Select * from table1 and table2 where table1. The id=table2. Id

From the back of the form is why write this

CodePudding user response:

Behind the multi-table query, WHERE is the relationship between the two tables, such as class table and student table

CodePudding user response:

Actually here is equivalent to two table join:

 select * from table1 inner join table2 on table1. The id=table2. Id 

However, from behind the practice of writing multiple table names, it is not recommended at Microsoft,

Therefore, have to do is to know about this, you still don't use this kind of writing is good,

CodePudding user response:

refer to the second floor of gypsy song response:

here is equivalent to two table join:

 select * from table1 inner join table2 on table1. The id=table2. Id 

However, from behind the practice of writing multiple table names, it is not recommended at Microsoft,

Therefore, have to do is to know about this, you still don't use this kind of writing is good,

thank you very much

CodePudding user response:

reference JHT_2020 reply: 3/f

Quote: refer to the second floor of gypsy song response:

Actually here is equivalent to two table join:

 select * from table1 inner join table2 on table1. The id=table2. Id 

However, from behind the practice of writing multiple table names, it is not recommended at Microsoft,

Therefore, have to do is to know about this, you still don't use this kind of writing is good,

thank you very much

You're welcome, nothing to post bar,

CodePudding user response:

Microsoft does not recommend the from the back to write more than one table, is due to the so write affect performance or other reasons?

CodePudding user response:

reference 5 floor victory610 reply:

Microsoft does not recommend the from the back to write more than one table, is due to the so write affect performance or other reasons?

Main or readability, normative considerations,