In my SQL table, I have a column named "user_id" with comma separated value like this: a,b,c,d and I just wonder how can I update this column without removing old values. I want to update this column to a,b,c,d,e and in other step to a,b,c,d,e,f.
I wrote this query, but it removes old values and does not not update values with comma separated list:
UPDATE multiusers SET user_id = '" . $userID . "' WHERE hwid = '" . $hwid."'
If you want to update a column and append a value just do :-
UPDATE multiusers
SET user_id = user_id + "new user"
WHERE hwid = $hwid
This just appends a value to the existing value in SQL SERVER db at least, other databases may have different concatenation methods. I think your questions points to a fundamental design issue in your database and I would suggest rethinking this.
You are treating a field as a table. Even when you can do, it's a very bad approach. You should have as many records on multiusers table as userid's you have. But if you insist in your approach then you will have to create a quite complex query to retrieve the value of userid field, move to an array and compare it with the new value to make sure you doesn't insert duplicates in the field. Something like a cursor may work for you.
Related
I have a database where is supposed to have only one register with 2 value columns that can be filled by my web application. The values to one of the columns where given to me in an excel and we had to put it into the database. The person who did that, should had used an "update if exists else insert" but he didn't. Now, we have for some data, duplicate lines, one having just the column "valor_realizado_oficial" filled (with the column adt_login filled with 'talend' and with the key columns filled too), and another with the other column filled by the application.
So:
If exists two lines, I would like to copy the value of the column "valor_realizado_oficial" from the line with adt_login like 'talend' to the other line and delete this line.
If exists just one line, do nothing.
I tried to perform the copy part with:
update indicador_val iv
set valor_realizado_oficial=carga.valor_realizado_oficial
from (
select valor_realizado_oficial, ano, municipio_fk, indicador_fk, und_federativa_fk
from indicador_val
where adt_login like 'talend' and ano=2013 ) carga
where iv.ano=2013 and iv.municipio_fk=carga.municipio_fk
and iv.indicador_fk=carga.indicador_fk and iv.ano=carga.ano
and iv.und_federativa_fk = carga.und_federativa_fk;
But 0 rows where affected. Here's an example of a pair of lines:
id; adt_login; ano; valor_estimado, valor_realizado_oficial, indicador_fk, municipio_fk, und_federativa_fk
313885; "talend";2013;;888;2;2202;
291998;"suagenda";2013;900;;2;2202;
And I would like to have just the second, with values:
291998;"suagenda";2013;900;888;2;2202;
What I did wrong? Thanks.
In the sample data, there are empty columns. For example, the last one: und_federativa_fk.
Some of these columns are used in your joining conditions in the correlated UPDATE. If these empty values translate to the SQL NULL value, you should realize that NULL=NULL as a condition is going to be NULL, which means false in this context.
That alone might explain why no row get updated.
The solution is to use IS NOT DISTINCT FROM as the comparison operator for values that may be null.
Example:
where iv.ano=2013 and iv.municipio_fk IS NOT DISTINCT FROM carga.municipio_fk
and iv.indicador_fk IS NOT DISTINCT FROM carga.indicador_fk
etc...
I have 2 sqlite databases, and I'm trying to insert data from one database to another. For example, "db-1.sqlite" has a table '1table' with 2 columns ('name', 'state'). Also, "db-2.sqlite" has a table '2table' with 2 columns ('name', 'url'). Both tables contain a list of 'name' values that are mostly common with each other but randomized, so the id of each row does not match.
I want to insert the values for the 'url' column into the db-1's table, but I want to make sure each url value goes to its corresponding 'name' value.
So far, I have done this:
> sqlite3 db-1.sqlite
sqlite> alter table 1table add column url;
sqlite> attach database 'db-2.sqlite' as db2;
Now, the part I'm not sure about:
sqlite> insert into 1table(url) select db2.2table.url from db2.2table where 1table.name==db2.2table.name
If you look at what I wrote above, you can tell what I'm trying to accomplish, but it is incorrect. If I can get any help on the matter, I'd be very grateful!!
The equality comparison operator in SQL is =, not ==.
Also, I suspect that you should be updating 1table, rather then inserting in it.
Finally, your table names start with digits, so you need to escape them.
This SQL should work better:
update `1table`
set url = (select db2.`2table`.url
from db2.`2table`
where `1table`.name = db2.`2table`.name);
In SQL insert, generally we specify the names of the columns in the SQL. Is there a way to generate that dynamically? basically if we specify the names of columns then tomorrow if a new col is added, there is a code change involved. How can i avoid this?
