Insert a row if it doesn't exist via query - sql

I am trying to write a query that will insert a group of people into a table if that person does not exist. For example, I have table full of people and I need to add more people into the database and I don't know if they are already there. I do know that the social security number (ssn) will never be the same for two people. Could a query be used to check if the ssn is in the table and if not insert the person into the table? If the ssn is in the table then go to the next person and check?
I was thinking about using a stored procedure, but I do not have any rights to create a store procedure.

You can insert your data into a table variable or temp table and then INSERT INTO table from temp table where it does not exists in your table.
DECLARE #Inserted AS TABLE
(
NAME VARCHAR(50)
,SSN DECIMAL(10, 0)
)
INSERT INTO #Inserted
( NAME, SSN )
VALUES ( 'Bob', 123456789 )
, ( 'John', 123546789 )
, ( 'James', 123456798 )
INSERT INTO MyTable
SELECT *
FROM #Inserted AS i
LEFT OUTER JOIN MyTable AS m
ON i.SSN = m.SSN
WHERE m.SSN IS NULL

Here are a couple ideas to get you started. I use MERGE a lot because it offers so much control. You could also look into the IN clause as part of a WHERE predicate in the INSERT SELECT statement.
MERGE
DECLARE #PERSONTABLE TABLE (ID INT PRIMARY KEY IDENTITY(1,1), FirstName VARCHAR(max))
INSERT INTO #PERSONTABLE (FirstName) VALUES ('Bill'),('Sally'),('Bob')
DECLARE #NEWPEOPLE TABLE (FirstName VARCHAR(max))
INSERT INTO #NEWPEOPLE (FirstName) VALUES ('Jim'), ('Sally')
--MERGE
MERGE INTO #PERSONTABLE AS T
USING #NEWPEOPLE AS S
ON (T.FirstName = S.FirstName)
WHEN NOT MATCHED BY TARGET THEN
INSERT (FirstName) VALUES (S.FirstName);
SELECT * FROM #PERSONTABLE
EXCEPT
DECLARE #PERSONTABLE TABLE (ID INT PRIMARY KEY IDENTITY(1,1), FirstName VARCHAR(max))
INSERT INTO #PERSONTABLE (FirstName) VALUES ('Bill'),('Sally'),('Bob')
DECLARE #NEWPEOPLE TABLE (FirstName VARCHAR(max))
INSERT INTO #NEWPEOPLE (FirstName) VALUES ('Jim'), ('Sally')
--EXCEPT
INSERT INTO #PERSONTABLE (FirstName)
SELECT FirstName FROM #NEWPEOPLE
EXCEPT
SELECT FirstName FROM #PERSONTABLE
SELECT * FROM #PERSONTABLE

You could do it like this if the new people are in another table. If not, then use Vladimir's solution.
INSERT INTO People(ssn, firstname, lastname)
SELECT ssn, firstname, lastname
FROM newpeople
WHERE ssn not in (select ssn from people )

INSERT INTO People(ssn, firstname, lastname)
SELECT np.ssn, np.firstname, np.lastname
FROM newpeople np
LEFT JOIN People p on np.ssn = p.ssn
WHERE p.ssn IS NULL
Here's another option I use a lot. Normally joins are better than sub-selects... if the joined table value is null you know you don't have a hit in the joined table.

Related

Create a copy of an existing record into a new row and update a few value [duplicate]

I have a table in which I need to copy certain rows. I can get IDs of new rows like this:
DECLARE #IDs TABLE (ID int)
INSERT T (name, address)
OUTPUT INSERTED.TID INTO #ids
SELECT name, address
FROM T
But what I would like to have is something like this:
DECLARE #IDs TABLE (oldID int, newID int)
INSERT T (name, address)
OUTPUT T.ID, INSERTED.TID INTO #ids
SELECT name, address
FROM T
Can this be done with SQL Server?
P.S. I'm not doing this programmaticaly, because it has to be done by a stored procedure.
With helpful links from Andriy M's link to 'How to copy tables avoiding cursors in SQL?', I managed to come up with this very elegant solution:
DECLARE #t TABLE (oID int, nID int);
MERGE T s
USING (
SELECT TID, name, address
FROM T [s]
) d on 0 = 1
WHEN NOT MATCHED
THEN INSERT (name, address)
VALUES (name, address)
OUTPUT d.TID as oID, Inserted.TID as nID
INTO #t;

