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SELECT data FROM two tables in MySQL

What I have: The next structure:

table_zero
-> id (PRIMARY with auto increment)
-> other

table_1
-> id (foreign key to table zero id)
-> varchar(80) Example value: (aahellobbb)
-> one_field

table_2
-> id (foreign key to table zero id)
-> varchar(160) Example value: (aaececehellobbb)
-> other_field

What I want: Search and get an (id,varchar) array containing all matches with the LIKE '%str%' on the varchar field. For example, if I search with the "hello" string, then I should get both example values with their respective ids. These ids are always going to be different, since they are references to a PRIMARY KEY.

What I tried : I tried with UNION ALL but it does not work with LIMITS in my example.

By using UNION you may get several times rows with the same ID. What about using LEFT JOIN ?

If I've understood your question:

SELECT table_zero.id, table_1.varchar_field, table_2.varchar_field
FROM table_zero
  LEFT JOIN table_1 ON table_zero.id = table_1.id
  LEFT JOIN table_2 ON table_zero.id = table_2.id
WHERE table_1.varchar_field LIKE '%str%'
  OR table_2.varchar_field LIKE '%str%'

Try this

SELECT *
FROM 
(
SELECT table_zero.id AS ID, table_1.varchar_field AS field
FROM table_zero
  JOIN table_1 ON table_zero.id = table_1.id
WHERE table_1.varchar_field LIKE '%str%'
UNION
SELECT table_zero.id, table_2.varchar_field  AS field
FROM table_zero
  JOIN table_2 ON table_zero.id = table_2.id
) tbl
WHERE 
tbl.field LIKE '%str%'
SELECT table_zero.id, table_1.varchar_field, table_2.varchar_field
FROM table_zero
  LEFT JOIN table_1 ON table_zero.id = table_1.id
  LEFT JOIN table_2 ON table_zero.id = table_2.id
WHERE table_1.varchar_field LIKE '%str%'
  OR table_2.varchar_field LIKE '%str%'

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