I have a temporary table that I use to insert into the master db.
The temp table is named "temp_table"
The master table is "master"
I currently use the following command to update "master"
SELECT COUNT(*) FROM master;
SHOW COLUMNS FROM master;
INSERT INTO master
SELECT * FROM temp_table
ON DUPLICATE KEY UPDATE email = VALUES(email), phone = VALUES(phone)
Now, I want to be able to append field (counter) from the "temp table" into "master." The field already exists in both tables and I just want to be able to update or append it.
"counter" field in master may be empty or it may contain a number value already.
In cases where the value exists, it should append separated by a comma. Format (88,89,90)
In cases where the it's empty, it should update (88)
Thank you in advance.
I think you want:
on duplicate key update
email = values(email),
phone = values(phone),
counter = case when counter is null
then values(counter)
else concat(counter, ',', values(counter))
end
You can also phrase this with coalesce(), although the expression might be a bit more complicated to understand:
on duplicate key update
email = values(email),
phone = values(phone),
counter = concat(
coalesce(concat(counter, ','), ''),
values(counter)
)
Related
I am trying to solve the problem with insert new value into table. Primary key is ID not email... Before insert i need check other records for email value. If no one match inserted email, data is inserted. But i canot write correct code for that...
IF EXIST (SELECT email FROM users WHERE email = "email")
THEN
BEGIN
'We Have Records of this Customer'
END
ELSE
BEGIN
INSERT INTO users
VALUES (null,'email9','password9','forename9','lastname9')
END
END IF
Or:
IF SELECT COUNT(*) FROM users WHERE email = 'email' > 0
THEN
BEGIN
//email exist
END
ELSE
BEGIN
//inserting
END
END IF
This looks like a good use case for MySQL INSERT ... ON DUPLICATE KEY UPDATE syntax.
First of all, you want to create a UNIQUE constraint on column email. This is the proper way to represent your business rule:
ALTER TABLE users ADD CONSTRAINT users_unique_email UNIQUE (email);
Now, if the record that is about to be inserted would generate a duplicate on the primary key or on that UNIQUE constraint, then MySQL lets you turn the operation to an UPDATE instead.
In your case, since you want not to update anything in that case, you can simply re-assign the email column (which we know is the same here).
Consider:
INSERT INTO users
VALUES (null,'email9','password9','forename9','lastname9')
ON DUPLICATE KEY UPDATE SET email = 'mail9';
I cant comment, but I post this. I recommend making an external script like in python or java to do this for you by selecting * and parsing through the output because SQL itself does not have the power to do this.
I'm using MySQL 5.7 and for some reason my INSERT statement isn't working as before even though the syntax looks correct. It's error-ing out on the where statement...
SQL:
insert into users(age) values('16') where username='r';
If the row for username r already exists perhaps you are looking to update the age value instead?
Use: update users set age = 16 where username = 'r' instead.
Also, I'm just guessing here, but maybe age holds a numeric value, and if so you can remove the quotes around 16.
That syntax isn't correct. You can't use where like that. Perhaps you want something like:
insert into users (username, age)
values ('r', '16')
http://dev.mysql.com/doc/refman/5.7/en/insert.html
Alternatively if that user already exists, you might be looking for an update statement instead:
update users set age = '16' where username = 'r'
INSERT statements must not contain a WHERE clause. Remove it.
If, in fact what you are trying to do is update an existing row, use an UPDATE statement, not an INSERT statement.
update users set age = '16' where username='r';
If you want to insert new records in your table, you have to write query for inserting data.
SQL INSERT INTO Statement syntax is this:
INSERT INTO table_name (column1,column2,column3,...)
VALUES (value1,value2,value3,...);
In your case, if you don't have the record in your database, your query will look like this:
INSERT INTO users (username, age)
VALUES ('r', '16')
But if you want to update existing records in your table, you have to write query for updating data using the SQL UPDATE Statement.
