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);
Related
I want to append new rows to a table-1 d:\dl based on the equality constraint lower(rdl.subdir) = lower(tr.n1), where rdl and tr would be prospective aliases for f:\rdl and f:\tr tables respectively.
I get a function name is missing ). message when running the following command in VFP9:
INSERT INTO d:\dl SELECT * FROM f:\rdl WHERE (select LOWER(subdir)FROM f:\rdl in (select LOWER(n1) FROM f:\tr))
I am using the in syntax, instead of the alias based equality statement lower(rdl.subdir) = lower(tr.n1) because I do not know where to define aliases within this command.
In general, the best way to get something like this working is to first make the query work and give you the results you want, and then use it in INSERT.
In general, in SQL commands you assign aliases by putting them after the table name, with or without the keyword AS. In this case, you don't need aliases because the ones you want are the same as the table names and that's the default.
If what you're showing is your exact code and you're running it in VFP, the first problem is that you're missing the continuation character between lines.
You're definitely doing too much work, too. Try this:
INSERT INTO d:\dl ;
SELECT * ;
FROM f:\rdl ;
JOIN f:\tr ;
ON LOWER(rdl.subdir) = LOWER(tr.n1)
So I am comparing two Oracle databases by grabbing random rows in database A, and searching for these rows in database B based off their key columns. Then I compare the rows which are returned in java.
I am using the following query to find rows in database B using the key columns from database A:
select * from mytable
Where (Key_Column_A,Key_Column_B,Key_Column_C)
in (('1','A', 'cat'),('2','B', 'dog'),('3','C', ''));
This works just fine for the first two sets of keys, but the third key('3','C', '') does not work because there is a null value in the third column. Changing the statement to ('3','C', NULL) or changing the SQL to
select * from mytable
Where (Key_Column_A,Key_Column_B,Key_Column_C)
in ((('1','A', 'cat'),('2','B', 'dog'),('3','C', ''))
OR (Key_Column_A,Key_Column_B,Key_Column_C) IS NULL);
will not work either.
Is there a way to include a null column in an IN clause? And if not, is there a way to efficiently do the same thing? (My only solution currently is to create a check to make sure there are no nullable columns in my keys which would make this process rather unefficient and somewhat messy).
You can use it this way. I think it would work.
select * from mytable
Where (NVL(Key_Column_A,''),NVL(Key_Column_B,''),NVL(Key_Column_C,''))
in (('1','A', 'cat'),('2','B', 'dog'),('3','C', ''));
I am not sure about this (Key_Column_A,Key_Column_B,Key_Column_C) IS NULL. Wouldn't this imply that all of the columns (A,B,C) are NULL ?
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 a unique column. I also have a known set of elements that are possible values for the column. I need to know which of the possible values are not already in the table, and as such, are suitable for insertion.
Is this possible with SQL or is post processing required?
Currently, I am using the "in" operator to select all rows where the column value equals an element in my set. Then I remove all matched elements from my set via post processing.
Stick the allowed values in a temporary table allowed, then use a subquery using NOT IN:
SELECT *
FROM allowed
WHERE allowed.val NOT IN (
SELECT maintable.val
)
Some DBs will allow you to build up a table "in-place", instead of having to create a separate table. E.g. in PostgreSQL (any version):
SELECT *
FROM (
SELECT 'foo'
UNION ALL SELECT 'bar'
UNION ALL SELECT 'baz' -- etc.
) inplace_allowed
WHERE inplace_allowed.val NOT IN (
SELECT maintable.val
)
More modern versions of PostgreSQL (and perhaps other DBs) will let you use the slightly nicer VALUES syntax to do the same thing.
To do this entirely in SQL you will need to create a separate table with one column. Each row holds one value from the known set of elements. Assuming the table is called ElementList and the other table is called Existing:
SELECT * FROM ElementList WHERE Element NOT IN
(SELECT DISTINCT Element FROM Existing)
Depending on what database engine you're using you may be able to use a temporary table to create and hold the list without saving it permanently in the database. However, storing the list of allowed elements is valuable for constraining the Element column in the Existing table (and for presenting the user with allowed Elements in the user interface).
I am trying to import a large CSV file into a MySQL database. I have loaded the entire file into one flat table. i can select the data that needs to go into separate tables using select statements, my question is how do i copy the results of those select queries to different tables. i would prefer to do it completely in SQL and not have to worry about using a scripting language.
INSERT
INTO new_table_1
SELECT *
FROM existing_table
WHERE condition_for_table_1;
INSERT
INTO new_table_2
SELECT *
FROM existing_table
WHERE condition_for_table_2;
INSERT INTO anothertable (list, of , column, names, to, give, values, for)
SELECT list, of, column, names, of, compatible, column, types
FROM bigimportedtable
WHERE possibly you want a predicate or maybe not;
The answer from Quassnoi was the one I was looking for. Please observe that if new_table_1 doesn't exist yet the "INSERT INTO" statement has to be replaced with a "CREATE TABLE" statement.