paqsmm小学二年级下册数学期末试卷人教版 北师版.pptVIP

单行函数;目标;SQL 函数;两种 SQL 函数;单行函数;单行函数;字符函数;函数;大小写控制函数;CONCAT(Hello, World) SUBSTR(HelloWorld,1,5) LENGTH(HelloWorld) INSTR(HelloWorld, W) LPAD(salary,10,*) RPAD(salary, 10, *) TRIM(H FROM HelloWorld);SELECT employee_id, CONCAT(first_name, last_name) NAME, job_id, LENGTH (last_name), INSTR(last_name, a) Contains a? FROM employees WHERE SUBSTR(job_id, 4) = REP;;数字函数;SELECT ROUND(45.923,2), ROUND(45.923,0), ROUND(45.923,-1) FROM DUAL;;SELECT TRUNC(45.923,2), TRUNC(45.923), TRUNC(45.923,-2) FROM DUAL;;SELECT last_name, salary, MOD(salary, 5000) FROM employees WHERE job_id = SA_REP;;日期;日期;日期的数学运算;日期的数学运算;日期函数;MONTHS_BETWEEN (01-SEP-95,11-JAN-94);ROUND(SYSDATE,MONTH) 01-AUG-95;转换函数;隐式数据类型转换;隐式数据类型转换;显式数据类型转换;TO_CHAR 函数对日期的转换;YYYY;日期格式的元素;TO_CHAR 函数对日期的转换;TO_CHAR 函数对数字的转换;SELECT TO_CHAR(salary, $99,999.00) SALARY FROM employees WHERE last_name = Ernst;;TO_NUMBER 和 TO_DATE 函数 ;TO_NUMBER 和 TO_DATE 函数 ;RR 日期格式;RR 日期格式;嵌套函数; ;通用函数;NVL 函数; ; ; ;使用 COALESCE 函数;SELECT last_name, COALESCE(commission_pct, salary, 10) comm FROM employees ORDER BY commission_pct;;条件表达式;CASE 表达式;SELECT last_name, job_id, salary, CASE job_id WHEN IT_PROG THEN 1.10*salary WHEN ST_CLERK THEN 1.15*salary WHEN SA_REP THEN 1.20*salary ELSE salary END REVISED_SALARY FROM employees;;DECODE 函数;DECODE 函数;DECODE 函数;总结