mysql 中create table with as
时间: 2024-02-21 14:01:42 浏览: 33
"CREATE TABLE ... AS" 语句是 MySQL 中用于创建一个新表并从一个或多个现有表中选择数据的语句。它的基本语法如下:
```
CREATE TABLE new_table
AS
SELECT column1, column2, ...
FROM existing_table
WHERE ...
```
这个语句将创建一个名为 "new_table" 的新表,该表包含从 "existing_table" 中选择的特定列和行。可以使用 "WHERE" 子句来指定选择哪些行。注意,新表中的列名和数据类型将与 "SELECT" 子句中的列名和数据类型相匹配。如果不指定列名,则将使用 "SELECT" 子句中的列名。
相关问题
mysql with as
MySQL does not support the "WITH" keyword for common table expressions (CTEs) like some other database systems such as PostgreSQL or SQL Server. However, you can achieve similar functionality by using subqueries or temporary tables.
For example, suppose you have a query using a CTE in PostgreSQL:
```
WITH cte AS (
SELECT column1, column2
FROM table1
WHERE condition
)
SELECT *
FROM cte
```
In MySQL, you can rewrite this query using a subquery:
```
SELECT *
FROM (
SELECT column1, column2
FROM table1
WHERE condition
) AS subquery
```
Alternatively, you can use a temporary table to store the intermediate results:
```
CREATE TEMPORARY TABLE temp_table AS (
SELECT column1, column2
FROM table1
WHERE condition
);
SELECT *
FROM temp_table;
```
Keep in mind that the specific approach to use depends on the complexity of your query and your specific requirements.
mysql5 with as
"WITH AS" 是一个用于查询中的关键字,它通常用于定义一个可重用的子查询(也称为公共表表达式)。在 MySQL 5 中,不支持 "WITH AS" 关键字,但可以通过创建视图来实现相似的功能。视图是一个虚拟表,它由查询定义并存储在数据库中。您可以像使用普通表一样使用视图,并且可以在多个查询中重用它们。要创建视图,请使用 CREATE VIEW 语句。例如:
```
CREATE VIEW my_view AS
SELECT column1, column2, ...
FROM my_table
WHERE condition;
```
然后,您可以在查询中引用视图:
```
SELECT *
FROM my_view
WHERE column1 = 'value';
```
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