The syntax for this is:
UPDATE table_name
SET column1=value1,column2=value2,...
WHERE some_column=some_value;
To update the record/s, you have to specify clause in WHERE which record should be modified.
To modify age of user/s with username that is equals 'r', this is the query:
UPDATE users SET age = 16 WHERE username = 'r'
but if you want to modify for all users which usernames starts with 'r':
UPDATE users SET age = 16 WHERE username = 'r%'
I hope this explanation will help you to understand better SQL statements for INSERT new and UPDATE existing records.
I'm using a third party mysql table (ie I can't change any of its properties) and I have a row that has id (key), name and value.
I want to store unique cache keys into a row with the name cacheKeys.. and this is my sql statement
$query = "INSERT INTO ".$tableName." (name, value) VALUES ('CacheKeys', '".$key."') ON
DUPLICATE KEY UPDATE value = CONCAT_WS (',', $tableName.value, '$key')";
I've already implemented my caching algorithm, so that every time someone adds a cache key, I check to see if it already exists (from the CacheKeys row above), if it does I fetch it from cache.. otherwise I store it.
Problem is it seems that the sql write operation takes time, and it often stores duplicate cacheKeys
ie: currencies,defaultCurrencyId,user19,currency1,currency1,currency1,currency1,currency1
So I need to check to see that I'm not adding a duplicate key into the cacheKeys field.. and I need to do that using SQL (using php, ie regex etc would just be waaaay to expensive).
Try this::
INSERT INTO tb (firstname, lastname) VALUES ('Jack', 'Doe') IF NOT
EXISTS ( SELECT * FROM tb WHERE firstname='Jack' AND lastname='Doe' );
I know that you can use ON DUPLICATE KEY UPDATE to update a certain value if there is a record for that key already,
I can do this:
INSERT INTO `tableName` (`a`,`b`,`c`) VALUES (1, 2, 3)
ON DUPLICATE KEY UPDATE `a`=1, `b`=2, `c`=3
But how can I do this without having to write out the columns and values twice?
Unfortunately not.
You can get half-way there by not having to repeat the value:
INSERT INTO `tableName` (`a`,`b`,`c`) VALUES (1,2,3)
ON DUPLICATE KEY UPDATE `a`=VALUES(`a`), `b`=VALUES(`b`), `c`=VALUES(`c`);
But you still have to list the columns.
use REPLACE INTO
The meaning of REPLACE INTO is that IF the new record presents new key values, then it will be inserted as anew record.
IF the new record has key values that match a pre-existing record,then the key violation will be ignored and the new record will replace the pre-existing record.
If it is useful, I made a query to avoid writing by hand the last part of the "on duplicate" query, for versions >= 5.0:
SELECT GROUP_CONCAT( CONCAT(COLUMN_NAME,"=values(", COLUMN_NAME,")") SEPARATOR ", ") FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'database_name' AND TABLE_NAME = 'table_name';
and its output is this:
a=values(a), b=values(b), c=values(c), d=values(d)
on a table that has columns a,b,c and d, so you can append to the first part of the query:
INSERT INTO `tableName` (`a`,`b`,`c`, `d`) VALUES (1,2,3,4) ON DUPLICATE KEY UPDATE a=values(a), b=values(b), c=values(c), d=values(d)
UPDATE:
For a very long list of columns you may see a truncated output, you may use this statement before the query above (thanks Uncle iroh):
SET SESSION group_concat_max_len = 1000000;
per #BhendiGawaar's comment on #Lightness Races in Orbit's answer, here is the MySQL 8.019+ version:
INSERT INTO t1 (a,b,c) VALUES (1,2,3),(4,5,6) AS new
ON DUPLICATE KEY UPDATE c = new.a+new.b;
OR
INSERT INTO t1 (a,b,c) VALUES (1,2,3),(4,5,6) AS new(m,n,p)
ON DUPLICATE KEY UPDATE c = m+n;
Works with set as well:
INSERT INTO t1 SET a=1,b=2,c=3 AS new
ON DUPLICATE KEY UPDATE c = new.a+new.b;
INSERT INTO t1 SET a=1,b=2,c=3 AS new(m,n,p)
ON DUPLICATE KEY UPDATE c = m+n;
Copied directly from MySQL Docs
The deprecation warning about the use of VALUES:
The use of VALUES() to refer to the new row and columns is deprecated beginning with MySQL 8.0.20, and is subject to removal in a future version of MySQL. Instead, use row and column aliases, as described in the next few paragraphs of this section.
