I have a dataset containing road names and road types. There are many missing road names and I would like to populate missing names with a simple string declaring road type followed by a Unique integer identifier as exemplified below.
Path1
Path2
Path...
I am trying to use the declare function, but something is not correct in my statement.
DECLARE #i int
SET #i=0
UPDATE KMS_VEJMIDT_BRUDT
SET VEJNAVN = "Sti"+Str(#i), #i=#i+1
WHERE (((KMS_VEJMIDT_BRUDT.VEJNAVN) Is Null) AND ((KMS_VEJMIDT_BRUDT.VEJMTYPE)="Sti"));
Edit: I misread the question slightly - I've added "Sti" as a prefix for the generated numbers, and started at 1
You may be able to do this in a 3 step process as described in this answer. I'm assuming that you have an ID primary key field in the KMS_VEJMIDT_BRUDT table.
Step 1:
Make a SELECT query named GENERATE_NEXT_NAVN using the following SQL:
SELECT C.ID, "Sti"&[RowNo] AS NEXT_VEJNAVN
FROM (SELECT A.ID,
A.VEJMTYPE,
(select count(*) from KMS_VEJMIDT_BRUDT as B where A.ID>=B.ID AND B.VEJNAVN Is Null and A.VEJMTYPE = "Sti" ) AS RowNo
FROM KMS_VEJMIDT_BRUDT AS A
WHERE A.VEJNAVN Is Null
and A.VEJMTYPE = "Sti"
) AS C;
Note the use of a Row Number workaround as described in this answer. I use this to generate an incrementing number starting from the highest NAVN present in the source table.
Step 2:
Copy the query output from Step 1 into a temporary table:
SELECT GENERATE_NEXT_NAVN.*
INTO NEXT_NAVN_TEMP
FROM GENERATE_NEXT_NAVN;
Step 3:
Update the source table using the values in the temp table:
UPDATE KMS_VEJMIDT_BRUDT
INNER JOIN NEXT_NAVN_TEMP
ON KMS_VEJMIDT_BRUDT.ID = NEXT_NAVN_TEMP.ID
SET KMS_VEJMIDT_BRUDT.VEJNAVN = [NEXT_NAVN_TEMP].[NEXT_VEJNAVN];
Related
We have a table that contains configuration data for our application, and a separate table that contains global configuration data for our platform. In this instance, each table has a set of two fields to coalesce, as one of the fields is a specific value and one field is more globally considered. But if neither field is set in the application table I need the global configuration data checked in a similar way. For example our application data references "questions" and a query to get the correct value will look like:
SELECT COALESCE(QuestionStyleDoc,StyleDoc) AS Style
FROM TABLE1
WHERE ID = 1000
So that for instance 1000 I retrieve the value for questions, but if not set specifically for questions I get the main value set for instance 1000. But if neither of these values are configured I have a global configuration I can check:
SELECT COALESCE(Table1StyleDoc,WebStyleDoc) AS Style
FROM TABLE2
WHERE [KEY] = 1
That contains a value to be considered for all unset Table1 applications, or if not set a truly global value. Basically, I need to return the first non-null value like
COALESCE(TABLE1.QuestionStyleDoc,TABLE1.StyleDoc,TABLE2.Table1StyleDoc,TABLE2.WebStyleDoc) AS Style
But so far, have not had any luck between attempts to join or union the data. The goal is to get this to happen in a single query to remove round trips to the database for the application.
I think that you might be after a FULL JOIN:
SELECT COALESCE(t1.QuestionStyleDoc, t1.StyleDoc, t2.Table1StyleDoc, t2.WebStyleDoc) style
FROM (
SELECT QuestionStyleDoc, StyleDoc
FROM TABLE1
WHERE ID = 1000
) t1
FULL JOIN (
SELECT Table1StyleDoc, WebStyleDoc
FROM TABLE2
WHERE [KEY] = 1
) t2 ON 1 = 1
I would suggest you to create a scalar user defined function to get the global style. I am passing key as parameter. As you are suggesting, Key will always be 1. But, I am adding this as parameter, if you need to call the UDF for different key.
