drop table OS_PROPERTYENTRY cascade constraints;drop table OS_USER cascade constraints;drop table OS_GROUP cascade constraints;drop table OS_MEMBERSHIP cascade constraints;drop table OS_WFENTRY cascade constraints;drop table OS_CURRENTSTEP cascade constraints;drop table OS_HISTORYSTEP cascade constraints;drop table OS_CURRENTSTEP_PREV cascade constraints;drop table OS_HISTORYSTEP_PREV cascade constraints;drop sequence seq_os_wfentry;drop sequence seq_os_currentsteps;create table OS_PROPERTYENTRY(	GLOBAL_KEY varchar(255),	ITEM_KEY varchar(255),	ITEM_TYPE smallint,	STRING_VALUE varchar(255),	DATE_VALUE date,	DATA_VALUE blob,	FLOAT_VALUE float,	NUMBER_VALUE numeric,	primary key (GLOBAL_KEY, ITEM_KEY));create table OS_USER(    USERNAME varchar(20),    PASSWORDHASH varchar(2024),    primary key (USERNAME));create table OS_GROUP(    GROUPNAME varchar(20),    primary key (GROUPNAME));create table OS_MEMBERSHIP(    USERNAME varchar(20),    GROUPNAME varchar(20),    primary key (USERNAME, GROUPNAME),    foreign key (USERNAME) references OS_USER(USERNAME),    foreign key (GROUPNAME) references OS_GROUP(GROUPNAME));create table OS_WFENTRY(    ID number,    NAME varchar(20),    STATE integer,    primary key (ID));create table OS_CURRENTSTEP(    ID number,    ENTRY_ID number,    STEP_ID integer,    ACTION_ID integer,    OWNER varchar(20),    START_DATE date,    FINISH_DATE date,    DUE_DATE date,    STATUS varchar(20),    CALLER varchar(20),    primary key (ID),    foreign key (ENTRY_ID) references OS_WFENTRY(ID),    foreign key (OWNER) references OS_USER(USERNAME),    foreign key (CALLER) references OS_USER(USERNAME));create table OS_HISTORYSTEP(    ID number,    ENTRY_ID number,    STEP_ID integer,    ACTION_ID integer,    OWNER varchar(20),    START_DATE date,    FINISH_DATE date,    DUE_DATE date,    STATUS varchar(20),    CALLER varchar(20),    primary key (ID),    foreign key (ENTRY_ID) references OS_WFENTRY(ID),    foreign key (OWNER) references OS_USER(USERNAME),    foreign key (CALLER) references OS_USER(USERNAME));create table OS_CURRENTSTEP_PREV(    ID number,    PREVIOUS_ID number,    primary key (ID, PREVIOUS_ID),    foreign key (ID) references OS_CURRENTSTEP(ID),    foreign key (PREVIOUS_ID) references OS_HISTORYSTEP(ID));create table OS_HISTORYSTEP_PREV(    ID number,    PREVIOUS_ID number,    primary key (ID, PREVIOUS_ID),    foreign key (ID) references OS_HISTORYSTEP(ID),    foreign key (PREVIOUS_ID) references OS_HISTORYSTEP(ID));create sequence seq_os_wfentry minvalue 10 increment by 10;create sequence seq_os_currentsteps;