insert a single value into new created column - sql

First of all: It sounds pretty basic to me, but i did not find anything on this topic that comes close.
I am using pl-sql and have a table thats contains records. Now i have created a new column and want to insert an entry when specific conditions given. Something like this
insert into myTable (newColumn)
values (newValue)
where oldColumn = 'something';
Obviously this doesn't work.
Is this
possible with an insert statement or do i have to undo the whole row and rewrite it with the old values and the new one?
Thanks, newbie.

I think you want update, not insert:
updatE myTable
set newColumn = newValue
where oldColumn = 'something';

Please use update query instead of insert as your table is ready with records and you have added a new column to existing table that is having values in it.
syntax is as follows:
UPDATE new_column_name
SET new_column_name='Dummy value' where (condition)

You are trying to add values to a new column. But its corresponding row is already there. So you need to update the row, not insert. You can do like,
updatE myTable
set newColumn = newValue
where oldColumn = 'something';

Related

Trigger is not inserting value into correct record

I'm trying to write a trigger that get a QuoteNumber from table 1 and insert it into table 2 where ShippingIdentity matches the records in both tables. The problem is the QuoteNumber is being inserted into it's own row(record) Can anyone please let me know why? Thanks.
ALTER TRIGGER InsertQuoteNumber
ON AccountInfo
FOR INSERT
AS
BEGIN
INSERT INTO ShippingInfo (QuoteNumber)
SELECT a.QuoteNumber
FROM AccountInfo a
inner join inserted i on a.ShippingIdentity = i.ShippingIdentity
END
You use the word "insert" in your description, but I think what you mean is "update". That is, you want to modify an existing row in ShippingInfo to reflect the new quote number.
The problem in your code is as simple as your choice of words. You are using an INSERT command, which inserts a new row. If you want to update an existing row, use an UPDATE.

SQL Insert Query With Condition

I am trying to insert values into 1 column of a table when a condition is satisfied.
Note: The table already contains data for all the columns but for 1 which is empty. I would like to insert value into this 1 column depending on the WHERE clause.
I have this query:
INSERT INTO <TABLE_NAME>
(COLUMN_NAME)
(VALUE)
WHERE <CONDITION>
I am getting an exception:
Incorrect Syntax Near WHERE Keyword
I am able to do this using UPDATE:
UPDATE <TABLE_NAME>
SET <COL_NAME>
WHERE <CONDITION>
But was wondering why the INSERT query was failing. Any advise appreciated.
As I understand your problem, you already have data in one row, and one column in that row does not have value, so you want to add value in to that column.
This the scenario for Update existing row, not the insert new row. You have to use UPDATE clause when data already present and you want to modify record(s). Choose insert when You want to insert new row in table.
So in your current scenario, Update Clause is your friend with Where Clause as you want to modify subset of records not all.
UPDATE <TABLE_NAME>
SET <COL_NAME>
WHERE <CONDITION>
INSERT Clause does not have any Where Clause as per any RDBMS syntax(I think). Insert is condition less sql query, While SELECT, UPDATE, DELETE all are conditional commands, you can add Where Clause in all later ones.
In order to add a value into the one column when the rows are already populated, you will need to use the update statement.
If you need to insert a new row that has a where clause, you will need to use an insert into select statement:
INSERT INTO <table> (<columns>)
SELECT <columns>
FROM <table>
WHERE <condition>;
The SQL Insert dont accept where parameters, you could check this: SQL Insert Definition...
I do not know the whole question of what you want to do, but just using the INSERT statement is not possible, however it is possible to condition the insertion of data into a table, if this data is dependent on another table or comes from another table ... check here... SQL Insert explain in wikipedia
like this:
Copying rows from other tables
INSERT INTO phone_book2
SELECT *
FROM phone_book
WHERE name IN ('John Doe', 'Peter Doe')
or
INSERT INTO phone_book2 ( [name], [phoneNumber] )
SELECT [name], [phoneNumber]
FROM phone_book
WHERE name IN ('John Doe', 'Peter Doe')
Based on your question I have the feeling that you are trying to UPDATE a column in a table rather than insert.
Something like:
UPDATE column SET value WHERE different_column_value = some_value
I know this is kinda late, for those who still want to use the where clause in an insert query, it's kinda possible with a hack.
My understanding is that, you want to insert only if a condition is true. Let's assume you have a column in your database "surname" and you want to insert only if a surname doesn't exist from the table.
You kinda want something like INSERT INTO table_name blha blha blah WHERE surname!="this_surname".
The solution is to make that cell unique from your admin panel.
Insert statement will insert a new record. You cannot apply a where clause to the record that you are inserting.
The where clause can be used to update the row that you want.
update SET = where .
But insert will not have a where clause.
Hope this answers your question
INSERT syntax cannot have WHERE clause. The only time you will find INSERT has WHERE clause is when you are using INSERT INTO...SELECT statement.
I take it the code you included is simply a template to show how you structured your query. See the SO questions here, here and the MSDN question here.
In SQL Server (which uses Transact-SQL aka T-SQL) you need an UPDATE query for INSERT where columns already have values - by using the answer #HaveNoDisplayName gave :)
If you are executing INSERT / UPDATE from code (or if you need it regularly) I would strongly recommend using a stored procedure with parameters.
You could extend the procedure further by adding an INSERT block to the procedure using an IF-ELSE to determine whether to execute INSERT new record or UPDATE an existing, as seen in this SO answer.
Finally, take a look at SQLFiddle for a sandbox playground to test your SQL without risk to your RDMS :-)
Private case I found useful: Conditional insert which avoids duplications:
-- create a temporary table with desired values
SELECT 'Peter' FirstName, 'Pan' LastName
INTO #tmp
-- insert only if row doesn't exist
INSERT INTO Persons (FirstName, LastName)
SELECT *
FROM #tmp t
WHERE NOT EXISTS (SELECT * FROM Persons where FirstName=t.FirstName and LastName=t.LastName)
If the data need to be added for a column for an existing row then it’s UPDATE.
INSERT is creating a new row in the table.
For conditional INSERT, you can use the MERGE command.

