SQL中自然连接和内部连接的区别

先决条件 – 连接(内部、左、右和完全连接)
1. 自然连接：
自然连接基于相同的属性名称和数据类型连接两个表。结果表将包含两个表的所有属性，但只保留每个公共列的一个副本。

例子：
考虑下面给出的两个表：

学生桌

标记表

考虑给定的查询

SELECT * 
FROM Student S NATURAL JOIN Marks M;

输出：

2. 内连接：
内连接基于在 ON 子句中明确指定的列连接两个表。结果表将包含两个表中的所有属性，还包括公共列。

例子：
考虑以上两个表，查询如下：

SELECT * 
FROM student S INNER JOIN Marks M ON S.Roll_No = M.Roll_No; 

输出 ：

SQL 中 Natural JOIN 和 INNER JOIN 的区别：

SR.NO.	NATURAL JOIN	INNER JOIN
1.	Natural Join joins two tables based on same attribute name and datatypes.	Inner Join joins two table on the basis of the column which is explicitly specified in the ON clause.
2.	In Natural Join, The resulting table will contain all the attributes of both the tables but keep only one copy of each common column	In Inner Join, The resulting table will contain all the attribute of both the tables including duplicate columns also
3.	In Natural Join, If there is no condition specifies then it returns the rows based on the common column	In Inner Join, only those records will return which exists in both the tables
4.	SYNTAX: SELECT * FROM table1 NATURAL JOIN table2;	SYNTAX: SELECT * FROM table1 INNER JOIN table2 ON table1.Column_Name = table2.Column_Name;