I am thinking of follg solution -
How about getting the names of the columns via
select column_name,* from information_schema.columns where table_name = '' order by ordinal_position;
& then create the INSERT statement with the columns? This way we do not specify the column names in the SQL...
Any thoughts?
You can only leave out the column names if you fill all values, but that would also break if a new column is added.
If you specify the names, you can add new columns as much as you want. They will automatically be assigned their default value if you leave your query as it is.
If you don't want them to have the default value, you need to edit the code anyway. Sure, you can dynamically generate the SQL and assign a default value, but that is what your RDBMS does anyway! I don't see your problem.
You can use a default value for the new column.
Assuming you're saying that you'll be getting the column values as input from somewhere else, then you could keep the column names in a config file like a properties file. Then if you're willing to assume that the ordering will always match up, just match up the input values to the column names from the file, and adding a column just means getting a new value to match the new column.
I solved this by getting the names of the columns via
select column_name,* from information_schema.columns where table_name = '' order by ordinal_position;
& then create the INSERT statement with the columns. By this I avoided specifying the column names in the query
I have created a lookup table in Access to provide the possible values for a column. Now I need to update this column with the data it had before I converted the column. I am unable to figure out a SQL Query that will work. I keep getting the error "An UPDATE or DELETE query cannot contain a multi-valued field." My research has suggested that I just need to set the value of the column but this always updates 0 records:
UPDATE [table_name] SET [column_name].Value = 55 WHERE [table_name].ID = 16;
I know this query will work if I change it to update a text column, so it is definitely a problem with just this column.
If you're adding a value to your multi-valued field, use an append query.
INSERT INTO table_name( [column_name].Value )
VALUES (55)
WHERE ID = 16;
If you want to change one particular value which exists in your multi-valued field, use an UPDATE statement. For example, to change the 55 to 56 ...
UPDATE [table_name]
SET [column_name].Value = 56
WHERE [column_name].Value = 55 And ID = 16;
See Using multivalued fields in queries for more information.
I have figured this out! It certainly was counter-intuitive! You have to use an INSERT statement to do the update.
-- Update a record with a multi-valued field that has no value
INSERT INTO [table_name] ( [[column_name].[Value] )
VALUES(55)
WHERE [table_name].ID = 16;
This confused me because I was expecting an UPDATE statement. I think it actually inserts a record into a hidden table that is used to associate multiple values with this column.
I am working with Sharepoint, I created the tables as multi-value fields, ran into the error with my INSERT INTO statement, went back to Sharepoint to change to non-multi-value fields, but that didn't fix it.
Recreated the table without using multi-value fields, and the INSERT INTO worked just fine.
do not use the .value part
UPDATE [table_name] SET [column_name] = 55 WHERE [table_name].ID = 16;
INSERT INTO Quals (cTypes.[value])
SELECT Quals_ContractTypes.ContractType
FROM Quals_ContractTypes
WHERE (Quals.ID = Quals_ContractTypes.ID_Quals);
I gotta say I didn't understand very well your problem but I saw something strange in your query. Try this:
UPDATE [table_name] SET [column_name]= 55 WHERE [table_name].ID = 16;
UPDATE:
Look at this link: it has an example
UPDATE Issues
SET Issues.AssignedTo.Value = 10
WHERE (((Issues.AssignedTo.Value)=6)
AND ((Issues.ID)=8));
NOTES
You should always include a WHERE
clause that identifies only the
records that you want to update.
Otherwise, you will update records
that you did not intend to change. An
Update query that does not contain a
WHERE clause changes every row in the
table. You can specify one value to
change.
The Multi-Valued field refers to Access databases that have tables with columns, that allow you to select multiple values, like a Combo Checkbox list.
THOSE are the only Access types that SQL cannot work with. I've tested all Access lookup possibilities, including hard-coded values, and lookup tables. They work fine, but if you have a column that has the Allow Multiple select options, you're out of luck. Even using the INSERT INTO as mentioned below, will not work as you'll get a similar but different error, about INSERTing into multi-valued fields.
As mentioned it's best to avoid using such tables outside of Access, and refer to a table specifically for your external needs. Then write a macro/vba script to update the real tables with the data from the "auxiliary" table.
I need to run a script to update a field of a table in mysql by reversing the string stored in another field of the same table. Original column is term and the one to be filled with the reversed is revTerm. I use this, but it produce an error. Any suggestions?
UPDATE `tu_cla_terms` WHERE tId = '11583' SET revTerm = REVERSE(term)
You have the syntax of an UPDATE query wrong. SET comes before WHERE:
UPDATE `tu_cla_terms` SET revTerm = REVERSE(term) WHERE tId = '11583'
If tId is a numeric column you don't want quotes around its value either.