mysql sql statement - SQL INSERT INTO SELECT

I have a unique id on the both table : customerid

use Update if the customer Id already exists in table2

use Insert into if the customer id not exists in table2

something like this should do if and only if your customer_id field is unique in the destination table2

insert into table2 select customer_id, customer_name from table1 on duplicate key update customer_name = VALUES (customer_name)

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if you don't have the index, try something like this

lock database

create table temp as select table2.*,table1.customer_name from table2 inner join table1 on table1.customer_id =  table2.customer_id

rename table2 to t , temp to table2

drop table t

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for update:

Update table2 a
inner join table1 b
on a. customerid = b.customerid
set a.customername = b.customername

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for insert:

Insert into table2 (customerid, customername)
select a.customerid, a.customername
from table1 a left join table2 b
on a.customerid = b.customerid
where b.customerid is null

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code not tested, pls customize accordingly.

Dear Ryan Chong,
what does a mean? I mean what is table2 a?
a = column?

nope, a is the alias of the table.

we can write:

 table2 a

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as

 table2 as a

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did you try using the "on duplicate key update" way ? unless there is something not workable, it is the only way to do it in a single query

Dear skullnobrains, Ryan Chong

I'm sorry, I couldn't manage it..

My actual table name is "bayibilgileriiki" which has the data of the customer names.
and the a column name is "adi"

I want to copy "adi" coloumn to "KullaniciBilgileriiki" table's "isim" column.
"isim" column is now NULL.

I have unique customer id on both tables which coloumn name is "uid" for both of them

could you help me please?

thank you

just for reference since you already got a working solution

insert into KullaniciBilgileriiki ( uid , isim ) select uid,adi from bayibilgileriiki on duplicate key update isim = VALUES (isim)