ARRAY JOIN本质上等同于INNERT JOIN数组。 创建tbl_test_array_join表: create table tbl_test_array_join(str String, arr Array(Int8)) engine=Memory; 插入数据: insert into tbl_test_array_join(str,arr) values('a',[1,3,5]),('b',[
可同时ARRAY JOIN多个数组，这种情况下得到的结果并非笛卡尔积。也可以ARRAY JOIN Nested类型。DISTINCT：如果需要只对某几列去重，需用DISTINCTON(column1,column2..)，否则视作对全部列去重。DISTINCT子句是先于ORDER BY子句执行的。与不使用聚合函数而对某些列进行GROUPBY相比，结果一般是相同的，但使用DISTINCT时，已...
ARRAY JOIN [('android', '1.1', 2001), ('android', '1.1', 3002), ('android', '1.1', 1003), ('android', '1.1', 3004)] AS a ) GROUP BY platform, ver UNION ALL SELECT platform, ver, uniqCombinedState(uid) AS xx FROM ( SELECT a.1 AS platform, a.2 AS ver, a.3 AS uid ...
inner array join(默认):排除掉了空数组 left aray join:在inner array join中被排除掉的空数组出现在了返回的结果集中 当同时对多个数组字段进行array join操作,查询的计算逻辑按行合并而不是产生笛卡尔积 droptableifexiststest_arrayjoin;CREATETABLEtest_arrayjoin(idString,hobbyArray(String))ENGINE=Memory;inse...
1、等同于innert join;使查询与数组和nested类型连接,类似array join函数 2、一个查询只能出现一个array join,where/prewhere使用array join子句,其将优先于where/prewhere子句执行,否则将在where/prewhere子句之后执行 SELECT * FROM arrays_test ┌─s───────┬─arr─────┐ ...
[WITH expr_list|(subquery)]SELECT[DISTINCT]expr_list[FROM [db.]table|(subquery)|table_function][FINAL][SAMPLE sample_coeff][ARRAY JOIN ...][GLOBAL][ANY|ALL|ASOF][INNER|LEFT|RIGHT|FULL|CROSS][OUTER|SEMI|ANTI]JOIN(subquery)|table(ON<expr_list>)|(USING<column_list>)[PREWHERE expr][WHERE...
[WITH expr_list|(subquery)] SELECT [DISTINCT] expr_list [FROM [db.]table | (subquery) | table_function] [FINAL] [SAMPLE sample_coeff] [ARRAY JOIN ...] [GLOBAL] [ANY|ALL|ASOF] [INNER|LEFT|RIGHT|FULL|CROSS] [OUTER|SEMI|ANTI] JOIN (subquery)|table (ON <expr_list>)|(USING <colum...
{ ... } if (expressions.array_join) { ... } if (...
示例: SELECT arrayMap(x -> (x + 2), [1, 2, 3]) as res; 返回[3,4,5] SELECT arrayMap((x, y) -> (x, y), [1, 2, 3], [4, 5, 6]) AS res 返回[(1,4),(2,5),(3,6)] arrayJoin 函数获取每一行并将他们展开到多行(unfold)。行转列函数。 arraySort: 排序,语法为array...
[FROM[database_name.]table| (subquery) | table_function] [FINAL] [SAMPLE sample_coeff] [ARRAYJOIN...] [GLOBAL] [ANY|ALL|ASOF] [INNER|LEFT|RIGHT|FULL|CROSS] [OUTER|SEMI|ANTI]JOIN(subquery)|table(ON<expr_list>)|(USING<column_list>) ...