排序和分组--SQL 创建表雇员(EMP_ID CHAR(9)NOT NULL,F_NAME VARCHAR(15)NOT NULL,L_NAME VARCHAR(15)NOT NULL,SSN CHAR(9),B_DATE DATE,SEX CHAR,ADDRESS VARCHAR(30),JOB_ID CHAR(9 ),SALARY DECIMAL(10,2),MANAGER_ID CHAR(9),DEP_ID CHAR(9)NOT NULL,主键(EMP_ID)); 创建表JOB_HISTORY(EMPL_ID CHAR(9)非空,START_DATE DATE,JOBS_ID CH