lateral

目前 hive 支持的复合数据类型有以下几种： map (key1, value1, key2, value2, ...) Creates a map with the given key/value pairs struct (val1, val2, val3, ...) Creates a struct with the given field values. Struct field names will be col1, col2, ... named_struct (name1, val1, name2, val2, ...) Creates a struct with the given field names and values. (as of Hive 0.8.0) array (val1, val2, ...) Creates an array with the given elements create_union (tag, val1, val2, ...) Creates a union type with the value that is being pointed to by the tag parameter 一、map、struct、array 这3种的用法： 1、Array的使用 创建数据库表，以array作为数据类型 create table

I have a function called generate_table, that takes 2 input parameters ( rundate::date and branch::varchar ) Now I am trying to work on a second function, using PLPGSQL, that will get a list of all branches and the newest date for each branch and pass this as a parameter to the generate_table function. The query that I have is this: select max(rundate) as rundate, branch from t_index_of_imported_files group by branch and it results on this: rundate;branch 2014-03-13;branch1 2014-03-12;branch2 2014-03-10;branch3 2014-03-13;branch4 and what I need is that the function run something like this

I'd like to convert single rows into multiple rows in PostgreSQL, where some of the columns are removed. Here's an example of the current output: name | st | ot | dt | -----|----|----|----| Fred | 8 | 2 | 3 | Jane | 8 | 1 | 0 | Samm | 8 | 0 | 6 | Alex | 8 | 0 | 0 | Using the following query: SELECT name, st, ot, dt FROM times; And here's what I want: name | t | val | -----|----|-----| Fred | st | 8 | Fred | ot | 2 | Fred | dt | 3 | Jane | st | 8 | Jane | ot | 1 | Samm | st | 8 | Samm | dt | 6 | Alex | st | 8 | How can I modify the query to get the above desired output? SELECT times.name, x.t,

I have a table of rows with the following structure name TEXT, favorite_colors TEXT[], group_name INTEGER where each row has a list of everyone's favorite colors and the group that person belongs to. How can I GROUP BY group_name and return a list of the most common colors in each group? Could you do a combination of int[] && int[] to set for overlap, int[] & int[] to get the intersection and then something else to count and rank? Quick and dirty: SELECT group_name, color, count(*) AS ct FROM ( SELECT group_name, unnest(favorite_colors) AS color FROM tbl ) sub GROUP BY 1,2 ORDER BY 1,3 DESC;

Recently upgraded to using PostgreSQL 9.3.1 to leverage the JSONfunctionalities. In my table I have a json type column that has a structure like this: { "id": "123", "name": "foo", "emails":[ { "id": "123", "address": "somethinghere" }, { "id": "456", "address": "soemthing" } ] } This is just dummy data for the purpose of the question. Is it possible to query for a specific item in the emails array based on the id? Pretty much: "return email where id=123)"? Erwin Brandstetter Yes, that's possible: SELECT * FROM tbl t, json_array_elements(t.json_col->'emails') AS elem WHERE elem->>'id' = 123;

I need to migrate SQL queries written for MS SQL Server 2005 to Postgres 9.1. What is the best way to substitute for CROSS APPLY in this query? SELECT * FROM V_CitizenVersions CROSS APPLY dbo.GetCitizenRecModified(Citizen, LastName, FirstName, MiddleName, BirthYear, BirthMonth, BirthDay, ..... ) -- lots of params GetCitizenRecModified() function is a table valued function. I can't place code of this function because it's really enormous, it makes some difficult computations and I can't abandon it. Erwin Brandstetter In Postgres 9.3 or later use a LATERAL join: SELECT v.col_a, v.col_b, f.* --