left-join

问题 I have the following table CREATE TABLE `prod_prices` ( `id` varchar(32) COLLATE utf8_unicode_ci NOT NULL, `date` date NOT NULL, `price` decimal(10,2) NOT NULL, PRIMARY KEY (`id`,`date`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; And some sample data INSERT INTO `prod_prices` (`id`, `date`, `price`) VALUES ('plan_a', '2012-06-15', 10.20), ('plan_a', '2012-06-16', 10.30), ('plan_b', '2012-06-15', 5.20), ('plan_b', '2012-06-16', 5.30), ('plan_b', '2012-06-17', 5.50); And want

问题 I have the following table CREATE TABLE `prod_prices` ( `id` varchar(32) COLLATE utf8_unicode_ci NOT NULL, `date` date NOT NULL, `price` decimal(10,2) NOT NULL, PRIMARY KEY (`id`,`date`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; And some sample data INSERT INTO `prod_prices` (`id`, `date`, `price`) VALUES ('plan_a', '2012-06-15', 10.20), ('plan_a', '2012-06-16', 10.30), ('plan_b', '2012-06-15', 5.20), ('plan_b', '2012-06-16', 5.30), ('plan_b', '2012-06-17', 5.50); And want

问题 I want to show the given records in the following table into the specific format which is shown below in the table. Creating table: Test_1 CREATE TABLE Test_1 ( ColumnA varchar, ColumnB varchar ); Insertion of records: INSERT INTO Test_1 values('A101','B101'),('A102','B102'), ('A103','B103'),('A104','B104'), ('A105','B105'),('A106','B106'), ('A107','B107'),('A108','B108'), ('A109','B109'),('A201','B201'); I want to show the result like this: Expected Result : ColumnA ColumnX -----------------

问题 How do I jeft.join 2 data frames based on the nearest date? I currently have the script written so that it joins by the exact date, but I would prefer to do it by nearest date in case there is not an exact match. This is what I currently have: MASTER_DATABASE <- left_join(ptnamesMID, CTDB, by = c("LAST_NAME", "FIRST_NAME", "Measure_date" = "VISIT_DATE")) 回答1: The rolling joins in the data.table have a parameter roll = "nearest" which does propably what the OP expects. Unfortunately, the OP

问题 How do I jeft.join 2 data frames based on the nearest date? I currently have the script written so that it joins by the exact date, but I would prefer to do it by nearest date in case there is not an exact match. This is what I currently have: MASTER_DATABASE <- left_join(ptnamesMID, CTDB, by = c("LAST_NAME", "FIRST_NAME", "Measure_date" = "VISIT_DATE")) 回答1: The rolling joins in the data.table have a parameter roll = "nearest" which does propably what the OP expects. Unfortunately, the OP

问题 I have an application that connects to multiple server. where one server will have ID that are foreign key to a table that is located on a different server. The issue here is that MySQL does not support linked servers so I can't run a left query that will LEFT join 2 tables located on separate servers. So I have to pull 2 separate queries from 2 different server using PHP and they LEFT JOINing them using PHP. Please note that the array keys listed below needs to be dynamic. I can't use a

问题 I have a join query where I left join 2 tables say tab_sector and tab_sector_subdivisions . I have records in first table which may or may not have corresponding records in 2nd table. I am joining these tables in such a way that Its should return all row from first table and matching row from 2nd table. Also if a row in first table has multiple record in 2nd table, it should return as GROUP_CONCAT(field_name) . But my query doesn't return the way I need. Here is the query without GROUP_CONCAT

问题 I am having problems running a query without either truncating the note field in NotesTbl or returning repeated entries. UID is not unique for AccessTbl. When I leave out "distinct" notes will return multiple times because I am joining with AccessTbl on a non-distinct condition. When I use distict, the note field is trunctated because it is a memo field. Here is my query: SELECT DISTINCT NotesTbl.pin, NotesTbl.noteid, NotesTbl.note, NotesTbl.date, AccessTbl.affiliation, AccessTbl.name FROM

问题 I´m trying to fill the gaps after using group by using an aux table, can you help? aux table to deal with days with no orders date quantity 2014-01-01 0 2014-01-02 0 2014-01-03 0 2014-01-04 0 2014-01-05 0 2014-01-06 0 2014-01-07 0 group by result from "orders" table date quantity 2014-01-01 7 2014-01-02 1 2014-01-04 2 2014-01-05 3 desired result joining "orders" table with "aux table" date quantity 2014-01-01 7 2014-01-02 1 2014-01-03 0 2014-01-04 2 2014-01-05 3 2014-01-06 0 2014-01-07 0 回答1:

问题 I´m trying to fill the gaps after using group by using an aux table, can you help? aux table to deal with days with no orders date quantity 2014-01-01 0 2014-01-02 0 2014-01-03 0 2014-01-04 0 2014-01-05 0 2014-01-06 0 2014-01-07 0 group by result from "orders" table date quantity 2014-01-01 7 2014-01-02 1 2014-01-04 2 2014-01-05 3 desired result joining "orders" table with "aux table" date quantity 2014-01-01 7 2014-01-02 1 2014-01-03 0 2014-01-04 2 2014-01-05 3 2014-01-06 0 2014-01-07 0 回答1: