Does anyone know how to prepend leading zeros to a column in sqlite?
I am getting columns like 1, 2 and for our data import they need to be 3 character codes with leading zeros.
I've tried this
update LockBox
set CustomField2 = case
when CustomField2 = '1' then '001'
end
WHERE CustomField2 = '1';
but does not give me the correct result. I'm probably doing this wrong. I'm more of a sql server guy not a sqlite person
I would do this in SQL Server
SELECT RIGHT('000'+CAST(field AS VARCHAR(3)),3)
How can I accomplish this in SQLite. I want to update the table then export to CSV to import into our business application.
Use substr:
update LockBox
set CustomField2 = substr('000' || CustomField2, -3, 3);
provided that all values in CustomField2 are no longer than 3 digits.
Define the column as text?
$ sqlite3 types
sqlite> create table T( i integer, c text );
sqlite> insert into T values ( '001', '001' );
sqlite> select * from T;
i c
---------- ----------
1 001
Related
I would like to repeat this command as many times as there is still sometextin the field note (several rows from the table itemNotes could have one or more sometext in the field note):
UPDATE itemNotes
SET
note = SUBSTR(note, 0, INSTR(LOWER(note), 'sometext')) || 'abc' || SUBSTR(note, INSTR(LOWER(note), 'sometext')+sometext_len)
WHERE
INSTR(LOWER(note), 'sometext') >= 0;
So a proto-code would be :
While (SELECT * FROM itemNotes WHERE note like "%sometext%") >1
UPDATE itemNotes
SET
note = SUBSTR(note, 0, INSTR(LOWER(note), 'sometext')) || 'abc' || SUBSTR(note, INSTR(LOWER(note), 'sometext')+sometext_len)
WHERE
INSTR(LOWER(note), 'sometext') >= 0;
END
But apparently Sqlite3 doesn't support While loop or for loop. They can be emulated with something like this but I have difficulties integrating what I want with this query:
WITH b(x,y) AS
(
SELECT 1,2
UNION ALL
SELECT x+ 1, y + 1
FROM b
WHERE x < 20
) SELECT * FROM b;
Any idea how to do this?
PS: I don't use replace because I want to replace all the case combinations of sometext (e.g. sometext, SOMEtext, SOmeText...) cf this question
Current input and desired output:
For a single row, a note field could look like (and many rows in the table itemNotescould look like this one):
There is SOmetext and also somETExt and more SOMETEXT and even more sometext
The query should output:
There is abc and also abc and more abc and even more abc
I am doing it on the zotero.sqlite, which is created by this file (line 85). The table is created by this query
CREATE TABLE itemNotes (
itemID INTEGER PRIMARY KEY,
parentItemID INT,
note TEXT,
title TEXT,
FOREIGN KEY (itemID) REFERENCES items(itemID) ON DELETE CASCADE,
FOREIGN KEY (parentItemID) REFERENCES items(itemID) ON DELETE CASCADE
);
You just have your answer in your query:
UPDATE itemNotes
SET
note = SUBSTR(note, 0, INSTR(LOWER(note), 'sometext')) || 'abc' || SUBSTR(note, INSTR(LOWER(note), 'sometext')+sometext_len)
WHERE
note LIKE "%sometext%";
It will update all rows that contain sometext in the note field
UPDATE
If you want to update the field which has multiple occurrences in different cases and maintain the rest of the text the simplest solution imo is to use regex and for that you need an extension
UPDATE itemNotes
SET
note = regex_replace('\bsometext\b',note,'abc')
WHERE
note LIKE "%sometext%";
As recommended by Stephan in his last comment, I used python to do this.
Here is my code :
import sqlite3
import re
keyword = "sometext"
replacement = "abc"
db = sqlite3.connect(path_to_sqlite)
cursor = db.cursor()
cursor.execute(f'SELECT * FROM itemNotes WHERE note like "%{keyword}%"')
for row in cursor.fetchall():
row_regex = re.compile(re.escape(keyword), re.IGNORECASE)
row_regex_replaced = row_regex.sub(replacement, row[2])
rowID = row[0]
sql = "REPLACE INTO itemNotes (itemID,note) VALUES (?,?)"
data = (rowID, row_regex_replaced)
cursor.execute(sql, data)
db.commit()
I have a table like this
CREATE TABLE "modules" ( `ID` INTEGER PRIMARY KEY AUTOINCREMENT, `name` TEXT, `version` TEXT, `deployID` INTEGER )
I want to be able to get all the rows from this database where the version is different between different deploy ID's. So, say I have a deploy ID 2 and a deployID 3 - my table might have 2000 odd modules for each of these deploys. I want to only get the rows where the name is the same but the version is different. Is this possible? I thought this query would do it but it seems to be returning me everything - twice!
