I have a postgres table defined as below:
CREATE TABLE public.Table_1
(
id bigint NOT NULL GENERATED ALWAYS AS IDENTITY ( INCREMENT 1
START 1 MINVALUE 1 MAXVALUE 9223372036854775807 CACHE 1 )
)
Due to data migration, the id column is messed up and the value for id that is being generated on INSERT is not unique. Hence, I need to reset the id column as below
SELECT MAX(id) + 1 From Table_1;
ALTER TABLE Table_1 ALTER COLUMN id RESTART WITH 935074;
Right now I run the first query to get the Max(id) + 1 value and then I need to substitute it in the ALTER query.
Is there a way to store the result of SELECT and just use the variable inside ALTER statement?
Here is one way to do it:
select setval(pg_get_serial_sequence('Table_1', 'id'), coalesce(max(id),0) + 1, false)
from Table_1;
Rationale:
pg_get_serial_sequence() returns the name of the sequence for the given table and column
set_val() can be used to reset the sequence
this can be wrapped in a select that gives you the current maximum value of id in the table (or 1 if the table is empty)
Related
I have a historic table that won't be updated with new inserts, and a have a view that everyday will be update with new inserts. So I need to know if my SQL is correct.
This SQL needs to get all entries that inside in FATO_Proposta_Planilha table (Table 1)
and to add the entries not similar that are in the FATO_Proposta_View table (Table 2).
So, this SQL must have all entries from Table 1 more all entries from Table 2 that are not repeated in the Table 1. Can you give a opinion about this SQL, please?
SELECT vw.[DescPac] [PA]
,vw.[DescRegional] [Regional]
,vw.[DescSuperintendencia] [Superintendencia]
,vw.[NUM_CPF_CNPJ] [Documento_Numero]
,pla.[Nome] [Nome]
,pla.[Produto] [Produto]
,pla.[Modalidade] [Modalidade]
,vw.[NUM_CONTRATO_CREDITO] [Contrato]
,vw.[DESC_FINALIDADE_OPCRED] [Finalidade]
,vw.[DATA_OPERACAO] [Data_operacao]
,pla.[Data_mov_entrada] [Data_mov_entrada]
,vw.[DATA_VENC_OPCRED] [Data_vencimento]
,vw.[VALOR_CONTRATO_OPCRED] [Valor_contrato]
,pla.[Processo_Lecon] [Processo_Lecon]
,CASE WHEN ISNULL(pla.Origem, '') = ''
THEN 'Esteira Convencional'
ELSE pla.Origem
END [Origem]
FROM Proposta_View vw
LEFT JOIN FATO_Proposta_Planilha pla
ON vw.NUM_CONTRATO_CREDITO = pla.Contrato
UNION
SELECT [PA] [PA]
,[Regional] [Regional]
,[Superintendencia] [Superintendencia]
,[Documento_Numero] [Documento_Numero]
,[Nome] [Nome]
,[Produto] [Produto]
,[Modalidade] [Modalidade]
,[Contrato] [Contrato]
,[Finalidade] [Finalidade]
,[Data_operacao] [Data_operacao]
,[Data_mov_entrada] [Data_mov_entrada]
,[Data_vencimento] [Data_vencimento]
,[Valor_contrato] [Valor_contrato]
,[Processo_Lecon] [Processo_Lecon]
,CASE WHEN ISNULL(Origem, '') = ''
THEN 'Esteira Convencional'
ELSE Origem
END [Origem]
If you are only inserting rows through the view you can add an extra column with a DEFAULT value to distinguish the old rows from the new ones.
For example if you have a table t as:
create table t (a int primary key not null);
insert into t (a) values (123), (456);
You can add the extra column as:
alter table t add is_new int default 1;
update t set is_new = 0;
create view v as select a from t;
Then each insert through the view won't see that new column and will insert with value 1.
insert into v (a) values (789), (444);
Then it's easy to find the new rows:
select * from t where is_new = 1;
Result:
a is_new
---- ------
444 1
789 1
Se running example at db<>fiddle.
I'm new to firebird and I have verious issues. I want to insert various lines into a table selected from another table.
Here's the code:
/*CREATE GENERATOR POS; */
SET GENERATOR POS TO 1;
SET TERM ^;
create trigger BAS_pkassign
for MATERIAL
active before insert position 66
EXECUTE BLOCK
AS
declare posid bigint;
select gen_id(POS, 1)
from RDB$DATABASE
into :posid;
BEGIN
END
SET TERM ; ^
INSERT INTO MATERIAL ( /*ID */ LOCATION, POSID, ARTID, ARTIDCONT, QUANTITY )
SELECT 1000, ':posid', 309, BAS_ART.ID, 1
FROM BAS_ART
WHERE BAS_ART.ARTCATEGORY LIKE '%MyWord%'
The ID should autoincrement from 66 on. The posid should autoincrement from 1 on.
