In DB2
SELECT id FROM FINAL TABLE (
INSERT INTO mytable (x,y,z) VALUES (1,2,3)
)
Works to give me back ANY data from the table / row inserted.
Is there an equivalent for this in MySQL? I'd like to avoid a transaction and two queries to do something that is possible in one.
Related
I have a table with many columns in SQL Server and I have move part of data into MySQL. I made a view or function on the table in SQL Server and these two databases must be synced once a day through job. Because the data of this view may change every day.
View return a table with 3 columns: (char, varchar, varchar) that none of them are unique or primary key.
My solution is:
create a job
execute view on SQL Server
return result of view
create temp table with 3 column in MySQL
move result view from SQL Server to temp table
move records from temp table to new table one by one if not exist before
delete temp table
To transfer without using the temp table, I wanted to use below type of query but could not find the correct query. That's why I used the temp table:
insert into new_table
values (array of records) where record if not exist in new table.
And for the solution I mentioned above, I used the following query:
insert into new_table
select *
from temp_table
where not exist new_table.column = temp_table.column
Do you have a better suggestion that new records can be fetch and added to previous records?
It should look more like this:
insert into new_table
select *
from temp_table
where not exists (
select 1
from new_table
where new_table.column = temp_table.column
)
or maybe this:
insert into new_table
select *
from temp_table
where not exists (
select 1
from new_table
where new_table.column = temp_table.column
and new_table.column2 = temp_table.column2
and new_table.column3 = temp_table.column3
)
I have two tables, Table1 contains a list of records with columns super_id, user_name and job_type
Table2 contains a 3 columns as well super_id, view and time
Using a select query with criteria on table I would like to create one record per super_id in Table2
Meaning if the select query was SELECT super_id FROM Table1 WHERE job_type = “Instructor”
RF34323 through RF34328 would appear would each be inserted once into Table2 where the View column is always View1 and time is the current date.
How can an Select Insert query like this written?
The following is an example of the 2 tables:
Is this what you want?
insert into table2 (super_id, `view`, `time`)
select super_id, 'view1', now()
from table1
where job_type = 'Instructor';
Note that view and time are very BAD choices for column names, because they are keywords in SQL.
If you want to create table2, then use create table table2 as instead of insert.
Also, you can default the time column to the insertion time, if you set up the table properly.
I have two tables ,location and locationdata. I want to query data from both the tables using join and to store the result in a new table(locationCreatedNew) which is not already present in the MySQL.Can I do this in MySQL?
SELECT location.id,locationdata.name INTO locationCreatedNew FROM
location RIGHT JOIN locationdata ON
location.id=locationdata.location_location_id;
Your sample code in OP is syntax in SQL Server, the counter part of that in MySQL is something like:
CREATE TABLE locationCreatedNew
SELECT * FROM location RIGHT JOIN locationdata
ON location.id=locationdata.location_location_id;
Referance: CREATE TABLE ... SELECT
For CREATE TABLE ... SELECT, the destination table does not preserve information about whether columns in the selected-from table are generated columns. The SELECT part of the statement cannot assign values to generated columns in the destination table.
Some conversion of data types might occur. For example, the AUTO_INCREMENT attribute is not preserved, and VARCHAR columns can become CHAR columns. Retrained attributes are NULL (or NOT NULL) and, for those columns that have them, CHARACTER SET, COLLATION, COMMENT, and the DEFAULT clause.
When creating a table with CREATE TABLE ... SELECT, make sure to alias any function calls or expressions in the query. If you do not, the CREATE statement might fail or result in undesirable column names.
CREATE TABLE newTbl
SELECT tbl1.clm, COUNT(tbl2.tbl1_id) AS number_of_recs_tbl2
FROM tbl1 LEFT JOIN tbl2 ON tbl1.id = tbl2.tbl1_id
GROUP BY tbl1.id;
NOTE: newTbl is the name of the new table you want to create. You can use SELECT * FROM othertable which is the query that returns the data the table should be created from.
