I'm trying to create my own logic for tables synchronization in SQL Server Express 2019. I was hoping that such simple task would work:
Have a Customers table
Have a Synchronization table
CREATE TABLE [dbo].[Synchronization]
(
[PK] [uniqueidentifier] NOT NULL,
[TableName] [nchar](50) NOT NULL,
[RecordPK] [uniqueidentifier] NOT NULL,
[RecordChecksum] [int] NOT NULL,
[RecordDate] [datetime] NOT NULL,
[RecordIsDeleted] [bit] NOT NULL
)
Have a trigger on Customers:
CREATE TRIGGER trgCustomers_INSERT
ON Customers
AFTER INSERT
AS
INSERT INTO Synchronization(PK, TableName, RecordPK, RecordChecksum,
RecordDate, RecordIsDeleted)
VALUES (NEWID(), 'Customers',
(SELECT PK FROM inserted),
(SELECT CHECKSUM(*) FROM inserted),
GETDATE(), 0)
... but I got an error about the SELECT CHECKSUM(*) FROM inserted part:
Cannot use CHECKSUM(*) in a computed column, constraint, default definition, or INSERT statement.
Is there any other way to add new Customer's CHECKSUM or some hash to the Synchronization table?
Don't use the VALUES syntax when inserting and you won't get an error using CHECKSUM while inserting.
Example:
declare #t table (val int)
-- works
insert into #t select checksum(*) from ( select ID from (select 1 as ID union select 2) b ) a
-- reproduce error
insert into #t
values
((select top 1 checksum(*) C from ( select ID from (select 1 as ID union select 2) b ) a))
Implementing the concept in your trigger:
CREATE TRIGGER trgCustomers_INSERT
ON Customers
AFTER INSERT
AS
begin
INSERT INTO Synchronization(PK, TableName, RecordPK, RecordChecksum,
RecordDate, RecordIsDeleted)
select NEWID() as PK,
'Customers' as TableName,
PK as RecordPK,
checksum(*) as RecordChecksum,
GETDATE() as RecordDate,
0 as RecordIsDeleted
from inserted
end
Related
let say,
insert into A select * from A where col1 = "ABC"
leads to an error as there would be the same primary key column, I want to increment automatically from the max id the table have
CREATE TABLE A(
[WFID] [int] NOT NULL PRIMARY KEY,
[EntityID1] [int] NOT NULL,
[EntityID2] [int] NULL);
INSERT INTO WFCustom
SELECT * FROM WFCustom
WHERE EntityID2 = 6008 ,
getting an error as WFID is a primary key :
Violation of PRIMARY KEY constraint 'PK_WF_Custom'. Cannot insert duplicate key in object 'dbo.WFCustom'.
The statement has been terminated.
You can try following query using ROW_NUMBER()
INSERT INTO wfcustom
SELECT (SELECT Max(wfid)
FROM WFCustom) + (Row_number() OVER(ORDER BY (SELECT 1))) AS id,
entityid1,
entityid2
FROM wfcustom
Online Demo
Note:
As suggested by #DanGuzman, insert can fail in scenarios when same query is running from multiple sessions under read committed isolation level. So it's always advisable to use Identity column for this type of scenarios.
My first suggestion is to fix your data model. This would look like:
CREATE TABLE A (
[WFID] int IDENTITY(1, 1) PRIMARY KEY,
[EntityID1] [int] NOT NULL,
[EntityID2] [int] NULL
);
INSERT INTO WFCustom (EntityID1, EntityID2)
SELECT EntityID1, EntityID2
FROM WFCustom
WHERE EntityID2 = 6008;
This is the safest method for being sure that primary keys are unique -- the database takes care of it.
