I am studying searching part on the SQL but i am getting errors
What I did was...
first, I have a display type table
display_id |
1 | LED
2 | LCD
3 | PDP
Second, I make select query.
SELECT * FROM Product
WHERE
display_id =
CASE #display_type
WHEN 1 then 'LED'
WHEN 2 then 'LCD'
WHEN 3 then 'PDP'
END
if display id is 1 then i would like show the ' LED ' for the result of query.
however, I am getting error
Msg 245, Level 16, State 1, Procedure search_item, Line 18
Conversion failed when converting the varchar value 'LED' to data type int.
i tried to use convert but it is not working.
does anybody know the solution of this problem ??
You're mixing data types in the WHERE clause. display_id appears to be and integer and you're comparing it to 'LED', 'LCD' or 'PDP, depending on the result of the CASE statement.
You can convert #display_type to a string for display purposes by moving your Case Statement to the Select clause.
SELECT
CASE WHEN convert(int, #display_type) = 1 then 'LED'
WHEN convert(int, #display_type) = 2 then 'LCD'
WHEN convert(int, #display_type) = 3 then 'PDP'
END as DisplayType,
*
FROM
Product
If all you are after is a list of Products with a certain display type....
SELECT
*
FROM
products as P
inner join MyDisplayTable as DISP on DISP .display_id = P.display_id
WHERE
DISP.Display_Type = #display_type
Assumes the "name" column of your displays table is Display_Type
Assumes Product table has a display_id column (hopefully with a foreign-key to the display table's primary key
Why are you using Case when you have a table that you can join?
SELECT Product.*, DisplayType.Type
FROM Product INNER JOIN DisplayType ON Product.display_id=DisplayType.display_id
You didn't specify the name of the column that contains 'LED', 'LCD', 'PDP' so if it's different, you'll have to change that part.
SELECT
*,
CASE #display_type
WHEN 1 then 'LED'
WHEN 2 then 'LCD'
WHEN 3 then 'PDP'
END as myType
FROM
Product
WHERE
display_id = #display_type
Related
I've come across following T-SQL today:
select c from (select 1 union all select 1) as d(c)
that yields following result:
c
-----------
1
1
The part that got me confused was d(c)
While trying to understand what's going on I've modified T-SQL into:
select c, b from (select 1, 2 union all select 3, 4) m(c, b)
which yields following result:
c b
----------- -----------
1 2
3 4
It was clear that d & m are table reference while letters in brackets c & b are reference to columns.
I wasn't able to find relevant documentation on msdn, but curious if
You're aware of such syntax?
What would be useful use case scenario?
select c from (select 1 union all select 1) as d(c)
is the same as
select c from (select 1 as c union all select 1) as d
In the first query you did not name the column(s) in your subquery, but named them outside the subquery,
In the second query you name the column(s) inside the subquery
If you try it like this (without naming the column(s) in the subquery)
select c from (select 1 union all select 1) as d
You will get following error
No column name was specified for column 1 of 'd'
This is also in the Documentation
As for the usage, some like to write it the first method, some in the second, whatever you prefer. It's all the same
An observation: Using the table constructor values gives you no way of naming the columns, which makes it neccessary to use column naming after the table alias:
select * from
(values
(1,2) -- can't give a column name here
,(3,4)
) as tableName(column1,column2) -- gotta do it here
You've already had comments that point you to the documentation of how derived tables work, but not to answer you question regarding useful use cases for this functionality.
Personally I find this functionality to be useful whenever I want to create a set of addressable values that will be used extensively in your statement, or when I want to duplicate rows for whatever reason.
An example of addressable values would be a much more compelx version of the following, in which the calculated values in the v derived table can be used many times over via more sensible names, rather than repeated calculations that will be hard to follow:
select p.ProductName
,p.PackPricePlusVAT - v.PackCost as GrossRevenue
,etc
from dbo.Products as p
cross apply(values(p.UnitsPerPack * p.UnitCost
,p.UnitPrice * p.UnitsPerPack * 1.2
,etc
)
) as v(PackCost
,PackPricePlusVAT
,etc
)
and an example of being able to duplicate rows could be in creating an exception report for use in validating data, which will output one row for every DataError condition that the dbo.Product row satisfies:
select p.ProductName
,e.DataError
from dbo.Products as p
cross apply(values('Missing Units Per Pack'
,case when p.SoldInPacks = 1 and isnull(p.UnitsPerPack,0) < 1 then 1 end
)
,('Unusual Price'
,case when p.Price > (p.UnitsPerPack * p.UnitCost) * 2 then 1 end
)
,(etc)
) as e(DataError
,ErrorFlag
)
where e.ErrorFlag = 1
If you can understand what these two scripts are doing, you should find numerous examples of where being able to generate additional values or additional rows of data would be very helpful.
