如何联接列中具有相同值的两个表

Question

Every One It's Related To MYSQL Query... I have Two Tables ... Table A is like

|ID | Field 1| Field 2 |
------------------------
| 01 | ASD    | SDF     |
------------------------
| 02 | ghg    | OOi     |
------------------------

B is Like

------------------------
|ID | Field A | Field B |
-------------------------
| 1 | XYZ     | AB01    |
| 2 | XYZ     | AB02    |
-------------------------

Now in Field B In Table B Value - AB01 here 01 is the Value of ID Of Table A .

Now My Question is that How to use inner Join in Both A AND B Table

Like From B inner Join TableA On ??? [What will be in On Clause ...??]

Answer 1

Assuming ID is a string between 01 and 99 :

select  *
from    TableA a
join    TableB b
on      a.id = substring(b.FieldB, 3, 2)

Answer 2

Try this
DECLARE @RESULT TABLE
(        
        ID      INT, 
        Field_1 varchar(10),
        Field_2 varchar(10)

)        
INSERT @RESULT VALUES
(01, 'ASD','SDF')
,(02, 'ghg','OOi')

DECLARE @RESULT1 TABLE
(        
        ID      INT, 
        Field_a varchar(10),
        Field_b varchar(10)

)        
INSERT @RESULT1 VALUES
(01, 'xyz','ab01')
,(02, 'xyz','ab02')

select * from  @RESULT r1 inner join @RESULT1 r2
on right(r2.Field_b,2)=r1.id 

Answer 3

// 像这样

SELECT * FROM TableNAme INNER JOIN SecondTableName ON TableName.ID=SecondTableName.ID;

Answer 4

Well you can use SUBSTRING function like:

SELECT * FROM TableA a
INNER JOIN TableB b ON a.id = SUBSTRING(b.FieldB, 3, 2)

This will return you all records.

SUBSTRING in mysql have three params.

• your field name (your field name)
• starting point (where you want to start)
• length (how many character do you want)

Like:

SUBSTRING( string, start_position, [ length ] ) 

or

SUBSTRING( string FROM start_position [ FOR length ] )