Actually it is not inserting anything.
I'm using Firebird Maestro and have just opened the SQL Script Editor (which doesnt throw any error message on executing the script).
Can anybody help me?
Thanks!
Additional information:
The trigger should autoincrement the column "ID" - but I dont know how exactly I can change it so it works.. The ':posid' throws an error using it :posid but like this theres no error (I guess its interpretated as a string). But how do I use it right?
I dont get errors when I execute it. The table structure is easy. I have 2 tables:
1.
Material (
ID (INTEGER),
Location (INTEGER),
POSID (INTEGER),
ARTID (INTEGER),
ARTIDCONT (INTEGER),
QUANTITY (INTEGER),
OTHERCOLUMN (INTEGER))
and the 2. other table
BAS_ART (ID (INTEGER), ARTCATEGORY (VARCHAR255))
-> I want to insert all entries from the table BAS_ART which contain "MyWord" in the column ARTCATEGORY into the MATERIAL table.
I don't understand why you need the trigger at all.
This problem:
I want to insert all entries from the table BAS_ART which contain "MyWord" into the MATERIAL table
Can be solved with a single insert ... select statement.
insert into material (id, location, posid, artid, quantity)
select next value for seq_mat_id, 1000, next value for seq_pos, id, 1
from bas_art
where artcategory = 'My Word';
This assumes that there is a second sequence (aka "generator") that is named seq_mat_id that provides the new id for the column material.id
For most of my answer I will assume a very simple table:
CREATE TABLE MyTable (
ID BIGINT PRIMARY KEY,
SomeValue VARCHAR(255),
posid INTEGER
)
Auto-increment identifier
Firebird (up to version 2.5) does not have an identity column type (this will be added in Firebird 3), instead you need to use a sequence (aka generator) and a trigger to get this.
Sequence
First you need to create a sequence using CREATE SEQUENCE:
CREATE SEQUENCE seqMyTable
A sequence is atomic which means interleaving transactions/connections will not get duplicate values, it is also outside transaction control, which means that a ROLLBACK will not revert to the previous value. In most uses a sequences should always increase, so the value reset you do at the start of your question is wrong for almost all purposes; for example another connection could reset the sequence as well midway in your execution leaving you with unintended duplicates of POSID.
Trigger
To generate a value for an auto-increment identifier, you need to use a BEFORE INSERT TRIGGER that assigns a generated value to the - in this example - ID column.
CREATE TRIGGER trgMyTableAutoIncrement FOR MyTable
ACTIVE BEFORE INSERT POSITION 0
AS
BEGIN
NEW.ID = NEXT VALUE FOR seqMyTable;
END
In this example I always assign a generated value, other examples assign a generated value only when the ID is NULL.
Getting the value
To get the generated value you can use the RETURNING-clause of the INSERT-statement:
INSERT INTO MyTable (SomeValue) VALUES ('abc') RETURNING ID
INSERT INTO ... SELECT
Using INSERT INTO ... SELECT you can select rows from one table and insert them into others. The reason it doesn't work for you is because you are trying to assign the string value ':pos' to a column of type INTEGER, and that is not allowed.
Assuming I have another table MyOtherTable with a similar structure as MyTable I can transfer values using:
INSERT INTO MyTable (SomeValue)
SELECT SomeOtherValue
FROM MyOtherTable
Using INSERT INTO ... SELECT it is not possible to obtain the generated values unless only a single row was inserted.
Guesswork with regard to POSID
It is not clear to me what POSID is supposed to be, and what values it should have. It looks like you want to have an increasing value starting at 1 for a single INSERT INTO ... SELECT. In versions of Firebird up to 2.5 that is not possible in this way (in Firebird 3 you would be able to use ROW_NUMBER() for this).
If my guess is right, then you will need to use an EXECUTE BLOCK (or a stored procedure) to assign and increase the value for every row to be inserted.
The execute block would be something like:
EXECUTE BLOCK
AS
DECLARE posid INTEGER = 1;
DECLARE someothervalue VARCHAR(255);
BEGIN
FOR SELECT SomeOtherValue FROM MyOtherTable INTO :someothervalue DO
BEGIN
INSERT INTO MyTable (SomeValue, posid) VALUES (:someothervalue, :posid);
posid = posid + 1;
END
END
Without an ORDER BY with the SELECT the value of posid is essentially meaningless, because there is no guaranteed order.
