I want to INSERT OR REPLACE a row specified by 'uuid' column value. There is what I have:
INSERT OR REPLACE INTO feature_layer (id, uuid, feature_collection)
VALUES ((SELECT id FROM feature_layer WHERE uuid=?) , ?, GeomFromGeoJSON(?));
Will this query do what I want, which means update row specified by uuid or insert new one if no such row is present?
Assuming that your id field is defined as (with AUTOINCREMENT)
id INTEGER PRIMARY KEY AUTOINCREMENT
the correct statement will be
INSERT OR REPLACE INTO feature_layer (id, uuid, feature_collection)
VALUES ((SELECT id FROM feature_layer WHERE uuid=?), ?, GeomFromGeoJSON(?));
(you missed one ( in your query)
If your id field is defined as (without AUTOINCREMENT)
id INTEGER PRIMARY KEY
you will want to use COALESCE to set a new id (I have added one ? for the new id) if no records are found:
INSERT OR REPLACE INTO feature_layer (id, uuid, feature_collection)
VALUES (COALESCE((SELECT id FROM feature_layer WHERE uuid=?),?) , ?, GeomFromGeoJSON(?));
With the above queries, as you want, you will update uuid and feature_collection when the id matches the one filtered by uuid, and if no records are found, then it will insert a new record with your desired values for uuid and feature_collection.
Anyway, take into account that your id field must be the PRIMARY KEY to use this method.
Related
I have below two tables. I wrote after insert trigger on employees table. If i insert the record in employees table it will insert the record in employee_audits table.
Both table have primary key column (id). suppose if you try to insert record ID value which does not exists in employees table and exists in employee_audits table, it shows the
error duplicate key value violates unique constraint "employee_audits_pkey" and also it is not inserting record in employees table. Both transaction failed.
But i want to insert the record in employees table.
CREATE TABLE employees(
id SERIAL PRIMARY KEY,
first_name VARCHAR(40) NOT NULL,
last_name VARCHAR(40) NOT NULL
);
CREATE TABLE employee_audits (
id SERIAL PRIMARY KEY,
last_name VARCHAR(40) NOT NULL,
changed_on TIMESTAMP(6) NOT NULL
)
The trigger function:
CREATE OR REPLACE FUNCTION log_last_name_changes()
RETURNS trigger AS
$BODY$
BEGIN
INSERT INTO employee_audits(last_name,changed_on)
VALUES(NEW.last_name,now());
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
The trigger definition:
CREATE TRIGGER last_name_changes
AFTER INSERT
ON employees
FOR EACH ROW
EXECUTE PROCEDURE log_last_name_changes();
INSERT INTO employees (first_name, last_name)
VALUES ('John', 'Doe');
SELECT * FROM EMPLOYEES
id first_name last_name
1 "John" "Doe"
SELECT * FROM EMPLOYEE_AUDITS
ID last_name CHANGED_ON
1 "Doe" "2019-12-27 17:21:13.934"
Manual insert on second table
insert into employee_audits values(2,'banu','2019-12-27 17:21:13.934')
Manual insert on first table
INSERT INTO employees (first_name, last_name)
VALUES ('David', 'Raj');
Error duplicate key value violates unique constraint "employee_audits_pkey"
is it possible to insert record in employees table?
If you have a serial column you should never provide the value for it manually. Manually providing a value for a serial will not advance the sequence behind that column, so the next time you insert without specifying the id column, the next sequence value will be taken which is 2 as the sequence was only advanced once.
So instead of:
insert into employee_audits values(2,'banu','2019-12-27 17:21:13.934')
Just use:
insert into employee_audits (last_name, changed_at)
values ('banu','2019-12-27 17:21:13.934');
This behaviour of the serial columns is one of the reasons why it's highly recommended to use identity columns with modern Postgres versions.
If I have a non-integer primary-key the rowid is an auto-increment starting at 1.
sqlite> create table t1 (name text, documentid integer, primary key (name));
sqlite> insert into t1 (name, documentid) values ('max', 123);
sqlite> insert into t1 (name, documentid) values ('duf', 321);
sqlite> select rowid,* from t1;
1|max|123
2|duf|321
But if I have a INTEGER primary-key it seems the rowid is equal to it.
sqlite> create table t2 (name text, xid integer, primary key (xid));
sqlite> insert into t2 (name, xid) values ('max', 123);
sqlite> insert into t2 (name, xid) values ('duf', 321);
sqlite> select rowid,* from t2;
123|max|123
321|duf|321
Thats unexpected for me. I would expect rowid to behave like in the 1st sample.
Is that normal behaviour? Can I make it work like expected?
I am using SqlLite3 3.27
The problem is not the value as long it is uniqua (must be by definition of primary). But in JDBC I can not address ResultSet.getInt ("rowid") anymore - need to use getInt ("xid") instead" to make it work. Thats abnormal to a table with a non-integer primar-key.
An INTEGER PRIMARY KEY column is just an alias for the rowid. It acts the same (Having a value automatically assigned if left out when inserting a row), and doesn't even take up any extra space in the database. You can reference the column via its name, rowid, or any of the other standard aliases for rowid like oid.
From the documentation:
With one exception noted below, if a rowid table has a primary key that consists of a single column and the declared type of that column is "INTEGER" in any mixture of upper and lower case, then the column becomes an alias for the rowid. Such a column is usually referred to as an "integer primary key". A PRIMARY KEY column only becomes an integer primary key if the declared type name is exactly "INTEGER". Other integer type names like "INT" or "BIGINT" or "SHORT INTEGER" or "UNSIGNED INTEGER" causes the primary key column to behave as an ordinary table column with integer affinity and a unique index, not as an alias for the rowid.