i know this is an old question, and this is a somewhat unconventional answer, but i ran into the same thing and was having issues with setting the group_concat_max_len property mentioned in another answer and was always getting a truncated result. Another option that I ultimately went with when writing a long script was to use this formula in excel:
=SUBSTITUTE(TRIM(A1), ",", "") & " = VALUES(" & SUBSTITUTE(TRIM(A1), ",", "") & "),"
where A1 is the cell you copy the field name into. To do this quickly, I'd right click the table and copy the select statement to the clipboard, which gives you all the colum names, the formula removes the commas.
Hope this helps someone!
I want to do all these update in one statement.
update table set ts=ts_1 where id=1
update table set ts=ts_2 where id=2
...
update table set ts=ts_n where id=n
Is it?
Use this:
UPDATE `table` SET `ts`=CONCAT('ts_', `id`);
Yes you can but that would require a table (if only virtual/temporary), where you's store the id + ts value pairs, and then run an UPDATE with the FROM syntax.
Assuming tmpList is a table with an id and a ts_value column, filled with the pairs of id value, ts value you wish to apply.
UPDATE table, tmpList
SET table.ts = tmpList.ts_value
WHERE table.id = tmpList.id
-- AND table.id IN (1, 2, 3, .. n)
-- above "AND" is only needed if somehow you wish to limit it, i.e
-- if tmpTbl has more idsthan you wish to update
A possibly table-less (but similar) approach would involve a CASE statement, as in:
UPDATE table
SET ts = CASE id
WHEN 1 THEN 'ts_1'
WHEN 2 THEN 'ts_2'
-- ..
WHEN n THEN 'ts_n'
END
WHERE id in (1, 2, ... n) -- here this is necessary I believe
Well, without knowing what data, I'm not sure whether the answer is yes or no.
It certainly is possible to update multiple rows at once:
update table table1 set field1='value' where field2='bar'
This will update every row in table2 whose field2 value is 'bar'.
update table1 set field1='value' where field2 in (1, 2, 3, 4)
This will update every row in the table whose field2 value is 1, 2, 3 or 4.
update table1 set field1='value' where field2 > 5
This will update every row in the table whose field2 value is greater than 5.
update table1 set field1=concat('value', id)
This will update every row in the table, setting the field1 value to 'value' plus the value of that row's id field.
You could do it with a case statement, but it wouldn't be pretty:
UPDATE table
SET ts = CASE id WHEN 1 THEN ts_1 WHEN 2 THEN ts_2 ... WHEN n THEN ts_n END
I think that you should expand the context of the problem. Why do you want/need all the updates to be done in one statement? What benefit does that give you? Perhaps there's another way to get that benefit.
Presumably you are interacting with sql via some code, so certainly you can simply make sure that the three updates all happen atomically by creating a function that performs all three of the updates.
e.g. pseudocode:
function update_all_three(val){
// all the updates in one function
}
The difference between a single function update and some kind of update that performs multiple updates at once is probably not a very useful distinction.
generate the statements:
select concat('update table set ts = ts_', id, ' where id = ', id, '; ')
from table
or generate the case conditions, then connect it to your update statement:
select concat('when ', id, ' then ts_', id) from table
You can use INSERT ... ON DUPLICATE KEY UPDATE. See this quesion: Multiple Updates in MySQL
ts_1, ts_2, ts_3, etc. are different fields on the same table? There's no way to do that with a single statement.