SQL - JOINING to table with a key that requires parsing - sql

I am new to SQL Server. I was trying to do query on a table which contains user list with location filter (multiple location). Below is the table.
User data table:
firstname lastname LocFilter
-----------------------------------------------------------
Riswan Parambath Lo_ID=251
Reda Dridi Lo_ID=733 or Lo_ID=758 or Lo_ID=783
Location table:
LocID LocationName
-----------------------
251 Qatar
733 Turkmenistan
758 Brunei
773 Iraq North
783 Iraq South
Now I am trying to query the table using inner join to get the country name using below code
SELECT
SecUsers.firstname,
Location.LocationName
FROM
SecUsers
INNER JOIN
Location on SecUsers.LocFilter = Location.LocID
But I am getting the error:
Msg 245, Level 16, State 1, Line 1
Conversion failed when converting the nvarchar value 'Lo_ID=962' to data type int.
It will be great if someone can help to fix this issue.

SQL doesn't work like that. You don't want to store conditions as strings.
Instead, you want two separate tables:
Users:
UserId FirstName LastName
1 Riswan Parambath
2 Reda Dridi
UserLocations:
UserLocationId UserId LocationId
1 1 251
2 2 733
3 2 758
4 2 783
The latter table is called a junction table (or sometimes an association table). Your queries will be much faster and easier to construct.

Having three rules in single cell violates normal form. From your thread, I could see this as table that already exists. So, I am providing following solution that can solve your exception. But, you have to change your table design for scalable solution.
select Distinct
Users.firstname,
Location.LocationName
from
SecUsers
inner join
Location on SecUsers.LocFilter like ('%Lo_ID=' + CAST(Location.LocID as VARCHAR(5)) + '%')

Related

Using TOP 1 (or CROSS APPLY) within multiple joins

I've reviewed multiple Q&A involving TOP 1 and CROSS APPLY (including the very informative 2043259), but I still can't figure out how to solve my issue. If I had a single join I'd be fine, but fitting TOP 1 into the middle of a chain of joins has stumped me.
I have four tables and one of the tables contains multiple matches when joining due to a previous bug (since fixed) that created new records in the table instead of updating existing records. In all cases, where there are multiple records, it is the top-most record that I want to use in one of my joins. I don't have access to the table to clean up the extraneous data, so I just have to deal with it.
The purpose of my query is to return a list of all "Buildings" managed by a particular person (user choses a person's name and they get back a list of all buildings managed by that person). My tables are:
Building (a list of all buildings):
BuildingId BuildingName
1 Oak Tree Lane
2 Lighthoue Court
3 Fairview Lane
4 Starview Heights
WebBuildingMapping (mapping of BuidingId from Building table, that is part of an old system, and corresponding WebBuildingId in another piece of software):
BuildingId WebBuildingId
1 201
2 202
3 203
4 204
WebBuildingContacts (list of ContactID for the building manager of each building). This is the table with duplicate values - where I want to choose the TOP 1. In sample data below, there are two references to WebBuidingId = 203 (row 3 & row 5) - I only want to use row 3 data in my join.
Id WebBuildingId ContactId
1 201 1301
2 202 1301
3 203 1303
4 204 1302
5 203 1302
Contacts (list of ContactIds and corresponding property manager Names)
ContactId FullName
1301 John
1302 Mike
1303 Judy
As noted, in the example above, the table WebBuildingContact has two entries for the building with a WebBuidingId = 203 (row 3 and row 5). In my query, I want to select the top one (row 3).
My original query for a list of buildings managed by 'Mike' is:
SELECT BuildingName
FROM Building bu
JOIN WebBuildingMapping wbm ON wbm.BuildingId = bu.BuildingId
JOIN WebBuildingContact wbc ON wbc.WebBuildingId = wbm.WebBuildingId
JOIN Contacts co ON co.ContactId = wbc.ContactId
WHERE co.FullName = 'Mike'
This returns 'Fairview Lane' and 'Starview Heights'; however, Judy manages 'Fairview Lane' (she's the top entry in the WebBuildingContacts table). To modify the query and eliminate row 5 in WebBuildingContacts from the join, I did the following:
SELECT BuildingName
FROM Building bu
JOIN WebBuildingMapping wbm ON wbm.BuildingId = bu.BuildingId
JOIN WebBuildingContact wbc ON wbc.WebBuildingId =
(
SELECT TOP 1 WebBuildingId
FROM WebBuildingContact
WHERE WebBuildingContact.WebBuildingId = wbm.WebBuildingId
)
JOIN Contacts co ON co.ContactId = wbc.ContactId
WHERE co.FullName = 'Mike'
When I try this; however, I get the same result set (ie it returns 'Mike' as manager for 2 buildings). I've also made various attempts to use CROSS APPLY but I just end up with 'The multi-part identifier could not be bound', which is a whole other rabbit hole to go down.
You could try this:
SELECT bu2.BuildingName
FROM building bu2
WHERE bu2.BuildingId IN
(SELECT MAX(bu.BuildingId)
FROM Building bu
JOIN WebBuildingMapping wbm ON wbm.BuildingId = bu.BuildingId
JOIN WebBuildingContact wbc ON wbc.WebBuildingId = wbm.WebBuildingId
JOIN Contacts co ON co.ContactId = wbc.ContactId
WHERE co.FullName = 'Mike'
);

