Php SQL查询到不同的表并显示所有

在我的PHPWeb上，我有3种内容类型，它们保存在不同的表上，具有不同的列数

例如：

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

我正在做一个搜索系统，在同一个选择中搜索每种类型，最后显示所有结果

例如：

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)

现在我有三个不同的函数来对每种类型进行查询，但我不喜欢这样，因为我无法对它进行分页

我需要一次查询三个表。

谢谢你

像这样使用

联合

（隐式独立）或

联合所有人

：

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.

使用

UNION

（隐式distinct）或

UNION ALL

如下：

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.

---

这将显示找到文本的表名

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%'

---

这将显示找到文本的表名

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%'

您也可以这样做：

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%'

您也可以这样做：

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%'