My test table looks like this:
# select * from a;
source | target | id
--------+--------+----
1 | 2 | 1
2 | 3 | 2
3 | 0 | 3
My query is this one:
SELECT *
FROM (
SELECT
CASE
WHEN id<>1
THEN source
ELSE 0
END
AS source,
CASE
WHEN id<>1
THEN target
ELSE 0
END
AS target
FROM a
) x;
The query seems a bit odd because the CASE expression with the same criteria is repeated for every column. I would like to simplify this and tried the following, but it doesn't work as expected.
SELECT *
FROM (
SELECT
CASE
WHEN id<>1
THEN (source, target)
ELSE (0, 0)
END
AS r
FROM a
) x;
It yields one column with a row value, but I would rather get the two original columns. Separating them with a (r).* or similar doesn't work, because the "record type has not been registered".
I found several questions here with solutions regarding functions returning RECORD values, but none regarding this example with a sub-select.
Actually, there is a quite long list of columns, so repeating the same CASE expression many times makes the whole query quite unreadable.
Since the real problem - as opposed to this simplified case - consists of several CASE expressions and several column groups, a solution with a UNION won't help, because the number of UNIONs would be large and make it unreadable as well as several CASEs.
My actual question is: How can I get the original columns from the row value?
This answers the original question.
If I understood your needs, you want 0 and 0 for source and target when id = 1:
SELECT
0 AS source,
0 AS target
FROM tablename
WHERE id = 1
UNION ALL
SELECT
source,
target
FROM tablename
WHERE id <> 1
Revised answer: You can make your query work (fixing the record type has not been registered issue) by creating a TYPE:
CREATE TYPE stpair AS (source int, target int);
And cast the composite value column to that type:
SELECT id, (cv).source, (cv).target
FROM (
SELECT id, CASE
WHEN id <> 1 THEN (source, target)::stpair
ELSE (0, 0)::stpair
END AS cv
FROM t
) AS x
Having said that, it should be far more convenient to use arrays:
SELECT id, av[1] AS source, av[2] AS target
FROM (
SELECT id, CASE
WHEN id <> 1 THEN ARRAY[source, target]
ELSE ARRAY[0, 0]
END AS av
FROM t
) AS x
Demo on db<>fiddle
Will this work for you?
select source,target,id from a where id <>1 union all select 0 as source,0 as target,id from a where id=1 order by id
I have used union all to included cases where multiple records may have ID=1
So I found these 2 articles but they don't quite answer my question...
Find max value and show corresponding value from different field in SQL server
Find max value and show corresponding value from different field in MS Access
I have a table like this...
ID Type Date
1 Initial 1/5/15
1 Periodic 3/5/15
2 Initial 2/5/15
3 Initial 1/10/15
3 Periodic 3/6/15
4
5 Initial 3/8/15
I need to get all of the ID numbers that are "Periodic" or NULL and corresponding date. So I want a to get query results that looks like this...
ID Type Date
1 Periodic 3/5/15
3 Periodic 3/6/15
4
I've tried
select id, type, date1
from Table1 as t
where type in (select type
from Table1 as t2
where ((t2.type) Is Null) or "" or ("periodic"));
But this doesn't work... From what I've read about NULL you can't compare null values...
Why in SQL NULL can't match with NULL?
So I tried
SELECT id, type, date1
FROM Table1 AS t
WHERE type in (select type
from Table1 as t2
where ((t.Type)<>"Initial"));
But this doesn't give me the ID of 4...
Any suggestions?
Unless I'm missing something, you just want:
select id, type, date1
from Table1 as t
where (t.type Is Null) or (t.type = "") or (t.type = "periodic");
The or applies to boolean expressions, not to values being compared.
What I am trying to do is this.
table OEINHDIH is history of orders. Orders can have many order type rows. so that order 12345 can have types INT, COR etc within it.
we need the orders which are INT but don't have a correction order against it (COR COE). But when i run this sql i get only 1 ihent#. Also this has to be run in Crystal report where the user will drive this according to dates from and to which is h.IHDOCD.