I need to migrate data from one old table to a new table by storing appropriate CityId instead CityName

I'm migrating data from one table to another table in SQL Server, In this process what I need to do is "I have 10 columns in old table one column is 'CityName' which is varchar and in the new table, I have a column 'CityId' which is an integer. And I have other table which has data about city id and names. I need store the appropriate cityId in new table instead of CityName. Please help me. Thanks in advance.
You'll need to join the source table to the CityName field in the city information table:
INSERT INTO dbo.Destination (CityID, OtherStuff)
SELECT t1.CityID, t2.OtherStuff
FROM CityInformationTable t1
INNER JOIN SourceTable t2
ON t1.CityName = t2.CityName
Below should give you an idea, you need to inner join to your look up table to achieve this.
declare #t_cities table (Id int, City nvarchar(20))
insert into #t_cities
(Id, City)
values
(1, 'London'),
(2, 'Dublin'),
(3, 'Paris'),
(4, 'Berlin')
declare #t table (City nvarchar(20), SomeColumn nvarchar(10))
insert into #t
values
('London', 'AaaLon'),
('Paris', 'BeePar'),
('Berlin', 'CeeBer'),
('London', 'DeeLon'),
('Dublin', 'EeeDub')
declare #finalTable table (Id int, SomeColumn nvarchar(10))
insert into #finalTable
select c.Id, t.SomeColumn
from #t t
join #t_cities c on c.City = t.City
select * from #finalTable
Output:
Id SomeColumn
1 AaaLon
3 BeePar
4 CeeBer
1 DeeLon
2 EeeDub

