hive中select * from 涉及计算 统计 需要给键启动MapReduce;不是映射,拿到是一键一值 cte和嵌套查询 cte 语法 with t1 as (select ...) select * from t1 实例 with t1 as (select order_customer from orders group by order_customer_id) select c.customer_id,concat(customer_fname,'.',customer_lna...
-- 基本CTE with new_table as (select * from student where sex='male') select name,age,money,sex from new_table; -- from前置CTE with new_table as (select * from student where sex='female') from new_table select name,age,money,sex; -- 链式调用的CTE with new_tb1 as (select name...
CREATE TABLE tbl_name AS SELECT ...; 删除表 DROP TABLE tbl; 修改表 重命名 ALTER TABLE old RENAME TO new; 修改属性 ALTER TABLE tbl SET TBLPROPERTIES(key=value); -- 常用属性 ("EXTERNAL"="TRUE") -- 内外部表,TRUE表示外部表 ('comment' = new_comment) -- 修改表注释 ...
1.with子句必须在引用的select语句之前定义,而且后面必须要跟select查询,否则报错。 2.with as后面不能加分号,with关键字在同级中只能使用一次,允许跟多个子句,用逗号隔开,最后一个子句与后面的查询语句之间只能用右括号分隔,不能用逗号。 createtabletable_newaswitht1as(select*fromtable_first ), t2as(select*fr...
select t1.name,t1.age,t1.prefer,t1.height,t1.nationfrom(select data from test_table1)t0 lateral viewjson_tuple(t0.data,'name','age','prefer','height','nation')t1asname,age,prefer,height,nation; 解析结果: get_json_object函数 & json_tuple函数 ...
hive中使用with as查询作为临时中间表 oracle、hive都存在with as的用法。用于将重复的查询结果复用。 今天做统计分析时用到,使用例子如下: 1. 直接查询 withtmp_aas(selectf1,f2,f3fromtest1 )selectf1,f2,f3fromtmp_a; 2. 多表计算结果join withtmp_aas(selectf1,f2,f3fromtest1...
WITH cte_name1 AS (select_statement1), cte_name2 AS (select statment2) sql_containing_cte_name: cte_name 是公共表表达式的名字; select_statement是一个完整的SELECT语句; sql_containing_cte_name是包含了刚刚定义的公共表表达式的SQL语句; CTE 的 scope 生命周期是with 子句后的单条 select/insert 语句...
SELECT Year, Month, Day, Hours, Minutes, cast((cast(Seconds as int)/15) as int)*15 AS secondMod, Count(*) AS PerCount FROM LoggerTable GROUP BY Year, Month, Day, Hours, Minutes, secondMod ORDER BY PerCount; the above query fails with an error FAILED: Error in semantic analysis:...
-- 错误情况 select age ,gender -- gender未出现在group by中 ,count(1) as cnt from temp1 group by age -- 正确使用 select age ,gender -- gender需出现在group by中 ,count(1) as cnt from temp1 group by age ,gender 在进行等值判断时,SQL默认会将数值型字符串转为double型后判断,减少类型转...
withtempas(select*fromeventwhereevent_key="Get"orevent_key="Set")selectsum(casewhenevent_key="Get"then1else0end)asget_num,sum(casewhenevent_key="Set"then1else0end)asSet_numfromtemp 阅读性是否比之前有所提高?此外,这条语句只对event表进行了一次扫描,将符合条件的数据存入temp中供后续计算, ...