PostGIS Intersect to update a field based on intersected State

I'll admit I'm a little out of my element with PostGIS and spatial geometries in a DB but here's what I'm after: I need to update a field with the determined intersected US State of a geom of an object if it doesn't yet already have one.
The DB structure is as follows:
Accomplishment
id
name
phys_state
poly_point_line_id (fk Accomplishment_Feature)
1
Test Accomp 1
AK
123
2
Test Accomp 2
456
3
Test Accomp 3
789
Accomplishment_Feature (technically not needed in the query AFAIK but included here just in case since it is a join table between the Accomplishment and its geometry types)
id
123
456
789
Accoomplishment_Poly
id (fk to Accomplishment_Feature)
geom
123
[multipolygon geometry]
Accoomplishment_Line
id (fk to Accomplishment_Feature)
geom
123
[multiline geometry]
Accoomplishment_Point
id (fk to Accomplishment_Feature)
geom
123
[multipoint geometry]
I need to determine the intersected US state of each of the geoms for Accomplishments that don't have a value in the physical_state column.
I currently have a table of US State geometries in another schema that I can use.
I currently have the following but it errors out and I'm obviously misunderstanding how to write the queries.
UPDATE accomplishment a
SET a.phys_state = us_state.abbrev
FROM support_gis.state_g us_state
LEFT JOIN accomplishment_poly poly on a.poly_point_line_id = poly.id
WHERE st_intersects(st_centroid(poly.geom), us_state.geom) AND a.phys_state is null
Any guidance or assistance would be greatly appreciated!
How the FROM clause in an UPDATE statement works is slightly different than in a SELECT - go figure. An alternative is to go old school: just put all involved tables in the FROM clause and solve the joins in the WHERE clause instead using JOINs.
UPDATE accomplishment
SET phys_state = us_state.abbrev
FROM support_gis.state_g us_state, accomplishment_poly poly
WHERE
ST_Intersects(ST_Centroid(poly.geom), us_state.geom) AND
phys_state IS NULL AND
poly_point_line_id = poly.id;

Run a set number of joined select statements under a single sql query

I have a counselling appointment website. Currently I list clients in one table, but also have couples listed by id in a second table for when they book a couples session. ie:
client
id_no first last
564 John Smith
983 Mary Jones
999 Mark Fields
882 Joan Hancock
couple
id_no client1 client2
623 564 983
555 999 882
I would like to write a single select statement, using aliases, which will list out couples on a single line. Up until now, I have been doing a simple join then cleaning up the result using php after running the query, but would like to clean this up in sql so that I get a result like the following
id_no first_1 last_1 first_2 last_2
623 John Smith Mary Jones
555 Mark Fields Joan Hancock
I suspect that sub queries might be involved, but can't for the life of me wrangle them to get this result.
Update
I just tried the following:
SELECT id_no,first_1,last_1,first_2,last_2
FROM ( SELECT a.id_no AS id_no, b.first AS first_1,b.last AS last_1
FROM couple AS a, client AS b WHERE a.client1=b.id_no ) c1
JOIN ( SELECT a.id_no AS id_no, b.first AS first_2,b.last AS last_2
FROM couple AS a, client AS b WHERE a.client2=b.id_no ) c2 ON
(c1.id_no=c2.id_no)
And am getting a message that "Column 'id_no' in field list is ambiguous". Not sure if I am on the right track
You are getting the exception because you did not specified the table alias to id_no as this column belongs to both tables, so SQL is not sure which column to return, so it will throw ambiguous column error.
Also you don't have to use sub queries, you just need to join client table twice with couple table, one for client1 and other one for client2 like below
Select cp.id_no,
cl1.first as first_1,
cl1.last as last_1,
cl2.first as first_2,
cl2.last as last_2
From couple cp
inner join client cl1 on cl1.id_no = cp.client1
inner join client cl2 on cl2.id_no = cp.client2

Select items where count in another field matches (not updatable)

