I have a table with a bunch of orders... one of the columns is order_status. The data in that column ranges from 1 to 5. Each number relates to a name, which is stored in another table that relates that number to the respective name.
SELECT order_id , order_status FROM tablename1
The above would just return the numbers 1,2,3,4,5 for order status. How can i query within the query on the fly to replace these numbers with their respective names.
Also, what's the term used to describe this. I'd Google it if i knew what the appropriate term was.
Each number relates to a name, which is stored in another table that
relates that number to the respective name.
JOIN it with the other table:
SELECT
t.order_id,
s.StatusName
FROM tablename1 AS t
INNER JOIN the statusesTable AS s ON t.order_status = s.status_id;
Related
I have table emails_grouping in that I have one column named 'to_ids' this column contains multiple employee Id's . Now I want to change that Id's with respective employee names. employee data is in employee table.
this is in mysql.
I tried multiple ways but I'm not able to replace id's with names because , that 'to_ids' column contains multiple 'Ids'.
description to_ids
'Inactive Employees with missing Last working day', '11041,11109,899,13375,1715,1026'
above is the column which I want to change Id's with employee names.
This problem should demonstrate to you why it's a bad idea to store "lists" of id's like you're doing. You should instead store one id per row.
You can join to your employee table like this:
SELECT e.name
FROM emails_grouping AS g
JOIN employee AS e
ON FIND_IN_SET(e.id, g.to_ids)
WHERE g.description = 'Inactive Employees with missing Last working day';
But be aware that joining using a function like this is not possible to optimize. It will have very slow performance, because it can't look up the respective employee id's using an index. It has to do a table-scan of the employee table, and evaluate the id's against your comma-separated list one by one.
This is just one reason why using comma-separated lists instead of normal columns is trouble. See my answer to Is storing a delimited list in a database column really that bad?
I read the previous posts but I couldn't find one that answered my question.
What would be the name of the table that is made by joining two tables? The reason why I need the name is because I would like to change the column name of the new table using the ALTER TABLE (Table name) RENAME COLUMN (A) to (B). If there is no specified name, how can I name the new table?
ex
SELECT
client_id
,last_name
FROM INDIVIDUAL_CLIENT
UNION ALL
SELECT
client_id
,bus_name
FROM BUSINESS_CLIENT;
I would like to rename the column to last_name/bus_name instead of last_name
In the case of a query what temporal table a query might create internally is not relevant, because you a making a query and getting data back, it doesn't stay in the database as a table, there is no such table. Unless we make it.
if You want TSQL to change a column name it would affect your union query and I base my answer on Your
'I would like to rename the column to last_name/bus_name instead of last_name'
And think this is what you're looking for. Please correct me if it isn't.
In generic SQL what we're doing is putting a label on both projections that are to be displayed in the same column
SELECT
client_id
,last_name [last_name/ bus_name]
FROM INDIVIDUAL_CLIENT
UNION ALL
SELECT
client_id
,bus_name [last_name/ bus_name]
FROM BUSINESS_CLIENT;
update, in MySQL notation uses AS and quotes instead of angle brackets
SELECT
client_id
,last_name as "last_name/ bus_name"
FROM INDIVIDUAL_CLIENT
UNION ALL
SELECT
client_id
,bus_name as "last_name/ bus_name"
FROM BUSINESS_CLIENT;
I have a query i have been working on trying to get a specific set of data, join the comments in duplicate phone numbers of said data, then join separate tables based on a common field "entry_id" which also happens to be the number on the end of the word custom_ to pull up that table.
table named list and tables containing the values i want to join is custom_entry_id (with entry_id being a field in list in which i need the values of each record to replace the words in order to pull up that specific table) i need entry_id from the beginning part of my query to stick onto the end of the word custom for every value my search returns to get the fields from that custom table designated for that record. so it will have to do some sort of loop i guess? sorry like i said I am at a loss at this point
this is where i am so far:
SELECT * ,
group_concat(comments SEPARATOR '\r\n\r\n') AS comments_combined
FROM list WHERE `status` IN ("SALEA","SALE")
GROUP BY phone_number
//entry_id is included in the * as well as status
// group concat combines the comments if numbers are same
i have also experimented on test data with doing a full outer join which doesnt really exist. i feel if you can solve the other part for me i can do the joining of the data with a query similar to this.
SELECT * FROM test
LEFT JOIN custom_sally ON test.num = custom_sally.num
UNION
SELECT * FROM test
RIGHT JOIN custom_sally ON test.num = custom_sally.num
i would like all of this to appear with every field from my list table in addition to all the fields in the custom_'entry_id' tables for each specific record. I am ok with values being null for records that have different custom fields. so if record 1 has custom fields after the join of hats and trousers and record 2 has socks and shoes i realize that socks and shoes for record 1 will be null and hats and trousers for record 2 will be null.
i am doing all this in phpmyadmin under the SQL tab.
if that is a mistake please advise as well. i am using it because ive only been working with SQl for a few months. from what i read its the rookie tool.
i might be going about this all wrong if so please advise
an example
i query list with my query i get 20,000 rows with columns like status, phone_number, comments, entry_id, name, address, so on.
now i want to join this query with custom fields in another table.
the problem is the custom tables' names are all linked to the entry_id.
so if entry_id is 777 then the custom table fields are custom_777
my database has over 100 custom tables with specials fields for each record depending on its entry_id.
when i query the records I don't know how to join the custom fields that are entry_id specific to the rest of my data.i will pull up some tables and data for a better example
this is the list table:
this is the custom_"entry_id"
Full Outer Join in MySQL
for info on full outer joins.
Imagine an 1:N relationship among tables t_parent and t_child. The PK of the parent table t_parent is requestid and of course this is the FK for t_child. Also, t_child has another field called usermail which contains en email address. I want to write a SELECT statement which will return for every record of t_parent:
1)requestid (easy)
2)the number of records in t_child assosiated with the corresponding requestid (by using count, I am getting only one row as output even if the records of t_parent are more)
3)the emails from field usermail of the associated (with current requestid) records of t_child, all together combined in a string.
Is the above SELECT possible?
Thank you
SELECT t_parent.id, COUNT(*), GROUP_CONCAT(t_child.usermail)
FROM t_parent
LEFT JOIN t_child
ON t_parent.id = t_child.parent_id
GROUP BY t_parent.id
Suppose we have two tables, table A (parent) and table B (children) with a one to many relationship between them, established via parent_id (VARCHAR (100)) field in table B.
The parent_id field's datatype is different from id (INT(11)) field in table A. So the question is can MYSQL JOIN query return the proper records?
I encountered this kind of situation. I am running the following query:
SELECT p.payment_amount, s.company_name
FROM payments p
LEFT JOIN suppliers s ON p.supplier_id = s.id
LIMIT 5
Here one supplier has multiple payments. Now this query is returning me 5 records in which I can see the payment_amount for all 5 records but I can see company_name for only those records which have p.supplier_id one digit length. If in database I modify p.supplier_id to any valid 2 digit id, I cant get the supplier record.
MySQL can join with different data type, but the performance is poor as it has to convert from one type to the other for each row.
I set up a quick SQL fiddle to demonstrate it working, based on your SQL above:-
http://www.sqlfiddle.com/#!2/f7d02a/1
Note that a leading character in the number stored in a string will result in it being evaluated to 0.