If you just do
INSERT INTO t2(name) VALUES ('max');
a value will be automatically generated for xid instead of explicitly using the one provided in the insert like in your example.
Yes it's the normal behavior.
When you define an integer column xid as primary key, then xid is just an alias of rowid.
What you can do is define xid as UNIQUE and not PRIMARY KEY:
create table t2 (name text, xid integer unique)
Then you will have the functionality that you want, because the rowid will be a different auto increment column.
Or define xid as TEXT:
create table t2 (name text, xid text, primary key (xid));
In this case also rowid is a different column and don't worry about the data you store in xid.
You can treat this column just like an integer column so you can perform any arithmetic calculation and aggregation.
You can find more here: https://www.sqlite.org/rowidtable.html
I need to copy one table to another and both tables contain column with AUTOINCREMENT. Is it possible to insert a defined value into AUTOINCREMENT column.
Tables:
CREATE TABLE tmptimetables (
_id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
_title NVARCHAR(256) NOT NULL,
_weeks INTEGER NOT NULL,
_first_week_date INTEGER NOT NULL,
_auto_complete INTEGER NOT NULL,
_first_lesson_time INTEGER NOT NULL,
_lesson_duration INTEGER NOT NULL,
_break_duration INTEGER NOT NULL,
_color INTEGER NOT NULL,
_symbol NCHAR(1) NOT NULL
);
CREATE TABLE timetables (
id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
title NVARCHAR(256) NOT NULL,
weeks INTEGER NOT NULL,
first_week_date INTEGER NOT NULL,
auto_complete INTEGER NOT NULL,
first_lesson_time INTEGER NOT NULL,
lesson_duration INTEGER NOT NULL,
break_duration INTEGER NOT NULL,
color INTEGER NOT NULL,
symbol NCHAR(1) NOT NULL
);
My SQL request:
INSERT INTO timetables (
auto_complete,
break_duration,
color,
first_lesson_time,
first_week_date, id,
lesson_duration,
symbol,
title,
weeks
)
SELECT
_auto_complete,
_break_duration,
_color,
_first_lesson_time,
_first_week_date,
_id,
_lesson_duration,
_symbol,
_title,
_weeks
FROM tmptimetables
AUTOINCREMENT can only be used for a column that is INTEGER PRIMARY KEY, it is INTEGER PRIMARY KEY that is the factor that makes the column a special column whereby if the value is not provided when inserting a row that a unique integer will be assigned.
So be the column INTEGER PRIMARY KEY or INTEGER PRIMARY KEY AUTOINCREMENT you can specify an integer value and a row may be inserted with the given value.
A row will not be inserted with a given value if that value is not unique.
For example if the table timetables is currently :-
Then
INSERT INTO timetables (id,title,weeks,first_week_date,auto_complete,first_lesson_time,lesson_duration,break_duration,color,symbol) VALUES (null,'mytitle',78,86000,23,1800,900,200,16,'E');
Would insert a new row with the id as determined by SQLite's algorithm for providing a unique id (probably 5).
If the id were changed to be provided (i.e. not null) say to 10 as per :-
INSERT INTO timetables (id,title,weeks,first_week_date,auto_complete,first_lesson_time,lesson_duration,break_duration,color,symbol) VALUES (10,'mytitle',78,86000,23,1800,900,200,16,'E');
Then the id for the new row would be 10.
However if then using (the same SQL but with the last column value changed) :-
INSERT INTO timetables (id,title,weeks,first_week_date,auto_complete,first_lesson_time,lesson_duration,break_duration,color,symbol) VALUES (10,'mytitle',78,86000,23,1800,900,200,16,'Z');
A new row would not be inserted as a row with an id of 10 already exists.
Finally if the id is not given (null is used) but the SQL is otherwise the same a new row is inserted with a unique id being provided by SQLite e.g.
INSERT INTO timetables (id,title,weeks,first_week_date,auto_complete,first_lesson_time,lesson_duration,break_duration,color,symbol) VALUES (null,'mytitle',78,86000,23,1800,900,200,16,'Z');
So the end result of following the above is :-
AUTOINCREMENT
The AUTOINCREMENT keyword, only usable for an INTEGER PRIMARY COLUMN, invokes a different algorithm for determining the next sequence to ensure that the next sequence/id is always greater, whilst without AUTOINCREMENT a lower sequence/id can be applied.
The AUTOINCREMENT keyword does not specify that if a value for the column is not provided then a sequence/id is applied it is INTEGER PRIMARY KEY that specifies that. Well actually, by default, i.e. unless WITHOUT ROWID is specified, this happens for all tables. It's just the the special rowid column is hidden. Specifying <column_name> INTEGER PRIMARY KEY (where is a valid column name) creates an alias of the rowid.
For example using SELECT rowid,* FROM timetables produces :-
SQLite Autoincrement
Rowid Tables
CREATE TABLE resource_sync
(
_id INTEGER UNIQUE ON CONFLICT REPLACE PRIMARY KEY,
status_id INTEGER,
result_id INTEGER
);
In case two equal _id values get inserted, SQLite would throw an exception:
[13:39:48] Error while executing SQL query on database 'test': UNIQUE
constraint failed: resource_sync._id
However, it allows for desired replaces in case primary key declaration is removed from table creation SQL.
Why is that?
Thanks.
UNIQUE is ignored on primary keys.
The correct syntax, as shown in the documentation, is:
CREATE TABLE resource_sync
(
_id INTEGER PRIMARY KEY ON CONFLICT REPLACE,
status_id INTEGER,
result_id INTEGER
);
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.