I create a table and sequence in order to replace identity in the table I use SQL Server 2012 Express but I get this error while I tried to insert data to the table
Msg 11719, Level 15, State 1, Line 2
NEXT VALUE FOR function is not allowed in check constraints, default objects, computed columns,
views, user-defined functions, user-defined aggregates, user-defined
table types, sub-queries, common table expressions, or derived
tables.
T-SQL code:
insert into Job_Update_Log(log_id, update_reason, jobid)
values((select next value for Job_Log_Update_SEQ),'grammer fixing',39);
This is my table:
create table Job_Update_Log
(
log_id int primary key ,
update_reason nvarchar(100) ,
update_date date default getdate(),
jobid bigint not null,
foreign key(jobid) references jobslist(jobid)
);
and this is my sequence:
CREATE SEQUENCE [dbo].[Job_Log_Update_SEQ]
AS [int]
START WITH 1
INCREMENT BY 1
NO CACHE
GO
Just get rid of the subselect in the VALUES section, like this:
insert into Job_Update_Log(log_id,update_reason,jobid)
values (next value for Job_Log_Update_SEQ,'grammer fixing',39);
Reference: http://msdn.microsoft.com/en-us/library/hh272694%28v=vs.103%29.aspx
Your insert syntax appears to be wrong. You are attempting to use a SELECT statement inside of the VALUES section of your query. If you want to use SELECT then you will use:
insert into Job_Update_Log(log_id,update_reason,jobid)
select next value for Job_Log_Update_SEQ,'grammer fixing',39;
See SQL Fiddle with Demo
I changed the syntax from INSERT INTO VALUES to INSERT INTO ... SELECT. I used this because you are selecting the next value of the sequence.
However, if you want to use the INSERT INTO.. VALUES, you will have to remove the SELECT from the query:
insert into Job_Update_Log(log_id,update_reason,jobid)
values(next value for Job_Log_Update_SEQ,'grammer fixing',39);
See SQL Fiddle with Demo
Both of these will INSERT the record into the table.
Try this one:
–With a table
create sequence idsequence
start with 1 increment by 3
create table Products_ext
(
id int,
Name varchar(50)
);
INSERT dbo.Products_ext (Id, Name)
VALUES (NEXT VALUE FOR dbo.idsequence, ‘ProductItem’);
select * from Products_ext;
/* If you run the above statement two types, you will get the following:-
1 ProductItem
4 ProductItem
*/
drop table Products_ext;
drop sequence idsequence;
------------------------------
Is there a way to combine assigning a value to a variable and Selecting a column in sql. I need to compute and select a column in a table based on the variable. The variable's value changes based on another column in the table.
var #BeginValue
Columns in table : ReducedBy
My initial begin value is stored in #BeginValue. The table has reducedBy which is a factor by which my begin value should be reduced. So when i select, beginvalue for the first recored would be #BeginValue and the #EndValue should be #BeginValue = #BeginValue - reducedBy. It continues like this, as many times as the number of records in my table.
Result set must be like this:
#Begin = 10
Begin End ReducedBy
10 8 2
8 6 2
6 5 1
Is there a way with which i can achieve this without using a cursor or with multiple update statements.
You can't assign in a query that returns a result set. The closest you can get is to store the result in a table variable. Then you can both do computations against that table, and return it as a result set:
-- Store results in table variable
declare #tbl table (id int, col1 int, ...)
insert #tbl
(id, col1, ...)
select id
, col1
, ...
from ... your query here ...
-- Assign variable
select #YourVariable = ... your computation here ...
from #tbl
-- Return result set
select *
from #tbl
If your question is
Can I do..
SELECT #a = field, field2 from table
and get a resultset and set the value of #a?
Then the answer is no, not in a single statement.
Suppose I had a set of alpha-character identifiers of a set length, e.g. always five letters, and they are assigned in such a way that they are always incremented sequentially (GGGGZ --> GGGHA, etc.). Now, if I get to ZZZZZ, since the length is fixed, I must "roll over" to AAAAA. I might have a contiguous block from ZZZAA through AAAAM. I want to write a sproc that will give me the "next" identifier, in this case AAAAN.
If I didn't have this "rolling over" issue, of course, I'd just ORDER BY DESC and grab the top result. But I'm at a bit of a loss now -- and it doesn't help at all that SQL is not my strongest language.
If I have to I can move this to my C# calling code, but a sproc would be a better fit.
