I'm trying to add a test user to my website that employers can look at to see my work. I want to use some of the data I have entered into my profile so that it is faster.
I have a workouts table:
CREATE TABLE workouts(
id INTEGER NOT NULL,
userID INTEGER NOT NULL,
DateAndTime smalldatetime NOT NULL,
PRIMARY KEY (id),
FOREIGN KEY (UserID) REFERENCES users(id)
);
I have taken 25 of the first results and put it into a temporary workouts2 table:
CREATE TABLE workouts2 (
userid integer,
dateandtime smalldatetime);
Now I want to take those rows from workouts2 and put them into workouts. I have tried to add them by inserting workouts2 into workouts like this:
insert into workouts (id , userID, DateandTime) values (select * from workouts2);
This gives me an Error: in prepare, near "select": syntax error (1)
I can do it one at a time like this:
insert into workouts (userid, dateandtime) values (2, "2022-01-02T06:00");
Doing it one at a time is not ideal.
What am I missing here? I know I have a syntax error but I don't know how to fix it.
I have looked at this question which inserts one at a time:
How to insert a unique ID into each SQLite row?
The problem is it only inserts one at a time.
You should use SELECT instead of VALUES and not include the column id, which is auto-incremented, in the list of columns of workouts which will receive the values (such a column does not exist in workouts2):
INSERT INTO workouts (userID, DateandTime)
SELECT *
FROM workouts2;
On the database open, I inserted 5 records into the Expense table. Then I removed all 5 records one by one.
And before I insert new entry I check max inserted id. For some reason it's null. What's wrong?
var result = await db.rawQuery("SELECT MAX(id) as last_inserted_id FROM Expense");
final maxID = result.first["last_inserted_id"];
print('maxID:$maxID'); //maxID:null
If there are no rows in the table, there is no maximum defined. What you rather should do is look for the ID sequence number of the table to find out what the next ID will be. That information is usually stored in some meta table of the DB.
SELECT seq FROM SQLITE_SEQUENCE WHERE name='Expense';
Hello i have an sqlite db with many records like 10540 record they are ordered by creation time , i want to shift like a record in the middle and like to do it automatically
for example :
select * from table1 where id >= 8521;
UPDATE Table1 SET id = id +1 ;
does not work i get Error: Result: UNIQUE constraint failed:
so i want to shift up all records from 8521 to the last record and get place in the 8520 place for example so i can insert my record in that place of table .
even the
id = select max(id)+1
does not work how can i increment the id from last record to the needed record so i can put a place in the records db
A simple update statement would fail, as it would try to create duplicate values in the primary key.
What you can do is this:
First update the column to the negatives of the values they should have:
update table1
set id = -(id + 1)
where id > 8520;
Now there are no duplicates and you just need to update again to the positive values:
update table1
set id = -id
where id < 0;
This will do the trick, but any kind of updating the primary key is not a recommended practice
I want to create a table with a field that is unique and limited to a certain value. Lets say that the limit is 100, the table is full, I remove a random row, and when I create a new row it has the value that was freed before.
It doesn't need to be the fastest thing in the world (the limit is quite small), I just want to implement it in a DB.
Any ideas?
Create one more column in main table, say deleted (integer, 0 or 1). When you need to delete with certain id, do not really delete it, but simply update deleted to 1:
UPDATE mytable SET deleted=1 WHERE id = <id_to_delete>
When you need to insert, find id to be reused:
SELECT id FROM mytable WHERE deleted LIMIT 1
If this query returns empty result, then use INSERT to create new id. Otherwise, simply update your row:
UPDATE mytable SET deleted=0, name='blah', ... WHERE id=<id_to_reuse>
All queries reading from your main table should have WHERE constraint with NOT deleted condition:
SELECT * FROM mytable WHERE NOT deleted
If you add index on deleted, this method should work fast even for large number of rows.
This solution does everything in a trigger, so you can just use a normal INSERT.
For the table itself, we use an autoincrementing ID column:
CREATE TABLE MyTable(ID INTEGER PRIMARY KEY, Name);
We need another table to store an ID temporarily:
CREATE TABLE moriturus(ID INTEGER PRIMARY KEY);
And the trigger:
CREATE TRIGGER MyTable_DeleteAndReorder
AFTER INSERT ON MyTable
FOR EACH ROW
WHEN (SELECT COUNT(*) FROM MyTable) > 100
BEGIN
-- first, select a random record to be deleted, and save its ID
DELETE FROM moriturus;
INSERT INTO moriturus
SELECT ID FROM MyTable
WHERE ID <> NEW.ID
ORDER BY random()
LIMIT 1;
-- then actually delete it
DELETE FROM MyTable
WHERE ID = (SELECT ID
FROM moriturus);
-- then change the just inserted record to have that ID
UPDATE MyTable
SET ID = (SELECT ID
FROM moriturus)
WHERE ID = NEW.ID;
END;
I've found a few "would be" solutions for the classic "How do I insert a new record or update one if it already exists" but I cannot get any of them to work in SQLite.
I have a table defined as follows:
CREATE TABLE Book
ID INTEGER PRIMARY KEY AUTOINCREMENT,
Name VARCHAR(60) UNIQUE,
TypeID INTEGER,
Level INTEGER,
Seen INTEGER
What I want to do is add a record with a unique Name. If the Name already exists, I want to modify the fields.
Can somebody tell me how to do this please?
Have a look at http://sqlite.org/lang_conflict.html.
