Using SQL Server 2008, have three tables, table a, table b and table c.
All have an ID column, but for table a and b the ID column is an identity integer, for table c the ID column is a varchar type
Currently a stored procedure take a name param, following certain logic, insert to table a or table b, get the identity, prefix with 'A' or 'B' then insert to table c.
Problem is, table C ID column potentially have the duplicated values, i.e. if identity from table A is 2, there might already have 'A2','A3','A5' in the ID column for table C, how to write a T-SQL query to identify the next available value in table C then ensure to update table A/B accordingly?
[Update]
this is the current step,
1. depends on input parameter, insert to table A or table B
2. initialize seed value = ##Identity
3. calculate ID value to insert to table C by prefix 'A' or append 'B' with the seed value
4. look for record match in table C by ID value from step 3, if didn't find any record, insert it, else increase seed value by 1 then repeat step 3
The issue being at a certain value range, there could be a huge block of value exists in table C ID, i.e. A3000 to A500000 existed now in table C ID, the database query is extemely slow if follow the existing logic. Needs to figure out a logic to smartly get the minimum available number (without the prefix)
it is hard to describe, hope this make more sense, I truly appreciate any help on this Thanks in advance!
This should do the trick. Simple self extracting example will work in SSMS. I even made it out of order just in case. You would just change your table to be where #Data is and then change Identifier field to replace 'ID'.
declare #Data Table ( Id varchar(3) );
insert into #Data values ('A5'),('A2'),('B1'),('A3'),('B2'),('A4'),('A1'),('A6');
With a as
(
Select
ID
, cast(right(Id, len(Id)-1) as int) as Pos
, left(Id, 1) as TableFrom
from #Data
)
select
TableFrom
, max(Pos) + 1 as NextNumberUp
from a
group by TableFrom
EDIT: If you want to not worry about production data you could add this last part amending what I wrote:
Select
TableFrom
, max(Pos) as LastPos
into #Temp
from a
group by TableFrom
select TableFrom, LastPos + 1
from #Temp
Regardless if this was production environment you are going to have to hit part of it at some time to get data. If the datasets are not too large and just varchar(256) or less and only 5 million rows or less you could dump that entire column from tableC to a temp table. Honestly query performance versus imports change vastly from system to system.
Following your design there shouldn't be any duplicates in Table C considering that A and B are unique.
A | B | C
1 1 A1
2 2 A2
B1
B2
Related
For example, this is possible in Oracle. I wanted to know if snowflake has a similar concept.
CREATE TABLE Purchases
(
purchase_date calendar.date%type,
customer_nr customer.customer_nr%type,
purchase_amount numeric(10,2)
)
I'm afraid there's no way to do that right now. You can use system$typeof to check for a column type, but that can't be used in a create table statement.
The referenceability that you have in your example is not available. You can build a table by joining one or more tables and/or views together and build the column list with columns from any of the joins and any that you explicitly add to the list. The key is to join on 1 = 2 or FALSE
Example
CREATE OR REPLACE TEMP TABLE TMP_X
AS
SELECT A."name" AS NAME
,A."owner" AS OWNER
,B.STG_ARRAY
,NULL::NUMERIC(10,2) AS PURCHASE_AMOUNT
,NULL AS COMMENT
FROM TABLE_A A
JOIN TABLE_B B
ON 1 = 2
;
NAME - takes datatype from A."name" column
OWNER - takes datatype from A."owner" column
STG_ARRAY - takes datatype from B.STG_ARRAY column
PURCHASE_AMOUNT - takes the datatype explicitly specified NUMERIC(10,2)
COMMENT - no explicit datatype -- takes default datatype of VARCHAR(16777216)
I am trying to build a temp table with grouped data from multiple tables (in an SP), I am successful in building the data set however I have a requirement that each grouped row have a unique id. I know there are ways to generate unique ids for each row, However the problem I have is that I need the id for a given row to be the same on each run regardless of the number of rows returned.
Example:
1st run:
ID Column A Column B
1 apple 15
2 orange 10
3 grape 11
2nd run:
ID Column A Column B
3 grape 11
The reason I want this is because i am sending this data up to SOLR and when I do a delta I need to have the ID back for the same row as its trying to re-index
Any way I can do this?
Not sure if this will help, not entirely confident of your wider picture, but ...
As your new data is assembled, log each [column a] value in a table of your own.
Give that table an IDENTITY column to do the numbering for you.
Now you can join any new data sets to your lookup table and you'll have a persistent number for each column A.