You can also explicitly specify the data type for a column in the created table:
CREATE TABLE foo (a TINYINT NOT NULL) SELECT b+1 AS a FROM bar;
For CREATE TABLE ... SELECT, if IF NOT EXISTS is given and the target table exists, nothing is inserted into the destination table, and the statement is not logged.
To ensure that the binary log can be used to re-create the original tables, MySQL does not permit concurrent inserts during CREATE TABLE ... SELECT.
You cannot use FOR UPDATE as part of the SELECT in a statement such as CREATE TABLE new_table SELECT ... FROM old_table .... If you attempt to do so, the statement fails.
Please check it for more. Hope this help you.
Use Query like below.
create table new_tbl as
select col1, col2, col3 from old_tbl t1, old_tbl t2
where condition;
Consider two tables that have timestamp and data columns. I need to construct an SQL that does the following:
Insert data (unique timestamp and data column) in one table if timestamp value is not present in the table ("insert my data in table 1 for timestamp="12:00 1999-01-01" only if that timestamp is not present in table 1...)
Otherwise, insert very same data in different table without any checks, and overwrite if necessary (... otherwise insert same set of fields in table 2).
How I could possibly achieve this on SQL? I could do it using a client but this is way slower. I use MySQL
Run a query for your 2nd bullet first. i.e. insert data into table 2 if it is present in table 1
insert into table2 (data, timestamp)
select 'myData', '12:00 1999-01-01'
from table1
where exists (
select 1 from table1
where timestamp = '12:00 1999-01-01'
)
limit 1
Then run your the query for your 1st bullet i.e. insert into table1 only if the data doesn't already exist
insert into table1 (data, timestamp)
select 'myData', '12:00 1999-01-01'
from table1
where not exists (
select 1 from table1
where timestamp = '12:00 1999-01-01'
)
limit 1
Running both these queries will always only insert 1 row into 1 table because if the row exists in table1, the not exists condition of the 2nd query will be false and if it doesn't exist in table1, then the exists condition of the 1st query will be false.
You may want to consider creating a unique constraint on table1 to automatically prevent duplicates so you can use insert ignore for your inserts into table1
alter table table1 add constraint myIndex (timestamp);
insert ignore into table1 (data,timestamp) values ('myData','12:00 1999-01-01');
A regural INSERT statement can insert records into one table only. You have 2 options:
Code the logic within the application
Create a stored procedure within mysql and code the application logic there
No matter which route you choose, I would
Add a unique index on the timestamp column in both tables.
Attempt to insert the data into the 1st table. If the insert succeeds, everything is OK. If the timestamp exists, then you will get an error (or a warning depending on mysql confioguration). Your solution handles the error (in mysql see DECLARE ... HANDLER ...).
Insert the data into the 2nd table using INSERT INTO ... ON DUPLICATE KEY UPDATE ... statement, which will insert the data if the timestamp does not exists, or updates the record if it does.
Trying to merge two game servers' tables that have this structure:
map | authid | name | time | date | ...
I would like to replace a row only if the time value of table2 is less than that of table1 AND ONLY if the map and authid values are BOTH the same. If the time values in table2 are greater, then the row from the current table (table1) should be kept untouched. Otherwise (on different map or authid values), the row from table2 should simply be appended to table1.
My way would be to
1st: create a view for replacing rows and another with the correct result set that should be appended like
--view for update
create view ChangeTable1
as
select table2.map, table2.authid,table2.name, table2.date, table1.map as t1map, table1.authid as t1authid...from table1 to inner join table2 on table1.map=table2.map and table1.athid=table2.autid
where table1.time>table2.time
-- view for appending
create view Add2Table1
select table2.map, table2.authid,table2.name, table2.date... from table2 where concat(table2.map, table2.authid) not in (select concat(table1.map, table1.authid) from table1)
-- update statement based on first view ChangeTable1
update ChangeTable1 set t1date=date, t1somevalue=somevalue......
-- insert Statement based an second view Add2Table1
insert into table 1 (map, authid, name, time, date, .... as select map, authid, name, time, date,... from Add2Table1
I hope this helps. I mostly do MS SQL, so there might be some syntax issues that need translation to MYSQL, Nils
If you need a permanent process doing this, you might consider putting this in a stored procedure