TheRIGHT OUTER JOINworks exactly the opposite of theLEFT OUTER JOIN. In this operation, all the rows from the right table are returned, along with the rows from the left table that match the ones in the right table. Missing values in the left table are given a value ofNULL. Example: C...
因为 RIGHT JOIN 的结果可以通过在 LEFT JOIN 中交换两个连接的表名来实现,所以很少使用 RIGHT JOIN。 一个RIGHT JOIN 查询看起来像这样: 代码语言:javascript 复制 SELECTcriteria_id,country_code,country_name,fips_codeFROMGoogle_Ads_GeoTargets gtRIGHTJOINCountry_Code ccONgt.country_code=cc.fips_code SELF...
SQL将外部联合分为了右外部联合(right outer join)、左外部联合(left outer join)、完全外部联合(full outer join)3个类型。 左外部联合:LEFT OUTER JOIN 基本语法:SELECT column_list FROM table1 LEFT OUTER JOIN table2 ON condition 思想:OUTER JOIN语句表1中的所有记录都被返回在结果中,即使表2没有匹配的。
select A.*,B.* from A left outer join B on(A.a1=B.a2) 结果是: a1 b1 c1 a2 b2 01 数学 95 01 张三 02 语文 90 02 李四 03 英语 80 NULL NULL select A.*,B.* from A right outer join B on(A.a1=B.a2) 结果是: a1 b1 c1 a2 b2 01 数学 95 01 张三 02 语文 90 02 李四 ...
SQL OUTER JOIN – left outer join example The following query selects all customers and their orders: SELECTc.customerid, c.companyName, orderidFROMcustomers cLEFTJOINorders oONo.customerid = c.customeridORDERBYorderidCode language:SQL (Structured Query Language)(sql) ...
Example 1: LEFT OUTER JOIN Let us start with an OUTER JOIN. Suppose we want to retrieve all the customer information along with their payment information, if available. This makes a LEFT OUTER JOIN applicable as we want all customer information (on left) and payment information if available ...
SQL里 inner JOIN、 left (OUTER) JOIN 、right (OUTER) JOIN、 full (OUTER) JOIN 之间的区别 /* 直接上例子废话不多说 此例子里两张表之间相等的都是各自的主键 然而大部分情况下是A表的主键和B表里的外键相等, 所以就会存在B表里多行
INSERT INTO books （bk_id bk_title）VALUES （ LEFT JOIN EXAMPLE ）其余的列将被填充为默认值NULL 现在 可以使用之前曾用过的关于图书放置位置的查询 只需要将JOIN类型从INNER JOIN修改为LEFT OUTER JOIN:SELECT bk_title loc_shelf loc_position_left FROM books LEFT OUTER JOIN location ON ...
1.INNER JOIN SELECT * FROM TableA INNER JOIN TableB ON TableA.name = TableB.name 2.FULL [OUTER] JOIN (1) SELECT * FROM TableA FULL OUTER JOIN TableB ON TableA.name = TableB.name 4.RIGHT [OUTER] JOIN RIGHT OUTERJOIN 是后面的表为基础,与LEFT OUTER JOIN用法类似。这里不介绍了。
LEFT OUTER JOIN(左外连接)是一种关系型数据库查询操作,它用于联接两个表,并返回左表中的所有记录,以及右表中满足联接条件的记录。如果右表中没有与左表满足联接条件的记录,则返回的结果集中将包含 NULL 值。 在LEFT OUTER JOIN中,左表是查询的主表,而右表是被联接的表。查询会根据指定的联接条件,将左表和...