I need to insert a row like following:
INSERT INTO table1 (id, name) VALUES (1, SELECT otherName FROM table2);
Is it possible in SQLite?
Here is the syntax you are looking for:
INSERT INTO table1 (id, name)
SELECT 1, otherName
FROM table2
Have a look at this SO article which covers a similar question.
Coming from here : http://www.tutorialspoint.com/sqlite/sqlite_insert_query.htm
You can populate data into a table through select statement over
another table provided another table has a set of fields, which are
required to populate first table. Here is the syntax:
INSERT INTO first_table_name [(column1, column2, ... columnN)]
SELECT column1, column2, ...columnN
FROM second_table_name
[WHERE condition];
This works :
INSERT INTO test2 values(1,(Select name from test1 where id=1))
Here i tested it on SQLite : http://sqlfiddle.com/#!5/9bcff/1
AM using java , so you can use some thing like this
prep = Db_Connector.connection.prepareStatement("insert into reg_member values(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
prep.setString(2, surname);
prep.setString(3, lastname);
prep.execute();
prep.close();
Db_Connector.killObjects(Db_Connector.statement, Db_Connector.connection);
Related
I'm working with SQLite and I have two tables:
table1 table2
------------- --------------
id id
value condition
Column "id" contains the same data. And I need to:
UPDATE table1
SET table1.value = 'Some value'
WHERE table2.condition = 'Some condition"
I tried to use JOIN and FROM for linking tables with "id" column, but this isn`t working in SQLite. Please help with syntax.
You need a correlated subquery in the update, something like this:
UPDATE table1
SET value = 'Some value'
WHERE EXISTS (SELECT 1 FROM table2 t2
WHERE t2.id = table1.id AND
t2.condition = 'Some condition');
Method 1 : Considering the two tables you have are "Table1" and "Table2", Updating Table1 can be done using a nested Select statement in which you will be selecting the data you need to update from Table2. For example:
UPDATE Table1
SET StudentID =
(
SELECT RegNo
FROM Table2 t
WHERE StudentID = RegNo
);
You can have a look on this link which solves a similar question : https://dba.stackexchange.com/questions/206317/update-values-in-one-table-from-data-in-another
Method 2 : You can use a table join. Refer the same link given above.
I have a old table and a new table. what i need is to copy the uuId of the old table to the new Table.
im following some answers from other references but i can`t get the ideal answer.
the closest answer i found is this:
update table1
set table1.uuid =
(select table2.uuid from table2 where table1.itemDescription = table2.itemDescription)
when i execute this query, it only saves the 1st found uuid of the old table to all the entry in the new Table.
Sample Table2 (old table):
uuid|itemDescription
1|item1
2|item2
3|item3
Sample Table1 (new Table):
uuid|itemDescription
Null|item1
Null|item2
Null|item3
Desired Output:
uuid|itemDescription
1|item1
2|item2
3|item3
what happens:
uuid|itemDescription
1|item1
1|item2
1|item3
In SQLite, you must not use the table name in the SET clause:
update table1
set uuid =
(select table2.uuid from table2 where table1.itemDescription = table2.itemDescription);
Try like this :
UPDATE table1
SET table1.uuid = table2.uuid
FROM table2 WHERE table1.itemDescription = table2.itemDescription
No need for subquery, otherwise you need to link item description in outer query also
I have an SQLite database. I am trying to insert values (users_id, lessoninfo_id) in table bookmarks, only if both do not exist before in a row.
INSERT INTO bookmarks(users_id,lessoninfo_id)
VALUES(
(SELECT _id FROM Users WHERE User='"+$('#user_lesson').html()+"'),
(SELECT _id FROM lessoninfo
WHERE Lesson="+lesson_no+" AND cast(starttime AS int)="+Math.floor(result_set.rows.item(markerCount-1).starttime)+")
WHERE NOT EXISTS (
SELECT users_id,lessoninfo_id from bookmarks
WHERE users_id=(SELECT _id FROM Users
WHERE User='"+$('#user_lesson').html()+"') AND lessoninfo_id=(
SELECT _id FROM lessoninfo
WHERE Lesson="+lesson_no+")))
This gives an error saying:
db error near where syntax.
If you never want to have duplicates, you should declare this as a table constraint:
CREATE TABLE bookmarks(
users_id INTEGER,
lessoninfo_id INTEGER,
UNIQUE(users_id, lessoninfo_id)
);
(A primary key over both columns would have the same effect.)
It is then possible to tell the database that you want to silently ignore records that would violate such a constraint:
INSERT OR IGNORE INTO bookmarks(users_id, lessoninfo_id) VALUES(123, 456)
If you have a table called memos that has two columns id and text you should be able to do like this:
INSERT INTO memos(id,text)
SELECT 5, 'text to insert'
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 AND text = 'text to insert');
If a record already contains a row where text is equal to 'text to insert' and id is equal to 5, then the insert operation will be ignored.
I don't know if this will work for your particular query, but perhaps it give you a hint on how to proceed.
I would advice that you instead design your table so that no duplicates are allowed as explained in #CLs answer below.
For a unique column, use this:
INSERT OR REPLACE INTO tableName (...) values(...);
For more information, see: sqlite.org/lang_insert
insert into bookmarks (users_id, lessoninfo_id)
select 1, 167
EXCEPT
select user_id, lessoninfo_id
from bookmarks
where user_id=1
and lessoninfo_id=167;
This is the fastest way.