Update temp table with identity after insert

I have a temp table that looks like this:
FirstName
LastName
DOB
Sex
Age
ExternalID
In my stored procedure I'm inserting these values into a regular table that has the following structure:
ID identity(1,1)
FirstName
LastName
So, I do this:
Insert into myTable
select FirstName, LastName from TempTable
During the insert I need to insert primary key from main table back into temp table "ExternalID" column. How can this be achieved?
I tried using OUTPUT statement but it only allows to insert to a separate table and then I have no way to map back to temp table
I need to insert generated IDs to column ExternalID in temp table right after the insert. FirstName and LastName are not unique.
One possible solution would be to use loop and insert one row at a time. This way, I can update temp table row with scope_identity(). But I want to avoid using loops.
Try using MERGE instead of INSERT.
MERGE allows you to output a column you didn't insert, such as an identifier on your temp table. Using this method, you can build another temporary table that maps your temp table to the inserted rows (named #TempIdTable in the sample below).
First, give #TempTable its own primary key. I'll call it TempId. I'll also assume you have a column on #TempTable to store the returned primary key from MyTable, ID.
--Make a place to store the associated ID's
DECLARE #TempIdTable TABLE
([TempId] INT NOT NULL
,[ID] INT NOT NULL)
--Will only insert, as 1 never equals 0.
MERGE INTO myTable
USING #TempTable AS tt
ON 1 = 0
WHEN NOT MATCHED
THEN
INSERT ([FirstName]
,[LastName])
VALUE (t.[FirstName]
,t.[LastName])
OUTPUT tt.[TempId], inserted.[ID] --Here's the magic
INTO #TempIdTable
--Associate the new primary keys with the temp table
UPDATE #TempTable
SET [ID] = t.[ID]
FROM #TempIdTable t
WHERE #TempTable.[TempId] = t.[TempId]
I was working on a similar issue and found this trick over here: Is it possible to for SQL Output clause to return a column not being inserted?
Here's the full code I used in my own testing.
CREATE TABLE [MQ]
([MESSAGEID] INT IDENTITY PRIMARY KEY
,[SUBJECT] NVARCHAR(255) NULL);
CREATE TABLE [MR]
([MESSAGESEQUENCE] INT IDENTITY PRIMARY KEY
,[TO] NVARCHAR(255) NOT NULL
,[CC] NVARCHAR(255) NOT NULL
,[BCC] NVARCHAR(255) NOT NULL);
CREATE TABLE #Messages (
[subject] nvarchar(255) NOT NULL
,[to] nvarchar(255) NOT NULL
,[cc] nvarchar(255) NULL
,[bcc] nvarchar(255) NULL
,[MESSAGEID] INT NULL
,[sortKey] INT IDENTITY PRIMARY KEY
);
INSERT INTO #Messages
VALUES ('Subject1','to1','cc1','bcc1', NULL)
,('Subject2','to2', NULL, NULL, NULL);
SELECT * FROM #Messages;
DECLARE #outputSort TABLE (
[sortKey] INT NOT NULL
,[MESSAGEID] INT NOT NULL
,[subject] NVARCHAR(255)
);
MERGE INTO [MQ]
USING #Messages M
ON 1 = 0
WHEN NOT MATCHED
THEN
INSERT ([SUBJECT])
VALUES (M.[subject])
OUTPUT M.[SORTKEY]
,inserted.[MESSAGEID]
,inserted.[SUBJECT]
INTO #outputSort;
SELECT * FROM #outputSort;
SELECT * FROM [MQ];
UPDATE #Messages
SET MESSAGEID = O.[MESSAGEID]
FROM #outputSort O
WHERE #Messages.[sortKey] = O.[sortKey];
SELECT * FROM #Messages;
DROP TABLE #Messages;
As you said, FirstName and LastName are not unique. This means you cannot use a trigger because there can be the same FirstName + LastName so you cannot join on them.
But you can do the inverse thing: first update your temp table ExternalID (I suggest you to use sequence object and just do update #t set ExternalID = next value for dbo.seq1;) and then just insert your rows including ExternalID into myTable. To be able to insert into identity field you can use set identity_insert myTable on or you can re-design your destination table to contain no identity at all as now you use sequence for the same purpose.
We need a unique column for able to make the comparison at the update operation after the insert. That's why we are using ExternalID column temporarily. ExternalID updated by row_nubmber.
;WITH CTE AS
(
SELECT *, RN = ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) FROM #TempTable
)
UPDATE CTE SET ExternalID = RN
We are keeping the output of the insert operation in a temp table. The trick is order by with ExternalID, it will help us for making the unique row number for same first and last name
DECLARE #output TABLE (
ID INT,
FirstName VARCHAR(10),
LastName VARCHAR(10))
Insert into #myTable
OUTPUT inserted.ID, inserted.FirstName, inserted.LastName INTO #output(ID, FirstName, LastName)
select FirstName, LastName from #TempTable T
order by ExternalID
For replacing the ExternalID column with inserted id value, we are making comparing with first name, last name and row number.
;WITH TMP_T AS(
SELECT *, RN = ROW_NUMBER() OVER(PARTITION BY FirstName, LastName ORDER BY ExternalID) FROM #TempTable )
,OUT_T AS(
SELECT *, RN = ROW_NUMBER() OVER(PARTITION BY FirstName, LastName ORDER BY ID) FROM #output )
UPDATE TMP_T SET ExternalID = OUT_T.ID
FROM
TMP_T INNER JOIN OUT_T ON
TMP_T.FirstName = OUT_T.FirstName
AND TMP_T.LastName = OUT_T.LastName
AND TMP_T.RN = OUT_T.RN
Sample Data:
DECLARE #TempTable TABLE (
FirstName VARCHAR(10),
LastName VARCHAR(10),
DOB VARCHAR(10),
Sex VARCHAR (10),
Age VARCHAR(10),
ExternalID INT)
INSERT INTO #TempTable VALUES
('Serkan1', 'Arslan1', 'A','M','1',NULL),
('Serkan2', 'Arslan2', 'B','M','1',NULL),
('Serkan3', 'Arslan', 'C','M','1',NULL),
('Serkan3', 'Arslan', 'D','M','1',NULL)
DECLARE #myTable TABLE (
ID INT identity(100,1), -- started from 100 for see the difference
FirstName VARCHAR(10),
LastName VARCHAR(10))
Result:
MyTable
ID FirstName LastName
----------- ---------- ----------
100 Serkan1 Arslan1
101 Serkan2 Arslan2
102 Serkan3 Arslan
103 Serkan3 Arslan
TempTable
FirstName LastName DOB Sex Age ExternalID
---------- ---------- ---------- ---------- ---------- -----------
Serkan1 Arslan1 A M 1 100
Serkan2 Arslan2 B M 1 101
Serkan3 Arslan C M 1 102
Serkan3 Arslan D M 1 103
One way to do this is by duplicating the data into a second temp table like so:
SELECT *
INTO #TEMPTABLE
FROM (VALUES (1, 'Adam'), (2, 'Kate'), (3, 'Jess')) AS X (Id, Name)
SELECT TOP 0 CAST(NULL AS INT) AS IdentityValue, *
INTO #NEWTEMPTABLE
FROM #TEMPTABLE
CREATE TABLE #TABLEFORINSERT (
IdentityColumn INT IDENTITY(1,1),
Id INT,
Name VARCHAR(255)
)
INSERT INTO #TABLEFORINSERT (Id, Name)
OUTPUT INSERTED.IdentityColumn, INSERTED.Id, Inserted.Name INTO #NEWTEMPTABLE
SELECT Id, Name FROM #TEMPTABLE
--New temp table with identity values
SELECT * FROM #NEWTEMPTABLE

