30),
    OTCH     VARCHAR(30),
    PASSW    VARCHAR(20),
    ID_DOLG  INTEGER,
    DEL      SMALLINT,
    US_ID    INTEGER,
    DDTT     TIMESTAMP
);

CREATE OR ALTER VIEW V_PRIEMS(
    ID,
    DDPRIEM,
    ID_PACIENT,
    FIO,
    DDROGD,
    ID_KASSIR,
    KAS_FIO,
    ID_DOKTOR,
    DOK_FIO,
    NOMER)
AS
select tp.id,tp.ddpriem, tp.id_pacient, tpac.fio, tpac.ddrogd, tp.id_kassir, tus.fio as "kas_fio",tp.id_doktor,tos.fio as "dok_fio",tp.nomer
from t_priems tp, t_pacient tpac, t_user tus, t_sotr tos
where (tp.id_pacient = tpac.id) and(tp.id_kassir = tus.id) and (tos.id = tp.id_doktor)

select ID, DDPRIEM, ID_PACIENT, FIO, DDROGD, ID_KASSIR, KAS_FIO, ID_DOKTOR, DOK_FIO, NOMER 
from v_priems 
where (ddpriem between '15.12.2014 00:00' and '05.02.2015 23:59') order by ddpriem