SELECT a.* FROM modules a
INNER JOIN modules b
ON a.name == b.name
WHERE a.version != b.version
AND a.deployID = 3
AND b.deployID = 2
If you only care about deployids 2 and 3:
select m.*
from modules m
where
m.deployid in (2, 3)
and
exists (
select 1 from modules
where
name = m.name
and
deployID <> m.deployID
and
version <> m.version
)
If you don't need this condition:
deployID <> m.deployID
you can remove it.
I would probably use an exists query here:
SELECT m1.*
FROM modules m1
WHERE EXISTS (SELECT 1 FROM modules m2
WHERE m1.name = m2.name AND
m1.deployID <> m2.deployID AND m1.version <> m2.version);
Or maybe you want a more specific version:
SELECT m1.*
FROM modules m1
WHERE EXISTS (SELECT 1 FROM modules m2
WHERE m1.name = m2.name AND
LEAST(m1.deployID, m2.deployID) = 2 AND
GREATEST(m1.deployID, m2.deployID) = 3);
ALTER PROCEDURE [dbo].[K_FS_InsertMrpDetails]
#date datetime,
#feedtype varchar(50),
#rateperkg float,
#rateper50kg float,
#updatedby varchar(50)
AS
BEGIN
INSERT INTO K_FS_FeedMrpDetails([date], feedtype, rateperkg, rateper50kg, updatedby, updatedon)
VALUES(#date, #feedtype, #rateperkg, #rateper50kg, #updatedby, getdate())
SELECT '1' AS status
END
With this query we insert 9 rows at a time but what I want is in one same date do not insert again different details. How can I please help me.
Add a unique constraint on the column [date]. That will prevent you from adding more than one row with the same [date] value.
Update:
To allow 9 rows for each date you can add a computed column D that removes the time part and you need to add a column that will hold the values 1 to 9 R. Use a check constraint on R to only allow 1-9. Finally you create a unique constraint on (R, D).
Sample table definition:
create table T
(
ID int identity primary key,
DT datetime not null,
R tinyint check (R in (1,2,3,4,5,6,7,8,9)) not null,
D as dateadd(day, datediff(day, 0, DT), 0),
constraint ux_RD unique (R,D)
)
Try with this:
insert into T(DT, R) values(getdate(), 1)
insert into T(DT, R) values(getdate(), 2)
insert into T(DT, R) values(getdate(), 1)
First and second insert works fine, the third raises a unique constraint exception.
I can not figure out how to query a SQLite.
needed:
1) Replace the record (the primary key), if the condition (comparison of new and old fields entries)
2) Insert an entry if no such entry exists in the database on the primary key.
Importantly, it has to work very fast!
I can not come up with an effective inquiry.
Edit.
MyInsertRequest - the desired expression.
Script:
CREATE TABLE testtable (a INT PRIMARY KEY, b INT, c INT)
INSERT INTO testtable VALUES (1, 2, 3)
select * from testtable
1|2|3
-- Adds an entry, because the primary key is not
++ MyInsertRequest VALUES (2, 2, 3) {if c>4 then replace}
select * from testtable
1|2|3
2|2|3
-- Adds
++ MyInsertRequest VALUES (3, 8, 3) {if c>4 then replace}
select * from testtable
1|2|3
2|2|3
3|8|3
-- Does nothing, because such a record (from primary key field 'a')
-- is in the database and none c>4
++ MyInsertRequest VALUES (1, 2, 3) {if c>4 then replace}
select * from testtable
1|2|3
2|2|3
3|8|3
-- Does nothing
++ MyInsertRequest VALUES (3, 34, 3) {if c>4 then replace}
select * from testtable
1|2|3
2|2|3
3|8|3
-- replace, because such a record (from primary key field 'a')
-- is in the database and c>2
++ MyInsertRequest VALUES (3, 34, 1) {if c>2 then replace}
select * from testtable
1|2|3
2|2|3
3|34|1
Isn't INSERT OR REPLACE what you need ? e.g. :
INSERT OR REPLACE INTO table (cola, colb) values (valuea, valueb)
When a UNIQUE constraint violation occurs, the REPLACE algorithm
deletes pre-existing rows that are causing the constraint violation
prior to inserting or updating the current row and the command
continues executing normally.
You have to put the condition in a unique constraint on the table. It will automatically create an index to make the check efficient.
e.g.
-- here the condition is on columnA, columnB
CREATE TABLE sometable (columnPK INT PRIMARY KEY,
columnA INT,
columnB INT,
columnC INT,
CONSTRAINT constname UNIQUE (columnA, columnB)
)
INSERT INTO sometable VALUES (1, 1, 1, 0);
INSERT INTO sometable VALUES (2, 1, 2, 0);
select * from sometable
1|1|1|0
2|1|2|0
-- insert a line with a new PK, but with existing values for (columnA, columnB)
-- the line with PK 2 will be replaced
INSERT OR REPLACE INTO sometable VALUES (12, 1, 2, 6)
select * from sometable
1|1|1|0
12|1|2|6
Assuming your requirements are:
Insert a new row when a doesn't exists;
Replacing row when a exist and existing c greater then new c;
Do nothing when a exist and existing c lesser or equal then new c;
INSERT OR REPLACE fits first two requirements.