SQL 2 Inserts based on return of first

I am generating a series of Inserts based on data from an Excel file into SQL Server 2014
How do I get the value of the ID of the first INSERT to put into the second
Simplified example where Ontario is a Province of Canada:
Insert into country (Name) values('canada');
Insert into provinces (CountryId, Name) values (???,'ontario');
There are 100 inserts so performance is not an issue.
declare #countryid int
Insert into country (Name) values('canada');
SELECT #countryid = SCOPE_IDENTITY()
Insert into provinces (CountryId, Name) values (#countryid,'ontario');
the answer above from tshoemake shows how you can insert one record and get the result. If you want to insert many records in Country and then many records in provinces, you might want to have a look at the OUTPUT clause. You'll have to work out how to join in your list of provinces because this code will just add Ontario to every country:
create table __country
(
id int identity(1,1) primary key,
Name varchar(5000)
)
CREATE TABLE __Provinces (
countryid int,
name varchar(5000)
)
CREATE TABLE #tempIDs
(
id int
)
INSERT INTO __Country
OUTPUT inserted.id
INTO #tempIDs
values ('canada'), values('USA')
insert into __Provinces
select #tempIDs.id, 'ontario'
from #tempIDs
join __country
ON __country.id = #tempIDs.id
select * from __Provinces

How to copy rows with SQL and get new and old IDs as result?

I have a table in which I need to copy certain rows. I can get IDs of new rows like this:
DECLARE #IDs TABLE (ID int)
INSERT T (name, address)
OUTPUT INSERTED.TID INTO #ids
SELECT name, address
FROM T
But what I would like to have is something like this:
DECLARE #IDs TABLE (oldID int, newID int)
INSERT T (name, address)
OUTPUT T.ID, INSERTED.TID INTO #ids
SELECT name, address
FROM T
Can this be done with SQL Server?
P.S. I'm not doing this programmaticaly, because it has to be done by a stored procedure.
With helpful links from Andriy M's link to 'How to copy tables avoiding cursors in SQL?', I managed to come up with this very elegant solution:
DECLARE #t TABLE (oID int, nID int);
MERGE T s
USING (
SELECT TID, name, address
FROM T [s]
) d on 0 = 1
WHEN NOT MATCHED
THEN INSERT (name, address)
VALUES (name, address)
OUTPUT d.TID as oID, Inserted.TID as nID
INTO #t;