Here I am trying to get the record for my products where the # swab location in Main table matches the count of swab locations in swab Table and Users can checked off the Y/N to verify that the description of the locations are correct.
Here is the example of my 2 tables.
tblMainEquipment
Asset_ID EquipmentName Num_SwapLocations Verified
234 Saijimon 2 N
235 Pasquale 3 N
tblMainSwapLocations
Asset_ID Swap_location
234 Particle Cannon
234 RailGun
235 Particle Cannon
I use the following query to count the number of records, i avoided using a having query to combine both tables since it is not updatable.
qryMainSwapLocationCount
SELECT MSL.Asset_ID, Count(Asset_ID) AS [Count]
FROM tblMainSwapLocation AS MSL
GROUP BY MSL.Asset_ID;
This will give me the result of
qryMainSwapLocationCount
Asset_ID count
234 2
234 1
I used the following as a record source for my form to allow users to verify the inputs.
SELECT MEQ.Asset_ID, MEQ.Equipment_Name,MEQ.Num_swapLocations MEQ.Verified
FROM tblMainEquipment AS MEQ, qryMainSwapLocationCount AS MSLC
WHERE (((MEQ.Asset_ID)=[MSLC].[Asset_ID]) AND ((MEQ.Num_SwapLocations)=[MSLC].[Count]);
This result would be
tblMainEquipment
Asset_ID EquipmentName Num_SwapLocations Verified
234 Saijimon 2 N
However this record set is not editable. Is there any reasons for this?
I think you should put your table tblMainEquipment as your recordsource and bring all the fields from that on to your form:
Then insert an unbound textbox (perhaps close to your Num_SwapLocations field for easy comparison):
Then in this new textbox, put the following in the ControlSource:
=DCount("ASSET_ID","tblMainSwapLocations","ASSET_ID=" & [Asset_ID])
Then open your form and it should count the number of records in table tblMainSwapLocations that have the same Asset_ID as the record currently showing:
You'll then be able to update the Verified field in your tblMainEquipment table.

Table Join issue

Right now I've got a Main table in which I am uploading data. Because the Main table has many different duplicates, I Append various data out of the Main table into other tables such as, username, phone number, and locations in order to keep things optimized. Once I have everything stripped down from the Main table, I then append what's left into a final optimized Main table. Before this happens though, I run a select query joining all the stripped tables with the original Main table in order to connect the IDs from each table, with the correct data. For example:
Original Main Table
--Name---------Number------Due Date-------Location-------Charges Monthly-----Charges Total--
John Smith 111-1111 4/3 Chicago 234.56 500.23
Todd Jones 222-2222 4/3 New York 174.34 323.56
John Smith 111-1111 4/3 Chicago 274.56 670.23
Bill James 333-3333 4/3 Orlando 100.00 100.00
This gets split into 3 tables (name, number, location) and then there is a date table with all the dates for the year:
Name Table Number Table Location Table Due Date Table
--ID---Name------ -ID--Number--------- ---ID---Location---- --Date---
1 John Smith 1 111-1111 1 Chicago 4/1
2 Todd Jones 2 222-2222 2 New York 4/2
3 Bill James 3 333-3333 3 Orlando 4/3
Before The Original table gets stripped, I run a select query that grabs the ID from the 3 new tables, and joins them based on the connection they have with the original Main table.
Select Output
--Name ID----Number ID---Location ID---Due Date--
1 1 1 4/3
2 2 2 4/3
1 1 1 4/3
3 3 3 4/3
My issue comes when I need to introduce a new table that isn't able to be tied into the Original Main Table. I have an inventory table that, much like the original Main table, has duplicates and needs to be optimized. I do this by creating a secondary table that takes all the duplicated devices out and put them in their own table, and then strips the username and number out and puts them into their tables. I would like to add the IDs from this new device table into the select output that I have above. Resulting in:
Select Output
--Name ID----Number ID---Location ID---Due Date--Device ID---
1 1 1 4/3 1
2 2 2 4/3 1
1 1 1 4/3 2
3 3 3 4/3 1
Unlike the previous tables, the device table has no relationship to the originalMain Table, which is what is causing me so much headache. I can't seem to find a way to make this happen...is there anyway to accomplish this?
Any two tables can be joined. A table represents an application relationship. In some versions (not the original) of Entity-Relationship Modelling (notice that the "R" in E-R stands for "(application) relationship"!) a foreign key is sometimes called a "relationship". You do not need other tables or FKs to join any two tables.
Explain, in terms of its column names and the values for those names, exactly when a row should turn up in the result. Maybe you want:
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
USING NameID, NumberID, LocationID and DueDate
Ie
SELECT *
FROM the stripped-and-ID'd version of the Original AS o
JOIN the stripped-and-ID'd version of the Device AS d
ON o.NameID=d.NameId AND o.NumberID=d.NumberID
AND o.LocationID=d.LocationID AND o.DueDateID=d.DueDate.
Suppose p(a,...) is some statement parameterized by a,... .
If o holds the rows where o(NameID,NumberID,LocationID,DueDate) and d holds the rows where d(NameID,NumberID,LocationID,DueDate,DeviceID) then the above holds the rows where o(NameID, NumberID, LocationID, DueDate) AND d(NameID,NumberID,LocationID,DueDate,DeviceID). But you really have not explained what rows you want.
The only way to "join" tables that have no relation is by unioning them together:
select attribute1, attribute2, ... , attributeN
from table1
where <predicate>
union // or union all
select attribute1, attribute2, ... , attributeN
from table2
where <predicate>
the where clauses are obviously optional
EDIT
optionally you could join the tables together by stating ON true which will act like a cross product