SQL查询到不同的表并显示全部

Question

On my php web I have 3 content type saved on different tables with different number of columns

for example:

Type 1 (X columns) (example: table_products)
Type 2 (Y columns) (example: table_customers)
Type 3 (Z columns) (example: table_posts)

I'm making a Search system that searchs on each type in the same Select, showing finally all results.

Example:

I search: foo

System searchs on: Type 1, type 2 and type 3 "foo" and shows:

- Product foo1
- Product foo2
- Customer foo1
- Customer foo2
- Customer foo3
- Post foo1
 (It's only an example)

Now I have three different functions to make the query on each type, but I don't like this because I can't paginate it.

I need to make a query that searchs on three tables at time.

Thank you

Answer 1

This will show the tableName on where the text has been found.

SELECT 'Product' tableName, type1
FROM table_product
WHERE type1 LIKE '%foo%'
UNION
SELECT 'Customer' tableName, type2
FROM table_Customer
WHERE type2 LIKE '%foo%'
UNION
SELECT 'posts' tableName, type3
FROM table_posts
WHERE type3 LIKE '%foo%'

Answer 2

Use UNION (implicit distinct) or UNION ALL like so:

SELECT Name FROM table_products  WHERE Name LIKE '%Foo%'
UNION ALL
SELECT Name FROM table_customers WHERE Name LIKE '%Foo%'
UNION ALL
SELECT Name FROM table_posts     WHERE Name LIKE '%Foo%'
-- This is only an example too.

Answer 3

You can also do so:

SELECT *
FROM(
  SELECT 1 AS Type, MyColumn FROM table_product
  UNION ALL
  SELECT 2 AS Type, MyColumn FROM table_customers
  UNION ALL
  SELECT 3 AS Type, MyColumn FROM table_posts
) AllResults
WHERE AllResults.MyColumn LIKE '%foo%'