You can do the following (I guessed on table fields,etc) SELECT s.studentname , s.studentid , s.studentdesc , h.hallname FROM students s INNER JOIN hallprefs hp on s.studentid = hp.studentid INNER JOIN halls h on hp.hallid = h.hallid Based on your request for multiple halls you could do it this way. You just join on your … Read more
SELECT * FROM table1 LEFT JOIN table2 on table1.id = table2.id
You need to specify what table you are deleting from. Here is a version with an alias: DELETE w FROM WorkRecord2 w INNER JOIN Employee e ON EmployeeRun=EmployeeNo WHERE Company = ‘1’ AND Date=”2013-05-06″
They are functionally equivalent, but INNER JOIN can be a bit clearer to read, especially if the query has other join types (i.e. LEFT or RIGHT or CROSS) included in it.
That syntax isn’t valid in Oracle. You can do this: UPDATE table1 SET table1.value = (SELECT table2.CODE FROM table2 WHERE table1.value = table2.DESC) WHERE table1.UPDATETYPE=’blah’ AND EXISTS (SELECT table2.CODE FROM table2 WHERE table1.value = table2.DESC); Or you might be able to do this: UPDATE (SELECT table1.value as OLD, table2.CODE as NEW FROM table1 INNER JOIN … Read more
INNER JOIN is ANSI syntax that you should use. It is generally considered more readable, especially when you join lots of tables. It can also be easily replaced with an OUTER JOIN whenever a need arises. The WHERE syntax is more relational model oriented. A result of two tables JOINed is a cartesian product of … Read more
Reading this original article on The Code Project will help you a lot: Visual Representation of SQL Joins. Also check this post: SQL SERVER – Better Performance – LEFT JOIN or NOT IN?. Find original one at: Difference between JOIN and OUTER JOIN in MySQL.
Assuming you’re joining on columns with no duplicates, which is a very common case: An inner join of A and B gives the result of A intersect B, i.e. the inner part of a Venn diagram intersection. An outer join of A and B gives the results of A union B, i.e. the outer parts … Read more
from field_data_field_date_and_time fdt JOIN node on fdt.<field> = node.uid Without seeing your schema, it is hard to tell what the FK is here.