CREATE FUNCTION dbo.GetGlobalStyle(#Key int)
RETURNS VARCHAR(50)
AS
-- Returns global style
BEGIN
DECLARE #ret VARCHAR(50);
SET #ret = (SELECT COALESCE(Table1StyleDoc,WebStyleDoc) AS Style
FROM TABLE2
WHERE [KEY] = #key)
RETURN #ret;
END;
Now, refer this UDF in your SELECT statement for every application, so don't need to repeat the code.
SELECT COALESCE(QuestionStyleDoc,StyleDoc, dbo.GetGlobalStyle(1)) AS Style
FROM TABLE1
WHERE ID = 1000
I would like to update rows with values chosen randomly from a set of possible values.
Ideally I would be able to provide this values at runtime, using JdbcTemplate from Java application.
Example:
In a table, column "name" can contain any name. The goal is to run through the table and change all names to equal to either "Bob" or "Alice".
I know that this can be done by creating a sql function. I tested it and it was fine but I wonder if it is possible to just use simple query?
This will not work, seems that the value is computed once, and applied to all rows:
UPDATE test.table
SET first_name =
(SELECT a.name
FROM
(SELECT a.name, RAND() idx
FROM (VALUES('Alice'), ('Bob')) AS a(name) ORDER BY idx FETCH FIRST 1 ROW ONLY) as a)
;
I tried using MERGE INTO, but it won't even run (possible_names is not found in SET query). I am yet to figure out why:
MERGE INTO test.table
USING
(SELECT
names.fname
FROM
(VALUES('Alice'), ('Bob'), ('Rob')) AS names(fname)) AS possible_names
ON ( test.table.first_name IS NOT NULL )
WHEN MATCHED THEN
UPDATE SET
-- select random name
first_name = (SELECT fname FROM possible_names ORDER BY idx FETCH FIRST 1 ROW ONLY)
;
EDIT: If possible, I would like to only focus on fields being updated and not depend on knowing primary keys and such.
Db2 seems to be optimizing away the subselect that returns your supposedly random name, materializing it only once, hence all rows in the target table receive the same value.
To force subselect execution for each row you need to somehow correlate it to the table being updated, for example:
UPDATE test.table
SET first_name =
(SELECT a.name
FROM (VALUES('Alice'), ('Bob')) AS a(name)
ORDER BY RAND(ASCII(SUBSTR(first_name, 1, 1)))
FETCH FIRST 1 ROW ONLY)
or may be even
UPDATE test.table
SET first_name =
(SELECT a.name
FROM (VALUES('Alice'), ('Bob')) AS a(name)
ORDER BY first_name, RAND()
FETCH FIRST 1 ROW ONLY)
Now that the result of subselect seems to depend on the value of the corresponding row in the target table, there's no choice but to execute it for each row.
If your table has a primary key, this would work. I've assumed the PK is column id.
UPDATE test.table t
SET first_name =
( SELECT name from
( SELECT *, ROW_NUMBER() OVER(PARTITION BY id ORDER BY R) AS RN FROM
( SELECT *, RAND() R
FROM test.table, TABLE(VALUES('Alice'), ('Bob')) AS d(name)
)
)
AS u
WHERE t.id = u.id and rn = 1
)
;
There might be a nicer/more efficient solution, but I'll leave that to others.
FYI I used the following DDL and data to test the above.
create table test.table(id int not null primary key, first_name varchar(32));
insert into test.table values (1,'Flo'),(2,'Fred'),(3,'Sue'),(4,'John'),(5,'Jim');
I am facing a problem and cant find any solution to this. I have a source table (T) where I get data from field. The data may contain duplicate records with time stamp. My objective is to take the field data and store it into a final table (F) having the same structure.
