MySQL从另一个表插入多个ID

Question

I have 2 table, first I retrieve all Ids like this:

select DISTINCT entity_id From table1

I want to create a bulk insert using entity_id and prevent duplicate if the entity_id have a specifique value in the colomn2:

example

    *********************************************
    *  ID   *  ENTITY_ID *  COLOMN2 *  value    *
    *********************************************
    *  1    *     230    *    20    *    1      *
    *  2    *     230    *   100    *    1      *
    *  3    *     280    *    20    *    0      *
    *  4    *     220    *    20    *    1      *
    *********************************************
    select DISTINCT entity_id From table1 // return : 230,280,220


    INSERT into table1 ('ENTITY_ID','COLOMN2','VALUE') VALUES([the select id],100,1) 
    WHERE COLOMN2<>100

or something like that?

the result need to be:

creating 2 insert... entity_id=220 and entity_id=280

with the colomn2=100 and value = 1

any idea ?

Answer 1

Use a subquery

INSERT INTO table1 ('ENTITY_ID','COLOMN2','VALUE')
(select DISTINCT entity_id ,100,1 FROM table2 WHERE column2<>100) 

Answer 2

If I'm understanding you correctly, you consider "duplicate" to mean BOTH "ENTITY_ID" and "COLOMN2" have the same value, ie:

(50, 50) & (50, 99) == not duplicate

(80, 42) & (99, 42) == not duplicate

(55, 66) & (55, 66) == duplicate

Can you create a compound unique key on your database? Such as, for mysql:

CREATE UNIQUE INDEX nodupes ON table1 (ENTITY_ID, COLOMN2);

You would then need to determine how to handle errors during the insert process.