Question

I have two tables:

Table A:

| id | type   | name
| 1  | Person | Fred
| 2  | Animal | Rover
| 3  | Animal | Snowball
| 4  | Person | Mary

Table B:

| id | city
| 1  | NYC
| 4  | Charlotte

What I want:

| id | type   | name     | city
| 1  | Person | Fred     | NYC
| 2  | Animal | Rover    | NULL
| 3  | Animal | Snowball | NULL
| 4  | Person | Mary     | Charlotte

In other words, Table A is a table of People and Animals. Table B is a table of the cities people live in. I would like to (In a single query, if possible) get every result from Table A and, if it’s a person, get that person’s city in Table B. Is that possible in a single query? If not, what is the fastest way?

I’ve tried to do a simple join (e.g. “SELECT * FROM tableA,tableB WHERE tableA.id==tableB.id”), but doing that only gets the results of the people and not the animals.

thx!

Answer 1

Use LEFT JOIN on this

SELECT  a.*, b.city
FROM    tableA a
        LEFT JOIN tableB  b
            ON a.ID = b.ID

SQLFiddle Demo

and assuming that only person has records on tableB