access sql join syntax

JOINIf you want to get all the element items, you can use FULL JOIN :SELECT * fromA Full JOINB onAa=BB AA bb-------- --------Item1 -----+Item2 |Item3Item3 |Item4Item4 |Item5 +---Empty holes is NULL ' sItem6 |^ || |+---------------------+Again, note that the value of the missing data item is NULL . INNER JOININNER JOINJOINas is the case, the INNER general keyword can be omitted. INNER JOINonly the matching element items will be returned, that is, the

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

statement, which in this case refers to 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

Label: Inner JOIN (equivalent connection) returns only rows that have the same join field in two tables Left join returns records containing all the records in the left table and the equivalent of the junction fields in the right table Right join returns records that contain all the records in the right table and the s

Anum BID bname1 a20050111 1 20060324012 a20050112 2 20060324023 a20050113 3 20060324034 a20050114 4 2006032404Result Description :Obviously, only a.aid = B.bid records are shown here. This shows that inner join is not based on who, it only shows records that match the criteria. And the inner join can be used in conjunction with the where statement, such as: SELECT * from A innerjoin B on a.aid = b.bid wher

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 example: A.aid = b.bid).The low-record o

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 following syntax:SELECT fieldsFrom table1 INNER

statement, which in this case refers to 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

represented, and the right table (B) will only display records that match the search criteria (in the example: A.aid = b.bid). b table records are not sufficient for the place are null. 2.right join sql statements are as follows: Select from A Join B on A. AID = B.bid The results are as follows:AID Anum BID bname1 a20050111 1 20060324012 a20050112 2 200

in the SELECT statement, which in this case refers to 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

SQL inline syntax basic syntax (innerjoin) SELECT * FROM Table 1innerjoin table 2on table 1. userid table 2. useridsql inline syntax description: The preceding statement is used to query two tables, table 1 and table 2. If the userid fields in the two tables are the same, a row is displayed. 45it.com Note: The precedin

left join is exactly the opposite, this time it is based on the right table (B), where a table is not enough to fill with null. 4. Inner Join Example: 4.1Select * from A inner join B on a.aid = B.bid; This shows only the records of A.aid = B.bid. This shows that inner join is not based on who, it only shows records t

Label:There are currently two tables, Sgroup and Sgroupuser, which are associated by Gkey, while the Sgroup table records the group, and the Sgroupuser record is the user in the group, so there is no data in the Sgroupuser. You need to use the left join to get the data: The LINQ syntax is as follows: var sg = ( from the dc.sgroup in dc.sgroupuser on G.gkey equals Gu.gkey into L

SQL LEFT join instance and syntax usage Left joins and similar rights join operations can be used in any FROM clause to combine records from two tables. The left JOIN operation is used to create a left outer join, including all r

Label:Refer to the following two blog posts:The first is the SQL syntax: INNER join on, left join on, right join on detailed usage methodThe meaning and usage of the inner join, the left JOIN