ETA: I would like to avoid changing the schema (new column or new table); I'd rather just be able to "figure it out". I might even prefer to do it brute force (e.g. start at the lowest value and increment until I find a "hole"), even though that could get expensive. If you have an answer that does not modify the schema, it'd be a better solution for my needs.
Here's code that I think will give you your Next value. I created 3 functions. The table is just my simulation of the table.column with your alpha ids (I used MyTable.AlphaID). I assume that it's as you implied and there is one contiguous block of five-character uppercase alphabetic strings (AlphaID):
IF OBJECT_ID('dbo.MyTable','U') IS NOT NULL
DROP TABLE dbo.MyTable
GO
CREATE TABLE dbo.MyTable (AlphaID char(5) PRIMARY KEY)
GO
-- Play with different population scenarios for testing
INSERT dbo.MyTable VALUES ('ZZZZY')
INSERT dbo.MyTable VALUES ('ZZZZZ')
INSERT dbo.MyTable VALUES ('AAAAA')
INSERT dbo.MyTable VALUES ('AAAAB')
GO
IF OBJECT_ID('dbo.ConvertAlphaIDToInt','FN') IS NOT NULL
DROP FUNCTION dbo.ConvertAlphaIDToInt
GO
CREATE FUNCTION dbo.ConvertAlphaIDToInt (#AlphaID char(5))
RETURNS int
AS
BEGIN
RETURN 1+ ASCII(SUBSTRING(#AlphaID,5,1))-65
+ ((ASCII(SUBSTRING(#AlphaID,4,1))-65) * 26)
+ ((ASCII(SUBSTRING(#AlphaID,3,1))-65) * POWER(26,2))
+ ((ASCII(SUBSTRING(#AlphaID,2,1))-65) * POWER(26,3))
+ ((ASCII(SUBSTRING(#AlphaID,1,1))-65) * POWER(26,4))
END
GO
IF OBJECT_ID('dbo.ConvertIntToAlphaID','FN') IS NOT NULL
DROP FUNCTION dbo.ConvertIntToAlphaID
GO
CREATE FUNCTION dbo.ConvertIntToAlphaID (#ID int)
RETURNS char(5)
AS
BEGIN
RETURN CHAR((#ID-1) / POWER(26,4) + 65)
+ CHAR ((#ID-1) % POWER(26,4) / POWER(26,3) + 65)
+ CHAR ((#ID-1) % POWER(26,3) / POWER(26,2) + 65)
+ CHAR ((#ID-1) % POWER(26,2) / 26 + 65)
+ CHAR ((#ID-1) % 26 + 65)
END
GO
IF OBJECT_ID('dbo.GetNextAlphaID','FN') IS NOT NULL
DROP FUNCTION dbo.GetNextAlphaID
GO
CREATE FUNCTION dbo.GetNextAlphaID ()
RETURNS char(5)
AS
BEGIN
DECLARE #MaxID char(5), #ReturnVal char(5)
SELECT #MaxID = MAX(AlphaID) FROM dbo.MyTable
IF #MaxID < 'ZZZZZ'
RETURN dbo.ConvertIntToAlphaID(dbo.ConvertAlphaIDToInt(#MaxID)+1)
IF #MaxID IS NULL
RETURN 'AAAAA'
SELECT #MaxID = MAX(AlphaID)
FROM dbo.MyTable
WHERE AlphaID < dbo.ConvertIntToAlphaID((SELECT COUNT(*) FROM dbo.MyTable))
IF #MaxID IS NULL
RETURN 'AAAAA'
RETURN dbo.ConvertIntToAlphaID(dbo.ConvertAlphaIDToInt(#MaxID)+1)
END
GO
SELECT * FROM dbo.MyTable ORDER BY dbo.ConvertAlphaIDToInt(AlphaID)
GO
SELECT dbo.GetNextAlphaID () AS 'NextAlphaID'
By the way, if you don't want to assume contiguity, you can do as you suggested and (if there's a 'ZZZZZ' row) use the first gap in the sequence. Replace the last function with this:
IF OBJECT_ID('dbo.GetNextAlphaID_2','FN') IS NOT NULL
DROP FUNCTION dbo.GetNextAlphaID_2
GO
CREATE FUNCTION dbo.GetNextAlphaID_2 ()
RETURNS char(5)
AS
BEGIN
DECLARE #MaxID char(5), #ReturnVal char(5)
SELECT #MaxID = MAX(AlphaID) FROM dbo.MyTable
IF #MaxID < 'ZZZZZ'
RETURN dbo.ConvertIntToAlphaID(dbo.ConvertAlphaIDToInt(#MaxID)+1)
IF #MaxID IS NULL
RETURN 'AAAAA'
SELECT TOP 1 #MaxID=M1.AlphaID
FROM dbo.Mytable M1
WHERE NOT EXISTS (SELECT 1 FROM dbo.MyTable M2
WHERE AlphaID = dbo.ConvertIntToAlphaID(dbo.ConvertAlphaIDToInt(M1.AlphaID) + 1 )
)
ORDER BY M1.AlphaID
IF #MaxID IS NULL
RETURN 'AAAAA'
RETURN dbo.ConvertIntToAlphaID(dbo.ConvertAlphaIDToInt(#MaxID)+1)
END
GO
You'd have to store the last allocated identifier in the sequence.
