full-outer-join

问题 I am doing full outer join on 4 tables on the same column. I want to generate only 1 row for each different value in the Join column. Inputs are: employee1 +---------------------+-----------------+--+ | employee1.personid | employee1.name | +---------------------+-----------------+--+ | 111 | aaa | | 222 | bbb | | 333 | ccc | +---------------------+-----------------+--+ employee2 +---------------------+----------------+--+ | employee2.personid | employee2.sal | +---------------------+--------

问题 So apparently mySQL doesn't support full outer join, but it's really what I need. I've seen a bunch of blog posts and articles about emulating it with unions, but that removes duplicates. Can anyone help me out here? Here's the query containing the full outer join (only one of a number of joins being done here); how would I translate that into something mySQL understands? SELECT DISTINCT n.title, nr.teaser, n.nid, DATE_FORMAT(FROM_UNIXTIME(n.created), '%M %e, %Y') AS date, f.filepath AS image

问题 So apparently mySQL doesn't support full outer join, but it's really what I need. I've seen a bunch of blog posts and articles about emulating it with unions, but that removes duplicates. Can anyone help me out here? Here's the query containing the full outer join (only one of a number of joins being done here); how would I translate that into something mySQL understands? SELECT DISTINCT n.title, nr.teaser, n.nid, DATE_FORMAT(FROM_UNIXTIME(n.created), '%M %e, %Y') AS date, f.filepath AS image

问题 This topic is related to my previews one Join two tables with all records I'm tryng now to join 3 or more tables in my Laravel controller code, and view them in one Datatable. table1 +--------------------+---------+ | recordtime | tempout | +--------------------+---------+ | 4.12.2020 10:00:00 | 1.1 | | 4.12.2020 10:30:00 | 1.2 | | 4.12.2020 11:00:00 | 1.3 | | 4.12.2020 11:30:00 | 1.4 | | 4.12.2020 12:00:00 | 1.5 | +--------------------+---------+ table2 +--------------------+---------+ |

问题 I am building a WPF application that monitors a directory on the users computer. The app uploads files from the monitored directory and then saves off some information into a SQLite db. Part of the business processing is to not re-process files that have already been uploaded and to re-upload files that have been uploaded but have changed since the last upload. I have two helper methods that build and return a List<FileMetaData> that I used LINQ - Full Outer Join to join the. My problem is

问题 I am building a WPF application that monitors a directory on the users computer. The app uploads files from the monitored directory and then saves off some information into a SQLite db. Part of the business processing is to not re-process files that have already been uploaded and to re-upload files that have been uploaded but have changed since the last upload. I have two helper methods that build and return a List<FileMetaData> that I used LINQ - Full Outer Join to join the. My problem is

问题 How would one carry out a full outer join on three tables? I have already carried my join successfully on two tables, but I am clueless on how to add the third table to my query. Here is my (long-winded) query: SELECT MONTH(t1.datetime) AS month, COUNT(DISTINCT t1.column) AS t1Count, COUNT(DISTINCT t2.column) AS t2Count FROM t1 LEFT OUTER JOIN t2 ON MONTH(t2.datetime) = MONTH(t1.datetime) GROUP BY MONTH(t1.datetime) UNION SELECT MONTH(t1.datetime) AS month, COUNT(DISTINCT t1.column) AS

问题 How would one carry out a full outer join on three tables? I have already carried my join successfully on two tables, but I am clueless on how to add the third table to my query. Here is my (long-winded) query: SELECT MONTH(t1.datetime) AS month, COUNT(DISTINCT t1.column) AS t1Count, COUNT(DISTINCT t2.column) AS t2Count FROM t1 LEFT OUTER JOIN t2 ON MONTH(t2.datetime) = MONTH(t1.datetime) GROUP BY MONTH(t1.datetime) UNION SELECT MONTH(t1.datetime) AS month, COUNT(DISTINCT t1.column) AS

问题 EDIT: An extension to this question can be found here I want to join four different tables with SQLite which have just two columns in common. Please take a look at following example +--------+---+-----+-----+ | table1 | | | | +--------+---+-----+-----+ | a | b | lon | lat | +--------+---+-----+-----+ | 1 | 2 | 111 | 222 | +--------+---+-----+-----+ +--------+---+-----+-----+ | table2 | | | | +--------+---+-----+-----+ | c | d | lon | lat | +--------+---+-----+-----+ | 3 | 4 | 333 | 444 | +---

问题 I have a table that contains multiple records for multiple dates. I am trying to see the difference between "date 1" and "date 2" and my full outer join is not returning the data I was expecting. I know there are 13278 rows on date 1 and 13282 on date 2 - therefore I would expect to see at least 13282 rows, but I get back 13195...which is an INNER JOIN (I tested this). I am hoping for results like: 001 000123 009 NULL 1000 001 000124 009 1000 1000 001 000125 009 1000 1000 001 000126 009 1000