If that doesn't work, you can assign a new one. The method proposed by PSK is fine, although I would write it as:
INSERT INTO WFCustom (WFID, EntityID1, EntityID2)
SELECT (COALESCE(MAX_WFID, 0) +
ROW_NUMBER() OVER (ORDER BY WFID)
) as new_WFID,
EntityID1, EntityID2
FROM WFCustom CROSS JOIN
(SELECT MAX(WFID) as MAX_WFID FROM WFCustom) m
WHERE EntityID2 = 6008;
I'm trying the following
Insert number of records to table A with a table-valued parameter (tvp). This tvp has extra column(s) that are not in A
Get the inserted ids from A and the corresponding extra columns in the the tvp and add them to another table B
Here's what I tried
Type:
CREATE TYPE tvp AS TABLE
(
id int,
otherid int,
name nvarchar(50),
age int
);
Tables:
CREATE TABLE A (
[id_A] [int] IDENTITY(1,1) NOT NULL,
[name] [varchar](50),
[age] [int]
);
CREATE TABLE B (
[id_B] [int] IDENTITY(1,1) NOT NULL,
[id_A] [int],
[otherid] [int]
);
Insert:
DECLARE #a1 AS tvp;
DECLARE #a2 AS tvp
-- create a tvp (dummy data here - will be passed to as a param to an SP)
INSERT INTO #a1 (name, age, otherid) VALUES ('yy', 10, 99999), ('bb', 20, 88888);
INSERT INTO A (name, age)
OUTPUT
inserted.id_A,
inserted.name,
inserted.age,
a.otherid -- <== isn't accepted here
INTO #a2 (id, name, age, otherid)
SELECT name, age FROM #a1 a;
INSERT INTO B (id_A, otherid) SELECT id, otherid FROM #a2
However, this fails with The multi-part identifier "a.otherid" could not be bound., which I guess is expected because columns from other tables are not accepted for INSERT statement (https://msdn.microsoft.com/en-au/library/ms177564.aspx).
from_table_name
Is a column prefix that specifies a table included in the FROM clause of a DELETE, UPDATE, or MERGE statement that is used to specify the rows to update or delete.
So is there any other way to achieve this?
You cannot select value from a source table by using INTO operator.
Use OUTPUT clause in the MERGE command for such cases.
DECLARE #a1 AS tvp;
DECLARE #a2 AS tvp
INSERT INTO #a1 (name, age, otherid) VALUES ('yy', 10, 99999), ('bb', 20, 88888);
MERGE A a
USING #a1 a1
ON a1.id =a.[id_A]
WHEN NOT MATCHED THEN
INSERT (name, age)
VALUES (a1.name, a1.age)
OUTPUT inserted.id_A,
a1.otherId,
inserted.name,
inserted.age
INTO #a2;
INSERT INTO B (id_A, otherid) SELECT id, otherid FROM #a2
I am trying to insert multiple records (~250) in a table (say MyTable) and would like to insert a new row only if it does not exist already.
I am using SQL Server 2008 R2 and got help from other threads like SQL conditional insert if row doesn't already exist.
While I am able to achieve that with following stripped script, I would like to know if there is a better (short) way to do this as I
have to repeat this checking for every row inserted. Since we need to execute this script only once during DB deployment, I am not too much
worried about performance.