For example, store it in another table that has one column & one row.
CREATE TABLE CurrentMaxId (
Id CHAR(6) NOT NULL
);
INSERT INTO CurrentMaxId (Id) VALUES ('AAAAAA');
Each time you allocate a new identifier, you'd fetch the value in that tiny table, increment it, and store that value in your main table as well as updating the value in CurrentMaxId.
The usual caveats apply with respect to concurrency, table-locking, etc.
I think I'd have tried to store the sequence as an integer, then translate it to string. Or else store a parallel integer column that is incremented at the same time as the alpha value. Either way, you could sort on the integer column.
A problem here is that you can't really tell from the data where the "last" entry is unless there is more detail as to how the old entries are deleted.
If I understand correctly, you are wrapping around at the end of the sequence, which means you must be deleting some of your old data to make space. However if the data isn't deleted in a perfectly uniform manner, you'll end up with fragments, like below:
ABCD HIJKL NOPQRS WXYZ
You'll notice that there is no obvious next value...D could be the last value created, but it might also be L or S.
At best you could look for the first or last missing element (use a stored procedure to perform a x+1 check just like you would to find a missing element in an integer sequence), but it's not going to provide any special result for rolled-over lists.
Since I don't feel like writing code to increment letters, I'd create a table of all valid IDs (AAAAAA through ZZZZZZ) with an integer from 1 to X for those IDs. Then you can use the following:
SELECT #max_id = MAX(id) FROM Possible_Silly_IDs
SELECT
COALESCE(MAX(PSI2.silly_id), 'AAAAAA')
FROM
My_Table T1
INNER JOIN Possible_Silly_IDs PSI1 ON
PSI1.silly_id = T1.silly_id
INNER JOIN Possible_Silly_IDs PSI2 ON
PSI2.id = CASE WHEN PSI1.id = #max_id THEN 1 ELSE PSI1.id + 1 END
LEFT OUTER JOIN My_Table T2 ON
T2.silly_id = PSI2.silly_id
WHERE
T2.silly_id IS NULL
The COALESCE is there in case the table is empty. To be truly robust you should calculate the 'AAAAAA' (SELECT #min_silly_id = silly_id WHERE id = 1) in case your "numbering" algorithm changes.
If you really wanted to do things right, you'd redo the database design as has been suggested.
I think the lowest-impact solution for my needs is to add an identity column. The one thing I can guarantee is that the ordering will be such that entries that should "come first" will be added first -- I'll never add one with identifier BBBB, then go back and add BBBA later. If I didn't have that constraint, obviously it wouldn't work, but as it stands, I can just order by the identity column and get the sort I want.
I'll keep thinking about the other suggestions -- maybe if they "click" in my head, they'll look like a better option.
To return the next ID for a given ID (with rollover), use:
SELECT COALESCE
(
(
SELECT TOP 1 id
FROM mytable
WHERE id > #id
ORDER BY
id
),
(
SELECT TOP 1 id
FROM mytable
ORDER BY
id
)
) AS nextid
This query searches for the ID next to the given. If there is no such ID, it returns the first ID.
Here are the results:
WITH mytable AS
(
SELECT 'AAA' AS id
UNION ALL
SELECT 'BBB' AS id
UNION ALL
SELECT 'CCC' AS id
UNION ALL
SELECT 'DDD' AS id
UNION ALL
SELECT 'EEE' AS id
)
SELECT mo.id,
COALESCE
(
(
SELECT TOP 1 id
FROM mytable mi
WHERE mi.id > mo.id
ORDER BY
id
),
(
SELECT TOP 1 id
FROM mytable mi
ORDER BY
id
)
) AS nextid
FROM mytable mo
id nextid
----- ------
AAA BBB
BBB CCC
CCC DDD
DDD EEE
EEE AAA
, i. e. it returns BBB for AAA, CCC for BBB, etc., and, finally, AAA for EEE which is last in the table.