sql inner join example

For example: Table A have 12 (8 + 4) entries, 8 entries have valid relation with BTable B have 80 (77 + 3) entries, 77 entries have valid relation with. Then the return amount of join is:Cross join: 12*80Inner join: 77Full outer join: 77 + 4 + 3Left Outer

value.SELECT * from TableA full OUTER JOIN TableB on tablea.name = Tableb.nameYou can find the value without matching by the IS null:SELECT * from TableA full OUTER JOIN TableB on tablea.name = Tableb.nameWHERE tablea.id is null OR tableb.id is null 5. Cross joins a n*m combination of the data from table A and table B, the Cartesian product. If this regular session produces 4*4=16 records, we must filter t

product is not so complicated that the inner connection is more efficient than the cross-connection of the Cartesian product.SELECT * FROM table1 as a INNER joins Table2 as B on A.column=b.column3> outer JOIN outer JOIN1) left outer connection [OUTER] JoinSELECT * FROM table1 as a left [OUTER] JOIN on A.column=b.colum

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 numberConnect six data tables using: Slightl

(table 1 INNER join 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

if there are no corresponding values. SELECT * from dbo. Student a left JOIN dbo. Score B on A.sno=b.sno 　　 INNER JOIN Display Intersection SELECT * from dbo. Student a INNER JOIN dbo. Score B on A.sno=b.sno 　　 Right join all d

1. A. Union select Column1, column2 from table1 Union select Column1, column2 from Table2 B. Intersection join SELECT * FROM table 1 as a JOIN table2 B on A.name=b.name c. No in SELECT * "from table1 WHERE name does not" (SELECT name from table2) d. Cartesian product The SELECT * FROM table1 CROSS JOIN table2 is the same as the select * from Table1,table2 2. The

Tags: connecting left connection Ali data sheet full join left and right out combination case connections in SQL can be divided into inner joins, outer joins, and cross connections. 1. Cross join Without a WHERE clause, it will return the Cartesian product of the two tables connected, and the number of rows returning

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.ID = b.id). The low-record of table B is null.Step three: Perform right join effect [SQL] SELECT * FROM Table1 a right join