I am writing a single query to insert data into 2 tables using "WITH AS". The query works fine on Postgres but on H2 database it is throwing syntax error.
I have 2 tables.
Table 1 has 2 columns -- a Primary Key table1_ID and a table1_value column.
Table 2 has 3 columns -- a PK table2_Id and table2_value and table1_id as Foreign key.
The query is like this:
WITH ins as (
INSERT INTO table_1 (table1_value) VALUES ("table1_value")
RETURNING table1_ID as t1_id
)
INSERT INTO table_2 (table2_value, tab1_id) VALUES ("table2_value", (SELECT t1_id FROM ins));
This query works fine on Postgres but on H2 DB it throws syntax error with a message
"; expected "(, WITH, SELECT, FROM"; SQL statement
hadatabase reference link:
http://www.h2database.com/html/advanced.html#recursive_queries
http://www.h2database.com/html/commands.html?highlight=insert&search=insert#firstFound
see Compatibility section: https://www.postgresql.org/docs/current/sql-insert.html
INSERT conforms to the SQL standard, except that the RETURNING clause
is a PostgreSQL extension, as is the ability to use WITH with INSERT,
and the ability to specify an alternative action with ON CONFLICT.
Also, the case in which a column name list is omitted, but not all the
columns are filled from the VALUES clause or query, is disallowed by
the standard.
Related
I want to insert a new record if the record is not present in the table
For that I am using below query in Teradata
INSERT INTO sample(id, name) VALUES('12','rao')
WHERE NOT EXISTS (SELECT id FROM sample WHERE id = '12');
When I execute the above query I am getting below error.
WHERE NOT EXISTS
Failure 3706 Syntax error: expected something between ')' and the 'WHERE' keyword.
Can anyone help with the above issue. It will be very helpful.
You can use INSERT INTO ... SELECT ... as follows:
INSERT INTO sample(id,name)
select '12','rao'
WHERE NOT EXISTS (SELECT id FROM sample WHERE id = '12');
You can also create the primary/unique key on id column to avoid inserting duplicate data in id column.
I would advise writing the query as:
INSERT INTO sample (id, name)
SELECT id, name
FROM (SELECT 12 as id, 'rao' as name) x
WHERE NOT EXISTS (SELECT 1 FROM sample s WHERE s.id = x.id);
This means that you do not need to repeat the constant value -- such repetition can be a cause of errors in queries. Note that I removed the single quotes. id looks like a number so treat it as a number.
The uniqueness of ids is usually handled using a unique constraint or index:
alter table sample add constraint unq_sample_id unique (id);
This makes sure that the database ensures uniqueness. Your approach can fail if two inserts are run at the same time with the same id. An attempt to insert a duplicates returns an error (which the exists can then avoid).
In practice, id columns are usually generated automatically by the database. So the create table statement would look more like:
id integer generated by default as identity
And the insert would look like:
insert into sample (name)
values (name);
If id is the Primary Index of the table you can use MERGE:
merge into sample as tgt
using VALUES('12','rao') as src (id, name)
on src.id = tgt.id
when not matched
then insert (src.id,src.name)
I am trying to insert rows into an Oracle 19c table that we recently added a GENERATED ALWAYS AS IDENTITY column (column name is "ID"). The column should auto-increment and not need to be specified explicitly in an INSERT statement. Typical INSERT statements work - i.e. INSERT INTO table_name (field1,field2) VALUES ('f1', 'f2'). (merely an example). The ID field increments when typical INSERT is executed. But the query below, that was working before the addition of the IDENTITY COLUMN, is now not working and returning the error: ORA-00947: not enough values.
The field counts are identical with the exception of not including the new ID IDENTITY field, which I am expecting to auto-increment. Is this statement not allowed with an IDENTITY column?
Is the INSERT INTO statement, using a SELECT from another table, not allowing this and producing the error?
INSERT INTO T.AUDIT
(SELECT r.IDENTIFIER, r.SERIAL, r.NODE, r.NODEALIAS, r.MANAGER, r.AGENT, r.ALERTGROUP,
r.ALERTKEY, r.SEVERITY, r.SUMMARY, r.LASTMODIFIED, r.FIRSTOCCURRENCE, r.LASTOCCURRENCE,
r.POLL, r.TYPE, r.TALLY, r.CLASS, r.LOCATION, r.OWNERUID, r.OWNERGID, r.ACKNOWLEDGED,
r.EVENTID, r.DELETEDAT, r.ORIGINALSEVERITY, r.CATEGORY, r.SITEID, r.SITENAME, r.DURATION,
r.ACTIVECLEARCHANGE, r.NETWORK, r.EXTENDEDATTR, r.SERVERNAME, r.SERVERSERIAL, r.PROBESUBSECONDID
FROM R.STATUS r
JOIN
(SELECT SERVERSERIAL, MAX(LASTOCCURRENCE) as maxlast
FROM T.AUDIT
GROUP BY SERVERSERIAL) gla
ON r.SERVERSERIAL = gla.SERVERSERIAL
WHERE (r.LASTOCCURRENCE > SYSDATE - (1/1440)*5 AND gla.maxlast < r.LASTOCCURRENCE)
) )
Thanks for any help.
Yes, it does; your example insert
INSERT INTO table_name (field1,field2) VALUES ('f1', 'f2')
would also work as
INSERT INTO table_name (field1,field2) SELECT 'f1', 'f2' FROM DUAL
db<>fiddle demo
Your problematic real insert statement is not specifying the target column list, so when it used to work it was relying on the columns in the table (and their data types) matching the results of the query. (This is similar to relying on select *, and potentially problematic for some of the same reasons.)