You just need to ensure that each time you query new data, you add new values to the lookup table.
create table dbo.myRef(
idx int identity(1,1)
,[A] nvarchar(100)
)
General draft as below ...
--- just simulating some input data here
with cte as (
select 'apple' as [A], 15 as [B]
UNION
select 'orange' as [A], 10 as [B]
UNION
select 'banana' as [A], 4 as [B]
)
select * into #temp from cte;
-- Put any new values into the lookup table
-- and they will be assigned a new index number by the identity column
insert into dbo.myRef([A])
select distinct [A]
from #temp where [A] not in (select [A] from dbo.myRef)
-- now pull your original data for output, joining to the lookup table to get a ref number.
select T.*,R.idx
from #temp T
inner join
oer.myRef R
on T.[A] = R.[A]
Sorry for the late reply, i was stuck with something else, however i solved my own issue.
I built 2 temp tables one with all the data from the various tables (#master) and another temp table (#final) to house all the grouped data with an empty column for ID
Next i did a concat(column1, '-',column2,'-', column3) on 3 columns from the #master and updated the #final table based on the type
this helped me to get the same concat ids on each run
This is my table:
DocumentTypeId DocumentType UserId CreatedDtm
--------------------------------------------------------------------------
2d47e2f8-4 PDF 443f-4baa 2015-12-03 17:56:59.4170000
b4b-4803-a Images a99f-1fd 1997-02-11 22:16:51.7000000
600-0e32 XL e60e07a6b 2015-08-19 15:26:11.4730000
40f8ff9f Word 79b399715 1994-04-23 10:33:44.2300000
8230a07c email 750e-4c3d 2015-01-10 09:56:08.1700000
How can I shift the last entire row (DocumentType=email) on 3rd position,(before DocumentType=XL) without changing table values?
Without wishing to deny the truth of what others have said here, SQL Server does have CLUSTERED indices. For full details on these and the difference between a clustered table and a non-clustered one, please see here. In effect, a clustered table does have data written to disk in index order. However, due to subsequent insertions and deletions, you should never rely on any given record being in a fixed ordinal position.
To get your data showing email third and XL fourth, you simply need to order by CreatedDtm. Thus:
declare #test table
(
DocumentTypeID varchar(20),
DocumentType varchar(10),
UserID varchar(20),
CreatedDtm datetime
)
INSERT INTO #test VALUES
('2d47e2f8-4','PDF','443f-4baa','2015-12-03 17:56:59'),
('b4b-4803-a','Images','a99f-1fd','1997-02-11 22:16:51'),
('600-0e32','XL','e60e07a6b','2015-08-19 15:26:11'),
('40f8ff9f','Word','79b399715','1994-04-23 10:33:44'),
('8230a07c','email','750e-4c3d','2015-01-10 09:56:08')
SELECT * FROM #test order by CreatedDtm
This gives a result set of:
40f8ff9f Word 79b399715 1994-04-23 10:33:44.000
b4b-4803-a Images a99f-1fd 1997-02-11 22:16:51.000
8230a07c email 750e-4c3d 2015-01-10 09:56:08.000
600-0e32 XL e60e07a6b 2015-08-19 15:26:11.000
2d47e2f8-4 PDF 443f-4baa 2015-12-03 17:56:59.000
This maybe what you are looking for, but I cannot stress enough, that it only gives email 3rd and XL 4th in this particular case. If the dates were different, it would not be so. But perhaps, this was all that you needed?
I assumed that you need to sort by DocumentTypecolumn.
Joining with a temp table, which may contain virtually DocumenTypes with desired SortOrder, you can achieve the result you want.
declare #tbl table(
DocumentTypeID varchar(50),
DocumentType varchar(50)
)
insert into #tbl(DocumentTypeID, DocumentType)
values
('2d47e2f8-4','PDF'),
('b4b-4803-a','Images'),
('600-0e32','XL'),
('40f8ff9f','Word'),
('8230a07c','email')
;
--this will give you original output
select * from #tbl;
--this will output rows with new sort order
select t.* from #tbl t
inner join
(
select *
from
(values
('PDF',1, 1),
('Images',2, 2),
('XL',3, 4),
('Word',4, 5),
('email',5, 3) --here I put new sort order '3'
) as dt(TypeName, SortOrder, NewSortOrder)
) dt
on dt.TypeName = t.DocumentType
order by dt.NewSortOrder
The row positions don't really matter in SQL tables, since it's all unordered sets of data, but if you really want to switch the rows I'd suggest you send all your data to temp table e.g,
SELECT * FROM [tablename] INTO #temptable
then delete/truncate the data from that table (if it won't mess the other tables it's connected to) and use the temp table you made to insert into it as you like, since it'll have all the same fields with the same data from the original.