Does my trigger updates all the records

I have written a simple trigger which sets a column value with the id column value.
This is my trigger.
CREATE TRIGGER SubSectionsPrioritytrigger
ON SubSections
AFTER INSERT
AS
UPDATE dbo.SubSections
SET Priority = Id
After writing this trigger that, does this updates all the records after each insert. Or the only created new row.
Could some one provide any info on this.
Thanks.
To Update just the inserted row, you can do this:
UPDATE dbo.SubSections
SET SubSections.Priority = SubSections.Id
FROM INSERTED
WHERE INSERTED.Id = dbo.SubSections.Id
It does exactly what you wrote
UPDATE dbo.SubSections
SET Priority = Id
Any row will be updated.
You can change this to
UPDATE dbo.SubSections
SET SubSections.Priority = Inserted.Id
FROM INSERTED
WHERE INSERTED.id = SubSections.id
this will affect only the inserted rows.
to update just the last inserted row to what ever value you want you need to specify that row id which makes that row unique, from other rows.
and in your trigger you have not specified a where clause which causes all rows in the table to be updated.
whenever a any operation/event occurs on the table which has trigger associated with it mean a new record is inserted/updated or deleted an magic table is created in memory of SQL Server and we can access that magic table with the keyword "Inserted" in case of insert or Update and "Deleted" in case of delete.
so your query should be like this.
UPDATE dbo.SubSections
SET SubSections.Priority = SubSections.Id
FROM INSERTED
WHERE INSERTED.Id = dbo.SubSections.Id

update column using where clause a same field's multipul values

Dear all,
i need to update a table using same filed's multiple value.
Let: update test_table set column1=123 where column2=100,200,300......
I mean column 2 have multiple values.Now how i write the query??
Please help me.
try
update test_table set column1=123 where column2 IN(100,200,300)
look here for a tutorial:
http://www.webdevelopersnotes.com/tutorials/sql/tutorial_mysql_in_and_between.php3
If you mean that the match should happen where column2's value is one of the items in your list, use:
UPDATE test_table
SET column1=123
WHERE column2 IN (100,200,300, ...)
use FIND_IN_SET
FIND_IN_SET("id",test_table.column2)

How to update multiple rows in the same table of MySQL with PHP?

If only one row with a distinct field is to be updated,I can use:
insert into tab(..) value(..) on duplicate key update ...
But now it's not the case,I need to update 4 rows inside the same table,which have its field "accountId" equal to $_SESSION['accountId'].
What I can get out of my mind at the moment is:
delete from tab where accountId = $_SESSION['accountId'],
then insert the new rows.
Which obviously is not the best solution.
Has someone a better idea about this?
Use the update just like that!
update tab set col1 = 'value' where accountId = $_SESSION['accountId']
Moreover, MySQL allows you to do an update with a join, if that makes your life a bit easier:
update
tab t
inner join accounts a on
t.accountid = a.accountid
set
t.col1 = 'value'
where
a.accountname = 'Tom'
Based on your question, it seems like you should review the Update Statement.
Insert is used to put new rows in - not update them. Delete is used to remove. And Update is used to modify existing rows. Using "Insert On Duplicate Key Update" is a hackish way to modify rows, and is poor form to use when you know the row is already there.
load all of the values in to a temporary table.
UPDATE all of the values using a JOIN.
INSERT all of the values from the temp table that don't exist in the target table.
You can use replace statement. This will work as a DELETE followed by INSERT