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...
Lastly, we have the FULL OUTER JOINS. This type of join combines both the RIGHT and LEFT outer joins. As a result, the join retrieves all rows when there is a match in either the left or the right table. If there is no match, the join returns the NULL values for the columns from...
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。
SELECTcriteria_id,country_code,country_name,fips_codeFROMGoogle_Ads_GeoTargets gtFULLOUTERJOINCountry_Code ccONgt.country_code=cc.fips_code; 查询结果: RIGHT JOIN 右连接与左连接相同,除了 RIGHT JOIN 子句返回表中的所有行,而 FROM 子句只返回表中匹配的行。 因为 RIGHT JOIN 的结果可以通过在 LEFT JOI...
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
inner 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 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 ...
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) ...
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 ...
Example: SQL LEFT Join -- left join the Customers and Orders tablesSELECTCustomers.customer_id, Customers.first_name, Orders.amountFROMCustomersLEFTJOINOrdersONCustomers.customer_id = Orders.customer; Run Code Here's how this code works:
LEFT OUTER JOIN的语法如下: SELECTcolumn1,column2,...FROMleft_tableLEFTOUTERJOINright_tableONleft_table.columnX=right_table.columnY; 其中,left_table是左表,right_table是右表。columnX和columnY是指定联接条件的列。 示例: 假设我们有两个表Customers和Orders: ...