SELECT CategoryName, ProductName FROM Categories INNER JOIN Products ON Categories.CategoryID = Products.CategoryID; 在前面的示例中,CategoryID 是被联接字段,但是它不包含在查询输出中,因为它不包含在 SELECT 语句中。若要包含被联接字段,请在 SELECT 语句中包含该字段名,在本例中是指 Categories.CategoryID。
select * from 部门, 组织 where 部门.组织编号 = 组织.编号 left outter join 格式: select * from 部门 left join 组织 on 部门.组织编号 = 组织.编号 格式: select * from 组织 left join 部门 on 组织.编号 = 部门.组织编号 目的:将左表的所有记录列出,右表中只要符合on条件的,与左表记录相拼合,...
SQL Statement V (SELECT – LEFT JOIN / RIGHT JOIN / FULL JOIN) TABLE 1 – Test_A ID Text 1 A 2 B 4 D 5 E TABLE 2 – Test_B ID Text 1 A 3 C 5 E SQL 指令 及 Result FULL JOIN SELECT TableA.ID, TableB.ID, TableA.Text, TableB.Text FROM Test_A TableA...
LEFT JOIN 关键字会从左表 (table_name1) 那里返回所有的行,即使在右表 (table_name2) 中没有匹配的行。即使右表中没有匹配,也会返回匹配结果为NULL。 SELECT column_name(s) FROM table_name1 LEFT JOIN table_name2 ON tablename1.column_name=table_name2.column_name; 绿色部分,为两表的左关联结果...
SQL LEFT JOIN The SQLLEFT JOINcombines two tables based on a common column. It then selects records having matching values in these columns and the remaining rows from the left table. Example -- left join Customers and Orders tables based on their shared customer_id columns-- Customers is ...
可以使用LEFT JOIN将cz表与stu表进行两次关联，一次是通过czid字段，另一次是通过bczid字段。示例SQL语句如下：sqlSELECT a.name AS 操作人, b.name AS 被操作人FROM czLEFT JOIN stu a ON a.id = cz.czidLEFT JOIN stu b ON b.id = cz.bczid 在这个查询中，a和b是stu表的两个...
SQL语句：sqlSELECT a.id, a.user_name, b.over FROM user1 a LEFT OUTER JOIN user2 b ON a.user_name = b.user_name;2. RIGHT OUTER JOIN 概念：返回右表中的所有记录以及左表中满足连接条件的记录。如果左表中没有满足条件的记录，则结果中左表的部分将包含NULL。 SQL语句：sqlSELECT ...
'; SELECT * FROM (SELECT id FROM table_to_be_queried SNAPSHOT BETWEEN start_snapshot_id AND end_snapshot_id) C; (SELECT * FROM table_to_be_queried SNAPSHOT SINCE start_snapshot_id) a INNER JOIN (SELECT * from table_to_be_joined SNAPSHOT AS OF your_chosen_snapshot_id) b ON a...
SELECT-- C.4p.nameAS[Package], c.object_nameAS[Event], c.nameAS[Column-for-Predicate-Data], c.descriptionAS[Column-Description]FROMsys.dm_xe_object_columnsAScJOINsys.dm_xe_objectsASoONo.name = c.object_nameJOINsys.dm_xe_packagesASpONp.guid = o.package_gu...
select 语法的处理顺序 The following steps show the processing order for a SELECT statement. FROM ON JOIN WHERE GROUP BY WITH CUBE or WITH ROLLUP HAVING SELECT DISTINCT ORDER BY TOP 这些步骤执行时, 每个步骤都会产生一个虚拟表,该虚拟表被用作下一个步骤的输入。这些虚拟表对调用者(客户端应用程序或...