I need to know if there is any way to have a SEQUENCE or something like that, as we have in Oracle. The idea is to get one number and then use it as a key to save some records in a table. Each time we need to save data in that table, first we get the next number from the sequence and then we use the same to save some records. Is not an IDENTITY column.
For example:
[ID] [SEQUENCE ID] [Code] [Value]
1 1 A 232
2 1 B 454
3 1 C 565
Next time someone needs to add records, the next SEQUENCE ID should be 2, is there any way to do it? the sequence could be a guid for me as well.
As Guillelon points out, the best way to do this in SQL Server is with an identity column.
You can simply define a column as being identity. When a new row is inserted, the identity is automatically incremented.
The difference is that the identity is updated on every row, not just some rows. To be honest, think this is a much better approach. Your example suggests that you are storing both an entity and detail in the same table.
The SequenceId should be the primary identity key in another table. This value can then be used for insertion into this table.
This can be done using multiple ways, Following is what I can think of
Creating a trigger and there by computing the possible value
Adding a computed column along with a function that retrieves the next value of the sequence
Here is an article that presents various solutions
One possible way is to do something like this:
-- Example 1
DECLARE #Var INT
SET #Var = Select Max(ID) + 1 From tbl;
INSERT INTO tbl VALUES (#var,'Record 1')
INSERT INTO tbl VALUES (#var,'Record 2')
INSERT INTO tbl VALUES (#var,'Record 3')
-- Example 2
INSERT INTO #temp VALUES (1,2)
INSERT INTO #temp VALUES (1,2)
INSERT INTO ActualTable (col1, col2, sequence)
SELECT temp.*, (SELECT MAX(ID) + 1 FROM ActualTable)
FROM #temp temp
-- Example 3
DECLARE #var int
INSERT INTO ActualTable (col1, col2, sequence) OUTPUT #var = inserted.sequence VALUES (1, 2, (SELECT MAX(ID) + 1 FROM ActualTable))
The first two examples rely on batch updating. But based on your comment, I have added example 3 which is a single input initially. You can then use the sequence that was inserted to insert the rest of the records. If you have never used an output, please reply in comments and I will expand further.
I would isolate all of the above inside of a transactions.
If you were using SQL Server 2012, you could use the SEQUENCE operator as shown here.
Forgive me if syntax errors, don't have SSMS installed
I want to alter a table and add a column that is the sum of two other columns, and this column is auto computed when I add new data.
The syntax for a computed column specification is as follows:
column-name AS formula
If the column values are to be stored within the database, the PERSISTED keyword should be added to the syntax, as follows:
column-name AS formula PERSISTED
You didn't mention an example, but if you wanted to add the column "sumOfAAndB" to calculate the Sum of A and B, your syntax looks like
ALTER TABLE tblExample ADD sumOfAAndB AS A + B
Hope that helps.
Rather than adding this column to the table, I would recommend using a View to calculate the extra column, and read from that.
Here is a tutorial on how to create views here:
http://odetocode.com/Articles/299.aspx
Your view query would look something like:
SELECT
ColumnA, ColumnB, (ColumnA+ColumnB) as ColumnC
FROM
[TableName]
You can use a view, but you may want to use a PERSISTED computed value if you don't want to incur the cost of computing the value each time you access the view.
e.g.
CREATE TABLE T1 (
a INT,
b INT,
operator CHAR,
c AS CASE operator
WHEN '+' THEN a+b
WHEN '-' THEN a-b
ELSE a*b
END
PERSISTED
) ;
See the SQL docs assuming you're using SQL Server of course.
How to create computed column during creation of new table:
CREATE TABLE PRODUCT
(
WORKORDERID INT NULL,
ORDERQTY INT NULL,
[ORDERVOL] AS CAST
(
CASE WHEN ORDERQTY < 10 THEN 'SINGLE DIGIT' WHEN ORDERQTY >=10 AND ORDERQTY < 100 THEN 'DOUBLE DIGIT'
WHEN ORDERQTY >=100 AND ORDERQTY < 1000 THEN 'THREE DIGIT' ELSE 'SUPER LARGE' END AS NVARCHAR(100)
)
)
INSERT INTO PRODUCT VALUES (1,1),(2,-1),(3,11)
SELECT * FROM PRODUCT
UPDATE table_name SET total = mark1+mark2+mark3;
first think you can insert all the data into the table and then you can update the table like this form.
//i hop it's help to you