sql inner join example

join column. If a row in the left table does not match a row in the right table, all selection list columns in the right table in the row of the associated result set are null.Right join or right outer join.The right outer connection is the reverse connection of the left outer connection. All rows in the right table are returned. If a row in the right table does not match a row in the left table, a null va

element in a to match the result of all elements in B, that is, the n*m combination. SELECT * from A cross JOIN B AA BB -------- -------- Item 1 Item 3 ^ Item 1 Item 4 +--- the first element in a, matching all elements in B Item 1 Item 5 | Item 1 Item 6 v Item 2 Item 3 ^ Item 2 Item 4 +--- a second element that matches all elements in B Item 2 Item 5 | Item 2 Item 6 v

table 2 on table 1. Field number = Table 2. Field number) INNER join table 3 on table 1. Field number = Table 3. Field number) INNER join table 4 on Member. Field number = Table 4. Field number) in NER JOIN table 5 on Member. Field number = Table 5. Field number Connect si

= Inner join> Left join = left Outer Join> Right join = right Outer Join> Full join = Full outer join> The number of records connected by a

all expressed, while the right table (B) only displays records that meet the search criteria (in this example:. aid = B. bid ).All records in Table B are null.--------------------------------------------2. Right joinThe SQL statement is as follows: select * from A right join B on A.aID = B.bID The result is as follows:Aid anum bid bname1 a20050111 1 20060324012

Categories.CategoryID.You can also link multiple on clauses in a JOIN statement, using the following syntax:SELECT fieldsFrom table1 INNER JOIN table2On table1.field1 compopr table2.field1 andOn table1.field2 compopr table2.field2 OROn table1.field3 compopr table2.field3;You can also nest JOIN statements with the foll

Categories.CategoryID.You can also link multiple on clauses in a JOIN statement, using the following syntax:SELECT fieldsFrom table1 INNER JOIN table2On table1.field1 compopr table2.field1 andOn table1.field2 compopr table2.field2 OROn table1.field3 compopr table2.field3;You can also nest JOIN statements with the foll

a20050113 3 20060324034 a20050114 4 20060324045 a20050115 NULL NULL(The number of rows affected is 5 rows)Result Description :The left join is based on the records of Table A, a can be regarded as the right table, and B can be regarded as left table.In other words, the records of the left table (A) will all be represented, and the right table (B) will only display records that match the search criteria (in the ex