INSERT INTO MyTable([Description], [CreatedDate], [CreatedBy], [ModifiedDate], [ModifiedBy], [IsActive], [IsDeleted])
SELECT N'ababab', GETDATE(), 1, NULL, NULL, 1, 0
WHERE NOT EXISTS(SELECT * FROM MyTable WITH (ROWLOCK, HOLDLOCK, UPDLOCK)
WHERE
([InstanceId] IS NULL OR [InstanceId] = 1)
AND [ChannelPartnerId] IS NULL
AND [CreatedBy] = 1)
UNION ALL
SELECT N'xyz', 1, GETDATE(), 1, NULL, NULL, 1, 0
WHERE NOT EXISTS(SELECT * FROM [dbo].[TemplateQualifierCategoryMyTest] WITH (ROWLOCK, HOLDLOCK, UPDLOCK)
WHERE
([InstanceId] IS NULL OR [InstanceId] = 1)
AND [ChannelPartnerId] IS NULL
AND [CreatedBy] = 1)
-- More SELECT statements goes here
You could create a temporary table with your descriptions, then insert them all into the MyTable with a select that will check for rows in the temporary table that is not yet present in your destination, (this trick in implemented by the LEFT OUTER JOIN in conjunction with the IS NULL for the MyTable.Description part in the WHERE-Clause):
DECLARE #Descriptions TABLE ([Description] VARCHAR(200) NOT NULL )
INSERT INTO #Descriptions ( Description )VALUES ( 'ababab' )
INSERT INTO #Descriptions ( Description )VALUES ( 'xyz' )
INSERT INTO dbo.MyTable
( Description ,
CreatedDate ,
CreatedBy ,
ModifiedDate ,
ModifiedBy ,
IsActive ,
IsDeleted
)
SELECT d.Description, GETDATE(), 1, NULL, NULL, 1, 0
FROM #Descriptions d
LEFT OUTER JOIN dbo.MyTable mt ON d.Description = mt.Description
WHERE mt.Description IS NULL
In the data below I am looking for a query so I can join the results of the 2 tables by nearest neighbor.
Some of the results in dbo.Interests Table will not be in the dbo.Details Table,
This Question finds the k nearest poins for a single point, I need this query to further reconcile data between the 2 tables
How can I extend this SQL query to find the k nearest neighbors?
IF OBJECT_ID('dbo.Interests', 'U') IS NOT NULL DROP TABLE dbo.Interests;
IF OBJECT_ID('dbo.Details', 'U') IS NOT NULL DROP TABLE dbo.Details;
CREATE TABLE [dbo].[Interests](
[ID] [int] IDENTITY(1,1) NOT NULL,
[NAME] [nvarchar](255) NULL,
[geo] [geography] NULL,
)
CREATE TABLE [dbo].[Details](
[ID] [int] IDENTITY(1,1) NOT NULL,
[NAME] [nvarchar](255) NULL,
[geo] [geography] NULL,
)
/*** Sample Data ***/
/* Interests */
INSERT INTO dbo.Interests (Name,geo) VALUES ('Balto the Sled Dog',geography::STGeomFromText('POINT(-73.97101284538104 40.769975451779729)', 4326));
INSERT INTO dbo.Interests (Name,geo) VALUES ('Albert Bertel Thorvaldsen',geography::STGeomFromText('POINT(-73.955996808113582 40.788611756916609)', 4326));
INSERT INTO dbo.Interests (Name,geo) VALUES ('Alice in Wonderland',geography::STGeomFromText('POINT(-73.966714294355356 40.7748020248959)', 4326));
INSERT INTO dbo.Interests (Name,geo) VALUES ('Hans Christian Andersen',geography::STGeomFromText('POINT(-73.96756141015176 40.774416211045626)', 4326));
/* Details */
INSERT INTO dbo.Details(Name,geo) VALUES ('Alexander Hamilton',geography::STGeomFromText('POINT(-73.9645616688172 40.7810234271951)', 4326));
INSERT INTO dbo.Details(Name,geo) VALUES ('Arthur Brisbane',geography::STGeomFromText('POINT(-73.953249720745731 40.791599412827864)', 4326));
INSERT INTO dbo.Details(Name,geo) VALUES ('Hans Christian Andersen',geography::STGeomFromText('POINT(-73.9675614098224 40.7744162102582)', 4326));
INSERT INTO dbo.Details(Name,geo) VALUES ('Balto',geography::STGeomFromText('POINT(-73.9710128455336 40.7699754516397)', 4326));
A brute force approach will be to compute the distance between all details X interests records:
SELECT *
FROM
(
SELECT *, rank=dense_rank() over (partition by IName, IGeo order by dist asc)
FROM
(
SELECT D.NAME as DName, D.geo as DGeo,
I.NAME as IName, I.geo as IGeo,
I.geo.STDistance(D.geo) AS dist
FROM dbo.Details D CROSS JOIN dbo.Interests I
) X
) Y
WHERE rank <= #k
NotE: #k is the target number of matches you are after
I have multiple groups of duplicates in one table (3 records for one, 2 for another, etc) - multiple rows where more than 1 exists.
