I have 2 tables,
first contains articles, second contains quantities. the two tables are linked with the "kodex" column. The second table can have multiple records for the same item, but can also have none.
what I need is a query that lists the entire first table, and adds an additional column that contains the sum of all quantities of all entries in the second table.
I have done this with left join on the kodex table, and works fine, but only as long as i do not add the sum() on the select statement. as soon as I do so, it lists only the rows that have a match on the second table.
Query that displays all rows:
SELECT b.* FROM `bestehend` as b left join eingelesen as e on e.kodex=b.kodex
query that displays only rows with matching entries in the second table:
SELECT b.*, sum(e.menge) as gesmenge FROM `bestehend` as b left join eingelesen as e on e.kodex=b.kodex
what I would need is the behaviour of the first query, with the additional column gesmenge from the second query.
thanks!
Update your query
SELECT b.*, sum(e.menge) as gesmenge FROM `bestehend` as b left join eingelesen as e on e.kodex=b.kodex
with adding group by b.article_id. Group by is needed so query know how to summarize all quantities of all entries in the second table.
Final query should look like
SELECT b.*, sum(e.menge) as gesmenge FROM `bestehend` as b left join eingelesen as e on e.kodex=b.kodex group by b.article_id
Related
I have two table Table-A and Table-B as given in picture.I want to join Table-A and Table-B on the column UIN.In table-A some records in column UIN contains null value. I want to include those records.My output should look like Table-C.I tried it by join these table but it does not including the receord which have null value of UIN in Table-A. Can any one help me out
Click here for table
you can either use full outer join or left join, depending on what you want to do when there are ids in Table B which are not present in Table A
select *
from A full outer join B
on A.UIN = B.UIN
or
select *
from A left join B
on A.UIN = B.UIN
How can I unite two select statement in one table result?
For instance in the first table I want to get everything however on my 2nd table I only want the corel name that is equal to the corel_id and id of my 2nd table?
SELECT *
FROM garage
UNION
SELECT c.name
FROM corel as c
WHERE EXISTS (SELECT 1 FROM garage as g WHERE c.id = g.corel_id
I tried to execute this but this did not work. Is this right? or is there a better way to do this?
Sorry newbie here.
UPDATE EXPECTED RESULT :
https://anotepad.com/notes/b6662w
Give this a try:
SELECT g.*, c.name
FROM garage g
LEFT JOIN corel c
ON c.id = g.corel_id
Matching two tables in a database is called a join. An inner join, the default, returns only the rows that match from both tables.
A left join returns all the rows from the first table whether or not they match the second, and any data from the second table that matches. The right join does the inverse, returning only non-matching data from the second table. There is also the full join that returns all data regardless of match.
A join statement is what you need. A join puts columns from multiple tables into rows together based in the matching conditions in the where clause.
A union requires 2 or more queries to have the same columns. The union puts the sets of rows together into a longer set or rows.
In one of my PHP application, I use left join between two MySQL tables using the following query:
SELECT bs.question_code, bs.question_english, count( st.id ) sqid
FROM bs_qbank_question bs
LEFT JOIN bs_qbank_question_study_link st
ON bs.id = st.question_id
The problem is, it selects only those rows from bs_qbank_question that have at least one row in bs_qbank_question_study_link table. If there is no data for a particular row of bs_qbank_question in bs_qbank_question_study_link then that row is not selected.
But I need to select each row from bs_qbank_question and also need one column for each row from bs_qbank_question_study_link as count the total occurrence of that row.
Can anyone tell me what's wrong with my query and how can I replace count( st.id ) as 0 if there is no data for any row?
- Thanks
I need to fetch data from 5 tables(all columns of each table) all have FK, which is PK of single table.
But some of the tables may have record may be empty.If data is present on the respective column/table it should return otherwise null/default value
There is one to many and one to one relations on the child tables with parent table.
I have tried so far
- UNION which has concern of same number of columns
- CROSS JOIN not returning any data
- SELECT ALL_COLUMN FROM ALL_TABLE WHERE TABLE.FK=ID Not returning any data
- LEFT JOIN working for 2 tables but not more than that
SELECT A.GENDER, B.BLOCKED_USER FROM t_macroworld_registration AS A
LEFT JOIN t_macroworld_blacklist AS B ON 1=1 WHERE A.ID=15
What are the possible ways I can implement this in a view in MySQL.
Outer join operations are the normative pattern...
SELECT ...
FROM a
LEFT JOIN b ON b.a_id = a.id
LEFT JOIN c ON c.a_id = a.id
LEFT JOIN d ON d.a_id = a.id
WHERE a.id = 15
It's important for the predicates on the outer joined tables to be in the ON clause and not the WHERE clause. If there's any predicate in the WHERE clause requires that a value from one of the outer joined tables be non-NULL, that will negate the "outerness" of the join, making it into an inner join.
The "big rock" problem with this the result when there are more than one matching rows in b, c and d. If there's five rows from b that match, and three rows from c that match, and two rows from b that match, it's going to look like a lot of duplicates. (5x3x2 = 30 rows to be returned, with a lot of duplicated data on those rows.)
Finally I have solved It,
I broke the whole thing into many select query based on FK from each table, so number of additional row returns and mapping has become easy.
Who ever is getting this kind of problem, if it is possible then break it into many select query instead of one.
SELECT
w.id,w.name,a.address,i.name,i.quantity
FROM
warehouse w
LEFT JOIN address AS a ON a.warehouse_id = w.id
LEFT JOIN item AS i ON i.warehouse_id = w.id
LEFT JOIN order AS o ON o.item_id = i.id
WHERE
w.id = 1
GROUP BY 1,2,3,4;
Will give you an overview of your stock and orders for your warehouses. This will also duplicate some results.
Assuming 2 warehouses, 1 address for each, 3 items per warehouse, 2 orders by item = 2 * 3 * 2 = 12 lines
I recommend adding your LEFT JOIN stage by stage and visualizing the result for each stage. You'll quickly understand why lines are multiplying.
Note the usage of foreign keys and ids in the tables to link the tables.
Good luck
(Main table id equal to jid. Join based on that.)
The 1st item has got 2 row in the join table. /That's great./
But 3rd item has got no row in join table.
The question: How can i ignore those items that has got no joined rows? IN ONE QUERY.
I tried the following:
SELECT *
FROM mainTable AS mainT
LEFT JOIN joinTable AS joinT ON mainT.id=joinT.jid
WHERE COUNT(joinT.id) > 0
Replace LEFT JOIN with INNER JOIN, and remove the WHERE clause.