Your query selects 34 values, so your table had 34 columns. You have now added a 35th column to the table, your new ID column. You know that you don't want to insert directly into that column, but in general Oracle doesn't, at least at the point it's comparing the query with the table columns. The table has 35 columns, so as you haven't said otherwise as part of the statement, it is expecting 35 values in the select list.
There's no way for Oracle to know which of the 35 columns you're skipping. Arguably it could guess based on the identity column, but that would be more work and inconsistent, and it's not unreasonable for it to insist you do the work to make sure it's right. It's expecting 35 values, it sees 34, so it throws an error saying there are not enough values - which is true.
Your question sort of implies you think Oracle might be doing something special to prevent the insert ... select ... syntax if there is an identity column, but in facts it's the opposite - it isn't doing anything special, and it's reporting the column/value count mismatch as it usually would.
So, you have to list the columns you are populating - you can't automatically skip one. So you statement needs to be:
INSERT INTO T.AUDIT (IDENTIFIER, SERIAL, NODE, ..., PROBESUBSECONDID)
SELECT r.IDENTIFIER, r.SERIAL, r.NODE, ..., r.PROBESUBSECONDID
FROM ...
using the actual column names of course if they differ from the query column names.
If you can't change that insert statement then you could make the ID column invisible; but then you would have to specify it explicitly in queries, as select * won't see it - but then you shouldn't rely on * anyway.
db<>fiddle
I have a table with ID primary key (autoincrement) and a unique column Name. Is there an efficient way in MariaDB to insert a row into this table if the same Name doesn't exist, otherwise select the existing row and, in both cases, return the ID of the row with this Name?
Here's a solution for Postgres. However, it seems MariaDB doesn't have the RETURNING id clause.
What I have tried so far is brute-force:
INSERT IGNORE INTO services (Name) VALUES ('JohnDoe');
SELECT ID FROM services WHERE Name='JohnDoe';
UPDATE: MariaDB 10.5 has RETURNING clause, however, the queries I have tried so far throw a syntax error:
WITH i AS (INSERT IGNORE INTO services (`Name`) VALUES ('John') RETURNING ID)
SELECT ID FROM i
UNION
SELECT ID FROM services WHERE `Name`='John'
For a single row, assuming id is AUTO_INCREMENT.
INSERT INTO t (name)
VALUES ('JohnDoe')
ON DUPLICATE KEY id = LAST_INSERT_ID(id);
SELECT LAST_INSERT_ID();
That looks kludgy, but it is an example in the documentation.
Caution: Most forms of INSERT will "burn" auto_inc ids. That is, they grab the next id(s) before realizing that the id won't be used. This could lead to overflowing the max auto_inc size.
It is also wise not to put the normalization inside the transaction that does the "meat" of the code. It ties up the table unnecessarily long and runs extra risk of burning ids in the case of rollback.
For batch updating of a 'normalization' table like that, see my notes here: http://mysql.rjweb.org/doc.php/staging_table#normalization (It avoids burning ids.)
In Table A i have many fields like referenceid, amount, timestamp, remarks, status, balancebefore, balanceafter, frmsisdn, tomsisdn, id etc etc
I want to create a new table, Table B based of Table A(with column names, datatypes etc etc) but i only need specific columns that are in table A.
I tried select * into TableB from TableA where 1 = 2 but it says ORA-00905: missing keyword. I am using TOAD.
thank you
In Oracle, the correct syntax is create table as. SELECT INTO is used primarily in SQL Server and Sybase.
create table tableb as
select . . .
from tableA;
Only include the where clause if you don't actually want to insert any rows.
In MySQL the syntax is the same as Oracle's (see here).
Notice that the new table does not contain any constraints from the original table (indexes, keys, etc.)
We're using Oracle 11g at the moment without Enterprise (not an option unfortunately).
Let's say I have a table with a constant(Let's say 2000) rows of data. Let's call it data_source.
I want to insert some columns of this table into another table, data_dest. I'm using all the records from the source table.
In other words, I would like to insert this set
select data_source.col1, data_source.col2, ... data_source.colN
from data_source
Which would be faster in this case:
insert into data_dest
select data_source.col1, data_source.col2, ... data_source.colN
from data_source
OR
merge into data_dest dd
using data_source ds
on (dd.col1 = ds.col1) --Let's assume that this is a matching column names
when not matched
insert (col1,col2...)
values(ds.col1,ds.col2...)
EDIT 1:
We can assume there are no primary keys violations from the insert.
In other words we can assume that insert will successfully insert all of the rows and so will merge.
The insert is very likely faster because it does not require a join on the two tables.
That said, the two queries are not equivalent. Assuming that col1 is defined as the primary key, the insert will throw an error if data_source contains a value in col1 that is already in data_dest. Because the merge is comparing the data in the two tables, then only inserting only the rows that don't already exist, it won't ever throw a primary key violation.
An insert that would be equivalent to the merge would be:
INSERT INTO data_dest
SELECT data_source.col1, data_source.col2, ... data_source.colN
FROM data_source
WHERE NOT EXISTS
(SELECT *
FROM data_dest
WHERE data_source.col1 = data_dest.col1)
It's likely that the plan for this insert will be very similar (if not identical) to the plan for the merge and the performance would be indistinguishable.