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
)
Related
I want to update a MySQL table from matlab in bulk. The current logic that I use iterates over the array and inserts it one-by-one which takes way too long.
Here is my current implementation-
function update_table(customer_id_list, cluster_id_list, write_conn)
num_customers = size(customer_id_list, 1);
for idx=1:num_customers+1
customer_id = customer_id_list(idx);
cluster_id = cluster_id_list(idx);
sql = strcat(sql, 'UPDATE table SET cluster_id = ', num2str(cluster_id), ' WHERE customer_id = ', num2str(customer_id));
exec(write_conn, sql);
end
end
Tried to look for documentation to do bulk update/insert, but haven't found anything yet.
Do an "upjoin" using a temporary table.
Build your update specification as a Matlab table array with all the cluster_id and customer_id pairs that specify the new values.
Create a SQL temporary table that contains columns for the key columns you'll be matching on and the columns to update.
CREATE TEMPORARY TABLE my_temp_table SELECT customer_id, cluster_id FROM table WHERE 1 = 0
Batch-insert your update specification data from Matlab into the temporary table using Matlab Database Toolbox's datainsert or sqlwrite.
Update the target table en masse by joining it to the temp table: UPDATE table SET targ.cluster_id = upd.cluster_id FROM table targ INNER JOIN my_temp_table upd ON targ.customer_id = upd.customer_id.
Drop the temp table.
Boom. If you're going to do this a lot, wrap it up in a generic upjoin() function.
See the Matlab documentation for datainsert and sqlwrite. Do not use fastinsert; despite its name, it is much slower than datainsert and sqlwrite.
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;
I want to write a Mysql query for the following scenario.
1.check if a table( ex: tableA) exists.
2.Check if data is there in the table.
3.If tableA exists and data is there in the table move all data to another table( ex: tableB) (tableB there in db and both tables are having same structure)
4.drop tableA
Is it possible to write a mysql query avoiding mysql stored procedure ?
I was able to do first three with the below query, but drop table was not possible.
Hope it helps!
There are two tables: table_1(old),table_2(new). Both have one column "ID".
insert into table_2(id) #inserts into table
select case when
(
select count(*) from table_1 a #checks if there are any records in the table
where exists #checks if table exists
(select 1 from table_1 b where a.id=b.id))>0 then
id
else 0 end
from table_1
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.
I have a mySQL db with duplicate records, as from the attached image.
I am asking for a query to delete all duplicate records based on date + time, for all tables (foreachtables) in db
Thanks
As far I could see, you dont have autoincrement primary key or foreign key.
If you dont have tables with foreign key or relation between, first you can list all your tables. After that, you can create a temporal "mirror" of one table (for eg, autogrill).
Then you can do a:
INSERT INTO TemporalTable
SELECT DISTINCT
or a
INSERT INTO TemporalTable
SELECT Id, Date, Time FROM autogrill GROUP BY Id, Date, Time HAVING COUNT(*) > 1
.
TRUNCATE or DELETE FROM
without where and then put again your data with
INSERT INTO autogrill
SELECT * FROM TemporalTable
BE AWARE if you have primary keys doing this.
How about you create and STORED PROCEDURE for this?
DELIMITER $$
CREATE PROCEDURE `DeleteDup`()
BEGIN
-- Drops the table.
DROP TABLE bad_temp;
-- Creates a temporary table for distincts record.
CREATE TABLE bad_temp(id INT, name VARCHAR(20));
-- Selects distinct record and inserts it on the temp table
INSERT INTO bad_temp(id,name) SELECT DISTINCT id,name FROM bad_table;
-- Delete All Entries from the table which contains duplicate
-- (you can add also condition on this)
DELETE FROM bad_table;
-- Selects all records from temp table and
-- inserts back in the orginal table
INSERT INTO bad_table(id,name) SELECT id,name FROM bad_temp;
-- Drops temporary table.
DROP TABLE bad_temp;
END$$
DELIMITER ;
Please change tablename and column name to your desired schema.
so when you finish creating your STORED PROCEDURE, you can use it like this:
CALL DeleteDup();
You can export your table using this request :
SELECT * FROM autogrill GROUP BY id
Then, empty your table, and import the export you made before. I don't know another easy way to erase duplicate entries using only a single request.
One easy way to do this is to copy all the distinct records into a new table or an export. Then delete all records in the original table and copy them back in.
Export NULL if table have autoincrement an for source use alias name, example :
INSERT INTO product
SELECT NULL,p.product_sku,
p.product_s_desc,
p.product_desc,
p.product_thumb_image,
p.product_full_image,
p.product_tech_data,
p.product_publish,
p.product_weight,
p.product_weight_uom,
p.product_length,
p.product_width,
p.product_height,
p.product_lwh_uom,
p.product_url,
p.product_in_stock,
p.product_available_date,
p.product_special,
p.create_date,
p.modify_date,
p.product_name,
p.attribute
FROM product AS p WHERE p.product_id=xxx;