For some other SQL engines, you can use a Dummy table containing 1 record.
e.g:
select 1, 167 from ONE_RECORD_DUMMY_TABLE
I have one table named Test with columns named ID,Name,UserValue,AverageValue
ID,Name,UserValue,AverageValue (As Appears on Table)
1,a,10,NULL
2,a,20,NULL
3,b,5,NULL
4,b,10,NULL
5,c,25,NULL
I know how to average the numbers via (SELECT Name, AVG(UserValue) FROM Test GROUP BY Name)
Giving me:
Name,Column1(AVG(Query)) (As Appears on GridView1 via databind when I run the website)
a,15
b,7.5
c,25
What I need to do is make the table appear as such by inserting the calculated AVG() into the AverageValue column server side:
ID,Name,UserValue,AverageValue (As Appears on Table)
1,a,10,15
2,a,20,15
3,b,5,7.5
4,b,10,7.5
5,c,25,25
Conditions:
The AVG(UserValue) must be inserted into Test table AverageValue.
If new entries are made the AverageValue would be updated to match AVG(UserValue).
So what I am looking for is a SQL command that is something like this:
INSERT INTO Test (AverageValue) VALUES (SELECT Name, AVG(UserValue) FROM Test GROUP BY Name)
I have spent considerable amount of time searching on google to find an example but have had no such luck. Any examples would be greatly appreciated. Many thanks in advance.
Try this:
with toupdate as (
select t.*, avg(uservalue) over (partition by name) as newavg
from test t
)
update toupdate
set AverageValue = newavg;
The CTE toupdate is an updatable CTE, so you can just use it in an update statement as if it were a table.
I believe this will do the trick for you. I use the merge statement a lot! It's perfect for doing things like this.
Peace,
Katherine
use [test_01];
go
if object_id (N'tempdb..##test', N'U') is not null
drop table ##test;
go
create table ##test (
[id] [int] identity(1, 1) not null,
[name] [nvarchar](max) not null,
[user_value] [int] not null,
[average_value] [decimal](5, 2),
constraint [pk_test_id] primary key([id])
);
go
insert into ##test
([name], [user_value])
values (N'a',10),
(N'a',20),
(N'b',5),
(N'b',10),
(N'c',25);
go
with [average_builder] as (select [name],
avg(cast([user_value] as [decimal](5, 2))) as [average_value]
from ##test
group by [name])
merge into ##test as target
using [average_builder] as source
on target.[name] = source.[name]
when matched then
update set target.[average_value] = source.[average_value];
go
select [id], [name], [user_value], [average_value] from ##test;
go
I am looking to retrieve a list of columns in a table. The database is the latest release of SQLite (3.6, I believe). I am looking for code that does this with a SQL query. Extra bonus points for metadata related to the columns (e.g. length, data type, etc...)
What you're looking for is called the data dictionary. In sqlite a list of all tables can be found by querying sqlite_master table (or view?)
sqlite> create table people (first_name varchar, last_name varchar, email_address varchar);
sqlite> select * from sqlite_master;
table|people|people|2|CREATE TABLE people (first_name varchar, last_name varchar, email_address varchar)
To get column information you can use the pragma table_info(table_name) statement:
sqlite> pragma table_info(people);
0|first_name|varchar|0||0
1|last_name|varchar|0||0
2|email_address|varchar|0||0
For more information on the pragma statements, see the documentation.
Here's the simple way:
.schema <table>
The question is old but the following hasn't been mentioned yet.
Another convenient way in many cases is to turn headers on by:
sqlite> .headers on
Then,
sqlite> SELECT ... FROM table
will display a headline showing all selected fields (all if you SELECT *) at the top of the output.
Here's a SELECT statement that lists all tables and columns in the current database:
SELECT m.name as tableName,
p.name as columnName
FROM sqlite_master m
left outer join pragma_table_info((m.name)) p
on m.name <> p.name
order by tableName, columnName
;
just go into your sqlite shell:
$ sqlite3 path/to/db.sqlite3
and then just hit
sqlite> .schema
and you will get everything.
This is a query that lists all tables with their columns, and all the metadata I could get about each column as OP requested (as bonus points).
SELECT
m.name AS table_name,
p.cid AS col_id,
p.name AS col_name,
p.type AS col_type,
p.pk AS col_is_pk,
p.dflt_value AS col_default_val,
p.[notnull] AS col_is_not_null
FROM sqlite_master m
LEFT OUTER JOIN pragma_table_info((m.name)) p
ON m.name <> p.name
WHERE m.type = 'table'
ORDER BY table_name, col_id
Thanks to #David Garoutte for showing me how to get pragma_table_info to work in a query.
Run this query to see all the table metadata:
SELECT * FROM sqlite_master WHERE type = 'table'
Building on the above, you can do it all at once:
sqlite3 yourdb.db ".schema"
That will give you the SQL to create the table, which is effectively a list of the columns.
In case if you want to get all column names into one single comma separated string, you can use below.
SELECT GROUP_CONCAT(NAME,',') FROM PRAGMA_TABLE_INFO('table_name')
Here the pragma table_info is used as pragma_table_info for the select statement and GROUP_CONCAT is to combine all the field names into one string. for the second parameter of GROUP_CONCAT you can pass the separator.
I know, it’s been a long time but it’s never too late…
I had a similar question with TCL as interpreter and after several search, found nothing good for me. So I propose something based on PRAGMA, knowing that your DB is “main”
db eval { PRAGMA main.table_info(<your table name>) } TBL { puts $TBL(name) }
And array use to obtain a list
set col_list {}
db eval { PRAGMA main.table_info(<your table name>) } TBL { lappend col_list $TBL(name) }
puts $col_list