Databases for Developers - Oracle数据库开发者基础培训

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这两个培训是为开发者准备的基础培训，分为基础和进阶两个培训。视频做的生动有趣，每个不到10分钟，但需要访问Youtube。不过练习和测验直接可以访问，练习中也包括在视频中的概念。

Databases for Developers: Foundations

在Module 9中，有个比较row by row commit和group commit性能的例子，蛮经典的。另外其中还有一个connect by level语句，可以生成序列：

declarestart_time   pls_integer;insert_count pls_integer := 50000;
beginstart_time := dbms_utility.get_time ();for i in 1 .. insert_count loopinsert into bricks values ( i, 'red', 'cube' );end loop;dbms_output.put_line ( 'Single-row duration = ' || ( dbms_utility.get_time () - start_time) );rollback;start_time := dbms_utility.get_time ();insert into bricksselect level, 'red', 'cube' from dualconnect by level <= insert_count;dbms_output.put_line ( 'Multi-row duration = ' || ( dbms_utility.get_time () - start_time) );rollback;
end;
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https://blog.jooq.org/2016/12/09/a-beginners-guide-to-the-true-order-of-sql-operations/?utm_content=buffer0c197&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Databases for Developers: Next Level

gotcha：陷阱
draw：平局

select * from (select colour, count(*) cfrom   bricksgroup  by colour
) brick_counts
join   colours
on     brick_counts.colour = colours.colour_name
and    brick_counts.c < colours.minimum_bricks_needed