You want something like:
insert or replace into Book (ID, Name, TypeID, Level, Seen) values
((select ID from Book where Name = "SearchName"), "SearchName", ...);
Note that any field not in the insert list will be set to NULL if the row already exists in the table. This is why there's a subselect for the ID column: In the replacement case the statement would set it to NULL and then a fresh ID would be allocated.
This approach can also be used if you want to leave particular field values alone if the row in the replacement case but set the field to NULL in the insert case.
For example, assuming you want to leave Seen alone:
insert or replace into Book (ID, Name, TypeID, Level, Seen) values (
(select ID from Book where Name = "SearchName"),
"SearchName",
5,
6,
(select Seen from Book where Name = "SearchName"));
You should use the INSERT OR IGNORE command followed by an UPDATE command:
In the following example name is a primary key:
INSERT OR IGNORE INTO my_table (name, age) VALUES ('Karen', 34)
UPDATE my_table SET age = 34 WHERE name='Karen'
The first command will insert the record. If the record exists, it will ignore the error caused by the conflict with an existing primary key.
The second command will update the record (which now definitely exists)
You need to set a constraint on the table to trigger a "conflict" which you then resolve by doing a replace:
CREATE TABLE data (id INTEGER PRIMARY KEY, event_id INTEGER, track_id INTEGER, value REAL);
CREATE UNIQUE INDEX data_idx ON data(event_id, track_id);
Then you can issue:
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 2, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 5);
The "SELECT * FROM data" will give you:
2|2|2|3.0
3|1|2|5.0
Note that the data.id is "3" and not "1" because REPLACE does a DELETE and INSERT, not an UPDATE. This also means that you must ensure that you define all necessary columns or you will get unexpected NULL values.
INSERT OR REPLACE will replace the other fields to default value.
sqlite> CREATE TABLE Book (
ID INTEGER PRIMARY KEY AUTOINCREMENT,
Name TEXT,
TypeID INTEGER,
Level INTEGER,
Seen INTEGER
);
sqlite> INSERT INTO Book VALUES (1001, 'C++', 10, 10, 0);
sqlite> SELECT * FROM Book;
1001|C++|10|10|0
sqlite> INSERT OR REPLACE INTO Book(ID, Name) VALUES(1001, 'SQLite');
sqlite> SELECT * FROM Book;
1001|SQLite|||
If you want to preserve the other field
Method 1
sqlite> SELECT * FROM Book;
1001|C++|10|10|0
sqlite> INSERT OR IGNORE INTO Book(ID) VALUES(1001);
sqlite> UPDATE Book SET Name='SQLite' WHERE ID=1001;
sqlite> SELECT * FROM Book;
1001|SQLite|10|10|0
Method 2
Using UPSERT (syntax was added to SQLite with version 3.24.0 (2018-06-04))
INSERT INTO Book (ID, Name)
VALUES (1001, 'SQLite')
ON CONFLICT (ID) DO
UPDATE SET Name=excluded.Name;
The excluded. prefix equal to the value in VALUES ('SQLite').
Firstly update it. If affected row count = 0 then insert it. Its the easiest and suitable for all RDBMS.
Upsert is what you want. UPSERT syntax was added to SQLite with version 3.24.0 (2018-06-04).
CREATE TABLE phonebook2(
name TEXT PRIMARY KEY,
phonenumber TEXT,
validDate DATE
);
INSERT INTO phonebook2(name,phonenumber,validDate)
VALUES('Alice','704-555-1212','2018-05-08')
ON CONFLICT(name) DO UPDATE SET
phonenumber=excluded.phonenumber,
validDate=excluded.validDate
WHERE excluded.validDate>phonebook2.validDate;
Be warned that at this point the actual word "UPSERT" is not part of the upsert syntax.
The correct syntax is
INSERT INTO ... ON CONFLICT(...) DO UPDATE SET...
and if you are doing INSERT INTO SELECT ... your select needs at least WHERE true to solve parser ambiguity about the token ON with the join syntax.
Be warned that INSERT OR REPLACE... will delete the record before inserting a new one if it has to replace, which could be bad if you have foreign key cascades or other delete triggers.
If you have no primary key, You can insert if not exist, then do an update. The table must contain at least one entry before using this.
INSERT INTO Test
(id, name)
SELECT
101 as id,
'Bob' as name
FROM Test
WHERE NOT EXISTS(SELECT * FROM Test WHERE id = 101 and name = 'Bob') LIMIT 1;
Update Test SET id='101' WHERE name='Bob';
I believe you want UPSERT.
"INSERT OR REPLACE" without the additional trickery in that answer will reset any fields you don't specify to NULL or other default value. (This behavior of INSERT OR REPLACE is unlike UPDATE; it's exactly like INSERT, because it actually is INSERT; however if what you wanted is UPDATE-if-exists you probably want the UPDATE semantics and will be unpleasantly surprised by the actual result.)
The trickery from the suggested UPSERT implementation is basically to use INSERT OR REPLACE, but specify all fields, using embedded SELECT clauses to retrieve the current value for fields you don't want to change.
I think it's worth pointing out that there can be some unexpected behaviour here if you don't thoroughly understand how PRIMARY KEY and UNIQUE interact.
As an example, if you want to insert a record only if the NAME field isn't currently taken, and if it is, you want a constraint exception to fire to tell you, then INSERT OR REPLACE will not throw and exception and instead will resolve the UNIQUE constraint itself by replacing the conflicting record (the existing record with the same NAME). Gaspard's demonstrates this really well in his answer above.
If you want a constraint exception to fire, you have to use an INSERT statement, and rely on a separate UPDATE command to update the record once you know the name isn't taken.