select h.IHDOCD, h.IHENT#, h.IHSFX#, h.IHINV#, a.ADINTA
from astdta.OEINHDIH h
join astdta.Adressad a
on h.ihent# = a.ADENT#
where h.IHORDT = 'INT'
AND h.IHVIAC not in ('PML','FCM')
AND ADSFX# = '000'
and h.ihent# in (
select cor.ihent#
from astdta.OEINHDIH cor
where cor.IHORDT not in ('COR','COE'))
EDITED
I do believe your table astdta.OEINHDIH can contain data like :
ihen# | IHORDT
1 | 'INT'
1 | 'COR'
2 | 'INT'
3 | 'INT'
3 | 'COE'
In terms of performance, you should use left join + content is null instead of subquery to exclude corrected orders
select h.IHDOCD, h.IHENT#, h.IHSFX#, h.IHINV#, a.ADINTA
from astdta.OEINHDIH h
left join astdta.OEINHDIH cor -- get orders corrected
on h.ihent# = cor.ihent#
and cor.IHORDT in ('COR','COE')
join astdta.Adressad a
on h.ihent# = a.ADENT#
where h.IHORDT = 'INT'
and cor.ihent# is null -- remove orders corrected
AND h.IHVIAC not in ('PML','FCM')
AND ADSFX# = '000'
If you are missing rows that means you join or your where are excluding to much row
Is h.ihent# = a.ADENT# correct ?
Is h.IHVIAC not in ('PML','FCM') correct ?
Is ADSFX# = '000' correct ?
If you need to check that h.IHDOCD is between date use :
AND h.IHDOCD BETWEEN start_date AND end_date
with start_date and end_date formatted to the correct type.
I have some lack of information, so if I'm missing something, give me more informations on :
What you need
What are your data tables
What are your tables structure
What is your expected result
This question already exists:
Closed 10 years ago.
Possible Duplicate:
SQL Select DISTINCT using CAST
Let me try this one more time... I'm not a sql guy so please bear with me as I try to explain this... I have a table called t_recordkeepingleg with three columns of data. Column1 is named LEGTRIPNUMBER that happens to be a string that starts with the letter Q followed by 4 numbers. I need to strip off the Q and convert the remaining 4 characters (numbers) to an integer. Everyone with me so far? Column2 of this table is named LEGDATE. Column3 is named LEGGROUP.
Here's the input scenario
LEGTRIPNUMBER LEGDATE LEGGROUP
Q1001 08/12/12 0001
Q1001 09/15/12 0002
Q1002 09/01/12 0001
Q1002 09/08/12 0003
Q1002 09/09/12 0002
As you can see the input table has rows where LEGTRIPNUMBER occurs more than once. I only want the first occurrence.
This is my current select statement - it works but returns all rows.
SELECT *,
CAST(
substring("t_RecordkeepingLeg"."LEGTRIPNUMBER",2,4) as INT
) as Num_Trip_Num
FROM "1669"."dbo"."t_RecordkeepingLeg" "t_RecordkeepingLeg"
Where left "t_RecordkeepingLeg"."LEGTRIPNUMBER",1) = 'Q'
I want to modify this so that it only selects ONE occurance of the Qnnnn. When the row gets selected I want to have LEGDATE and LEGGROUP available to me. How do I do this?
Thank you,
Can it be as simple as below? I've just added condiotion on leggroup being 0001
SELECT *,
CAST(substring("t_RecordkeepingLeg"."LEGTRIPNUMBER",2,4) as INT) as Num_Trip_Num
FROM "1669"."dbo"."t_RecordkeepingLeg" "t_RecordkeepingLeg"
Where left ("t_RecordkeepingLeg"."LEGTRIPNUMBER",1) = 'Q'
and "t_RecordkeepingLeg"."LEGGROUP"='0001'
If you have a unique primay key in your table you can do something like the below;
SELECT CAST(
substring("t_RecordkeepingLeg"."LEGTRIPNUMBER",2,4) as INT
) as Num_Trip_Num
FROM "1669"."dbo"."t_RecordkeepingLeg" "t_RecordkeepingLeg"
Where "t_RecordkeepingLeg"."ID" In(
Select Min("t_RecordkeepingLeg"."ID")
From "1669"."dbo"."t_RecordkeepingLeg" "t_RecordkeepingLeg"
Where left ("t_RecordkeepingLeg"."LEGTRIPNUMBER",1) = 'Q'
Group By "t_RecordkeepingLeg"."LEGTRIPNUMBER"
)
Which values of LEGDATE & LEGGROUP do you want for the distinct LEGTRIPNUMBER? there are multiple non-distinct possibilities and the concept of "first occurrence" is only valid with an explicit order.
To get the values where LEGDATE is the earliest for example;
select Num_Trip_Num, LEGDATE, LEGGROUP from (
select
cast(substring(t_RecordkeepingLeg.LEGTRIPNUMBER, 2, 4) as INT) as Num_Trip_Num,
row_number() over (partition by substring(t_RecordkeepingLeg.LEGTRIPNUMBER, 2, 4) order by t_RecordkeepingLeg.LEGDATE asc) as row,
t_RecordkeepingLeg.LEGDATE,
t_RecordkeepingLeg.LEGGROUP
from t_RecordkeepingLeg
where left (t_RecordkeepingLeg.LEGTRIPNUMBER, 1) = 'Q'
) T
where row = 1