Before inserting I check whether key field exists or not in the F if yes I update the the record in F with the latest one from T. Other wise I Insert the record in F from T. This works fine as long as there is no duplicate record in T. In case T has two records of the same key with different time stamp. It always inserts both the record (In case the key is primary key the insert operation fails). I am using following code for the operation -
IF EXISTS(SELECT * FROM [Final_Table] F, TMP_Source T WHERE T.IKEy =F.IKEY)
begin
print 'Update'
UPDATE [Final_Table]
SET [FULLNAME] = T.FULLNAME
,[FATHERNAME] = T.FATHERNAME
,[MOTHERNAME] = T.MOTHERNAME
,[SPOUSENAME] = T.SPOUSENAME
from TMP_Source T
WHERE Final_Table.IKEy = T.IKEy
and [Final_Table].[RCRD_CRN_DATE] < T.RCRD_CRN_DATE
--Print 'Update'
end
else
begin
INSERT INTO [Final_Table]
([IKEy],[FTIN],[FULLNAME],[FATHERNAME],[MOTHERNAME],[SPOUSENAME]
)
Select IKEy,FTIN,FULLNAME,FATHERNAME,MOTHERNAME,SPOUSENAME
from TMP_Source
end
The problem comes when I my T table has entries like -
IKey RCRD_CRN_DATE ...
123 10-11-2013-12.20.30
123 10-11-2013-12.20.35
345 10-11-2013-01.10.10
All three are inserted in the F table.
Please help.
Remove all but the latest row as a first step (well, in a CTE) using ROW_NUMBER() before attempting to perform the insert:
;WITH UniqueRows AS (
SELECT IKey,RCRD_CRN_DATE,FULL_NAME,FATHER_NAME,MOTHER_NAME,SPOUSENAME,FTIN,
ROW_NUMBER() OVER (PARTITION BY IKey ORDER BY RCRD_CRN_DATE desc) as rn
FROM TMP_Source
)
MERGE INTO Final_Table t
USING (SELECT * FROM UniqueRows WHERE rn = 1) s
ON t.IKey = s.IKey
WHEN MATCHED THEN UPDATE
SET [FULLNAME] = s.FULLNAME
,[FATHERNAME] = s.FATHERNAME
,[MOTHERNAME] = s.MOTHERNAME
,[SPOUSENAME] = s.SPOUSENAME
WHEN NOT MATCHED THEN INSERT
([IKEy],[FTIN],[FULLNAME],[FATHERNAME],[MOTHERNAME],[SPOUSENAME]) VALUES
(s.IKEy,s.FTIN,s.FULLNAME,s.FATHERNAME,s.MOTHERNAME,s.SPOUSENAME);
(I may not have all the columns entirely correct, they seem to keep switching around in your question)
(As you may have noticed, I've also switched to using MERGE since it allows us to express everything as a single declarative statement rather than writing procedural code)
I have a small access database with some tables. I am trying the code in the sql design within access. I just want to randomly select a record within a table.
I created a simple table called StateAbbreviation. It has two columns: ID and Abbreviation. ID is just an autonumber and Abbreviation are different abbreviations for states.
I saw this thread here. So I tried
SELECT Abbreviation
FROM STATEABBREVIATION
ORDER BY RAND()
LIMIT 1;
I get the error Syntax error (missing operator) in query expresion RAND() LIMIT 1. So I tired RANDOM() instead of RAND(). Same error.
None of the others worked either. What am I doing wrong? Thanks.
Ypercude provided a link that led me to the right answer below:
SELECT TOP 1 ABBREVIATION
FROM STATEABBREVIATION
ORDER BY RND(ID);
Note that for RND(), I believe that it has to be an integer value/variable.
You need both a variable and a time seed to not get the same sequence(s) each time you open Access and run the query - and to use Access SQL in Access:
SELECT TOP 1 Abbreviation
FROM STATEABBREVIATION
ORDER BY Rnd(-Timer()*[ID]);
where ID is the primary key of the table.