Below is what I came up with to delete them, but I have to run the script for however many duplicates there are:
set rowcount 1
delete from Table
where code in (
select code from Table
group by code
having (count(code) > 1)
)
set rowcount 0
This works well to a degree. I need to run this for every group of duplicates, and then it only deletes 1 (which is all I need right now).
If you have a key column on the table, then you can use this to uniquely identify the "distinct" rows in your table.
Just use a sub query to identify a list of ID's for unique rows and then delete everything outside of this set. Something along the lines of.....
create table #TempTable
(
ID int identity(1,1) not null primary key,
SomeData varchar(100) not null
)
insert into #TempTable(SomeData) values('someData1')
insert into #TempTable(SomeData) values('someData1')
insert into #TempTable(SomeData) values('someData2')
insert into #TempTable(SomeData) values('someData2')
insert into #TempTable(SomeData) values('someData2')
insert into #TempTable(SomeData) values('someData3')
insert into #TempTable(SomeData) values('someData4')
select * from #TempTable
--Records to be deleted
SELECT ID
FROM #TempTable
WHERE ID NOT IN
(
select MAX(ID)
from #TempTable
group by SomeData
)
--Delete them
DELETE
FROM #TempTable
WHERE ID NOT IN
(
select MAX(ID)
from #TempTable
group by SomeData
)
--Final Result Set
select * from #TempTable
drop table #TempTable;
Alternatively you could use a CTE for example:
WITH UniqueRecords AS
(
select MAX(ID) AS ID
from #TempTable
group by SomeData
)
DELETE A
FROM #TempTable A
LEFT outer join UniqueRecords B on
A.ID = B.ID
WHERE B.ID IS NULL
It is frequently more efficient to copy unique rows into temporary table,
drop source table, rename back temporary table.
I reused the definition and data of #TempTable, called here as SrcTable instead, since it is impossible to rename temporary table into a regular one)
create table SrcTable
(
ID int identity(1,1) not null primary key,
SomeData varchar(100) not null
)
insert into SrcTable(SomeData) values('someData1')
insert into SrcTable(SomeData) values('someData1')
insert into SrcTable(SomeData) values('someData2')
insert into SrcTable(SomeData) values('someData2')
insert into SrcTable(SomeData) values('someData2')
insert into SrcTable(SomeData) values('someData3')
insert into SrcTable(SomeData) values('someData4')
by John Sansom in previous answer
-- cloning "unique" part
SELECT * INTO TempTable
FROM SrcTable --original table
WHERE id IN
(SELECT MAX(id) AS ID
FROM SrcTable
GROUP BY SomeData);
GO;
DROP TABLE SrcTable
GO;
sys.sp_rename 'TempTable', 'SrcTable'
You can alternatively use ROW_NUMBER() function to filter out duplicates
;WITH [CTE_DUPLICATES] AS
(
SELECT RN = ROW_NUMBER() OVER (PARTITION BY SomeData ORDER BY SomeData)
FROM #TempTable
)
DELETE FROM [CTE_DUPLICATES] WHERE RN > 1
SET ROWCOUNT 1
DELETE Table
FROM Table a
WHERE (SELECT COUNT(*) FROM Table b WHERE b.Code = a.Code ) > 1
WHILE ##rowcount > 0
DELETE Table
FROM Table a
WHERE (SELECT COUNT(*) FROM Table b WHERE b.Code = a.Code ) > 1
SET ROWCOUNT 0
this will delete all duplicate rows, But you can add attributes if you want to compare according to them .