-SQL Outer Join sometimes produces ambiguity, it is recommended to use the SQL-92 syntax.
Use left Outer Join
Assume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The followin
to use the SQL-92 syntax.
Use left Outer Join
Assume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Join of transact-
Time limit:2000/1000 MS (java/others) Memory limit:262144/262144 K (java/others)Total submission (s): 1100 Accepted Submission (s): 674Problem Descriptionhave You ever played the video game Minecraft? This game had been one of the world's most popular game in recent years. The world of Minecraft are made up of lots of
1x1x1 blocks in a 3D map. Blocks is the basic units of structure in
House BuildingTime limit:2000/1000 MS (java/others) Memory limit:262144/262144 K (java/others)Total submission (s): 1122 Accepted Submission (s): 689Problem Descriptionhave You ever played the video game Minecraft? This game had been one of the world's most popular game in recent years. The world of Minecraft are made up of lots of1x1x1 blocks in a 3D map. Blocks is the basic units of structure in
SQL-92 syntax. Use left Outer Join Assume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ). To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Join of transact-SQL: Use pubs
Unity game: North America market research independent developers return to the publisher model, unity North America
The data from an industry survey at this game developer conference gave me some new thoughts on the trend of Self-release of games. This survey sampled 2014 participants from the 2000 North American game developers conference. The results show that the proportion of self-released games by developers has decreased, while the proportion of self-released games by searching for
SQL-92 syntax be used.
Using a LEFT OUTER join
Suppose you join the authors table and the publishers table on the city column. The results are displayed only for authors residing in the publisher's city (in this case, Abraham Bennet and Cheryl Carson).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 left outer join. The following are queries and results for Transact-SQL left-outward
get the same result by typing less characters [Zi Fu:Select productid, productname from northwind. DBO. products where categoryid in (1, 4, 5)Project [Xiang Mu] After the in keyword [Guan Jian Zi] must be separated by commas and enclosed in brackets.In the titleauthor table, Query [Cha Zhao] For the au_id of all authors whose royalties are less than 50% in any of the following queries, and then select [Xuan ZE] au_id andNames of all authors matching the titleauthor query results:Select au_lname
the SQL-92 syntax.
Use left Outer JoinAssume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).
To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Join of transact-SQL:
Use
Internal ConnectionOnly display the join of matching rows in two join tables
Example:SelectTitles. Title, publishers. pub_name
FromTitles inner join
Publishers on titles. pub_id = publishers. pub_id
Left Outer JoinIncludes all rows in the first named table (left table, which appears on the far left of the join clause. Does not include unma
authors table and the publishers table are joined in the city column. The result is only displayed in
Author of the publisher's City (in this example, Abraham Bennet and Cheryl Carson)
).
To include all the authors in the results, regardless of whether the publisher lives in the same city, use SQL-
92 left outer join. The following are the query results of the left outer join of Transact-SQL:
USE pubs
SELECT a. au_fname, a. au_lname, p. pub_name
Outer JoinAssume that the authors table and the publishers table are joined in the city column. The results only show the author of the publisher's city (Abraham Bennet and Cheryl Carson in this example ).To include all authors in the results, regardless of whether the publisher lives in the same city, use the SQL-92 to connect left out. The following are the query results of the left Outer Join of Transact-SQL:USE pubsSELECT a. au_fname, a. au_lname
The data from an industry survey of the Game Developers Conference gave me some new ideas about the game's self-release trend. The survey , which took a sample of 2000 participants from the North American Game Developers Conference, showed that the percentage of developers who have released their games has fallen, while the proportion of vendors looking for publishers has risen. Comparing 2014 and 2013 data, it is found that developers who have releas
less than 50% in any of the following queries, and then select au_id andNames of all authors matching the titleauthor query results:Select au_lname, au_fname from authors where au_id in (select au_id from titleauthor where royaltyper The results show that some authors belong to the category of less than 50%.Not in: subqueries introduced by the not in keyword also return a column of zero or more values.The following query lists the names of publishers
row in the same two tables meets the join conditions. The inner join removes rows that do not match any row in the other table. Outer Join will return fromAll rows of at least one table or view mentioned in the clause, as long as these rows comply with any where or havingSearch criteria. Searches all rows in the left table referenced by the left Outer Join and all rows in the right table referenced by the right outer join. All rows of the two tables in the complete external join will be returne
code editing window is changed to the alter keyword, which is used to change any existing stored procedure. To run the stored procedure, click its node and select "Run stored procedure" from the context menu ".
4. Create a stored procedure with parameters:
We have created a simple stored procedure without parameters. Many stored procedures with parameters are often used in actual applications. Stored Procedures with parameters are generally used to update or insert data. We can use the same op
joins are sometimes ambiguous, so it is recommended to use the SQL-92 language
Method.
Using a LEFT OUTER join
Suppose you join the authors table and the publishers table on the city column. Results are displayed only in
Author of the city where the publisher resides (in this case Abraham Bennet and Cheryl Carson
)。
To include all authors in the results, regardless of whether the publisher lives in the same city, use the sql-
92 left outer join
Difference
Link:
As a verb, it means combining the contents of two or more tables and producing a result set that merges the columns and rows of each table. Table joins generally use the data that they have in common. For example, you can join a titles table and a publishers table with a common pub_id column to produce a result set that contains the title information and publisher information.
As a noun, the process or result of joining a ta
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.