Please try this, it is helpful to you
It is possible by using a stored procedure and function, which I created it's have a extra column which you could be create in your table FLAG name and column all field value should be 0 Then it works
create Procedure proc_randomprimarykeynumber
as
declare #Primarykeyid int
select top 1
#Primarykeyid = u.ID
from
StateAbbreviation u
left join
StateAbbreviation v on u.ID = v.ID + 1
where
v.flag = 1
if(#Primarykeyid is null )
begin
UPDATE StateAbbreviation
SET flag = 0
UPDATE StateAbbreviation
SET flag = 1
WHERE ID IN (SELECT TOP 1 ID
FROM dbo.StateAbbreviation)
END
ELSE
BEGIN
UPDATE StateAbbreviation
SET flag = 0
UPDATE StateAbbreviation
SET flag = 1
WHERE ID IN (#Primarykeyid)
END
SET #Primarykeyid = 1
SELECT TOP 1
ID, Abbreviation
FROM
StateAbbreviation
WHERE
flag = 1
It is made in stored procedure run this and get serial wise primary key
exec proc_randomprimarykeynumber
Thanks and regard
Try this:
SELECT TOP 1 *
FROM tbl_name
ORDER BY NEWID()
Of course this may have performance considerations for large tables.
I've a table 'tblRandomString' with following data:
ID ItemValue
1 *Test"
2 ?Test*
I've another table 'tblSearchCharReplacement' with following data
Original Replacement
* `star`
? `quest`
" `quot`
; `semi`
Now, I want to make a replacement in the ItemValues using these replacement.
I tried this:
Update T1
SET ItemValue = select REPLACE(ItemValue,[Original],[Replacement])
FROM dbo.tblRandomString T1
JOIN
dbo.tblSpecialCharReplacement T2
ON T2.Original IN ('"',';','*','?')
But it doesnt help me because only one replacement is done per update.
One solution is I've to use as a CTE to perform multiple replacements if they exist.
Is there a simpler way?
Sample data:
declare #RandomString table (ID int not null,ItemValue varchar(500) not null)
insert into #RandomString(ID,ItemValue) values
(1,'*Test"'),
(2,'?Test*')
declare #SearchCharReplacement table (Original varchar(500) not null,Replacement varchar(500) not null)
insert into #SearchCharReplacement(Original,Replacement) values
('*','`star`'),
('?','`quest`'),
('"','`quot`'),
(';','`semi`')
And the UPDATE:
;With Replacements as (
select
ID,ItemValue,0 as RepCount
from
#RandomString
union all
select
ID,SUBSTRING(REPLACE(ItemValue,Original,Replacement),1,500),rs.RepCount+1
from
Replacements rs
inner join
#SearchCharReplacement scr
on
CHARINDEX(scr.Original,rs.ItemValue) > 0
), FinalReplacements as (
select
ID,ItemValue,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY RepCount desc) as rn
from
Replacements
)
update rs
set ItemValue = fr.ItemValue
from
#RandomString rs
inner join
FinalReplacements fr
on
rs.ID = fr.ID and
rn = 1
Which produces:
select * from #RandomString
ID ItemValue
----------- -----------------------
1 `star`Test`quot`
2 `quest`Test`star`
What this does is it starts with the unaltered texts (the top select in Replacements), then it attempts to apply any valid replacements (the second select in Replacements). What it will do is to continue applying this second select, based on any results it produces, until no new rows are produced. This is called a Recursive Common Table Expression (CTE).
We then use a second CTE (a non-recursive one this time) FinalReplacements to number all of the rows produced by the first CTE, assigning lower row numbers to rows which were produced last. Logically, these are the rows which were the result of applying the last applicable transform, and so will no longer contain any of the original characters to be replaced. So we can use the row number 1 to perform the update back against the original table.
This query does do more work than strictly necessary - for small numbers of rows of replacement characters, it's not likely to be too inefficient. We could clear it up by defining a single order in which to apply the replacements.
Will skipping the join table and nesting REPLACE functions work?
Or do you need to actually get the data from the other table?
-- perform 4 replaces in a single update statement
UPDATE T1
SET ItemValue = REPLACE(
REPLACE(
REPLACE(
REPLACE(
ItemValue,'*','star')
ItemValue,'?','quest')
ItemValue,'"','quot')
ItemValue,';','semi')
Note: I'm not sure if you need to escape any of the characters you're replacing