For last requirement, the only way I know to make an INSERT ineffective is supplying a empty rowset.
A SQLite command like following whould make the job:
INSERT OR REPLACE INTO sometable SELECT newdata.* FROM
(SELECT 3 AS a, 2 AS b, 1 AS c) AS newdata
LEFT JOIN sometable ON newdata.a=sometable.a
WHERE newdata.c<sometable.c OR sometable.a IS NULL;
New data (3,2,1 in this example) is LEFT JOINen with current table data.
Then WHERE will "de-select" the row when new c is not less then existing c, keeping it when row is new, ie, sometable.* IS NULL.
I tried the others answers because I was also suffering from a solution to this problem.
This should work, however I am unsure about the performance implications. I believe that you may need the first column to be unique as a primary key else it will simply insert a new record each time.
INSERT OR REPLACE INTO sometable
SELECT columnA, columnB, columnC FROM (
SELECT columnA, columnB, columnC, 1 AS tmp FROM sometable
WHERE sometable.columnA = 1 AND
sometable.columnB > 9
UNION
SELECT 1 AS columnA, 1 As columnB, 404 as columnC, 0 AS tmp)
ORDER BY tmp DESC
LIMIT 1
In this case one dummy query is executed and union-ed onto a second query which would have a performance impact depending on how it is written and how the table is indexed. The next performance problem has potential where the results are ordered and limited. However, I expect that the second query should only return one record and therefore it should not be too much of a performance hit.
You can also omit the ORDER BY tmp LIMIT 1 and it works with my version of sqlite, but it may impact performance since it can end up updating the record twice (writing the original value then the new value if applicable).
The other problem is that you end up with a write to the table even if the condition states that it should not be updated.
I'm adding an 'index' column to a table in SQLite3 to allow the users to easily reorder the data, by renaming the old database and creating a new one in its place with the extra columns.
The problem I have is that I need to give each row a unique number in the 'index' column when I INSERT...SELECT the old values.
A search I did turned up a useful term in Oracle called ROWNUM, but SQLite3 doesn't have that. Is there something equivalent in SQLite?
You can use one of the special row names ROWID, OID or _ROWID_ to get the rowid of a column. See http://www.sqlite.org/lang_createtable.html#rowid for further details (and that the rows can be hidden by normal columns called ROWID and so on).
Many people here seems to mix up ROWNUM with ROWID. They are not the same concept and Oracle has both.
ROWID is a unique ID of a database ROW. It's almost invariant (changed during import/export but it is the same across different SQL queries).
ROWNUM is a calculated field corresponding to the row number in the query result. It's always 1 for the first row, 2 for the second, and so on. It is absolutely not linked to any table row and the same table row could have very different rownums depending of how it is queried.
Sqlite has a ROWID but no ROWNUM. The only equivalent I found is ROW_NUMBER() function (see http://www.sqlitetutorial.net/sqlite-window-functions/sqlite-row_number/).
You can achieve what you want with a query like this:
insert into new
select *, row_number() over ()
from old;
No SQLite doesn't have a direct equivalent to Oracle's ROWNUM.
If I understand your requirement correctly, you should be able to add a numbered column based on ordering of the old table this way:
create table old (col1, col2);
insert into old values
('d', 3),
('s', 3),
('d', 1),
('w', 45),
('b', 5465),
('w', 3),
('b', 23);
create table new (colPK INTEGER PRIMARY KEY AUTOINCREMENT, col1, col2);
insert into new select NULL, col1, col2 from old order by col1, col2;
The new table contains:
.headers on
.mode column
select * from new;
colPK col1 col2
---------- ---------- ----------
1 b 23
2 b 5465
3 d 1
4 d 3
5 s 3
6 w 3
7 w 45
The AUTOINCREMENT does what its name suggests: each additional row has the previous' value incremented by 1.
I believe you want to use the constrain LIMIT in SQLite.
SELECT * FROM TABLE can return thousands of records.
However, you can constrain this by adding the LIMIT keyword.
SELECT * FROM TABLE LIMIT 5;
Will return the first 5 records from the table returned in you query - if available
use this code For create Row_num 0....count_row
SELECT (SELECT COUNT(*)
FROM main AS t2
WHERE t2.col1 < t1.col1) + (SELECT COUNT(*)
FROM main AS t3
WHERE t3.col1 = t1.col1 AND t3.col1 < t1.col1) AS rowNum, * FROM Table_name t1 WHERE rowNum=0 ORDER BY t1.col1 ASC