Update rows in table 'A' with value 'Y', for matching records from a different table 'B"

Question

TESTDTA is the test database.
F41= First table
F42=Second table

Data from F41 TABLE

FLAG    STORE   NAME    NUMBER
S         1      A       A1
S         2      B       B2
S         3      C       C3

Data from F42 TABLE

STORE   NAME    NUMBER
1        A        A1
2        B        B2
3        C        C3
4        D        D4

I need to update values for the column "FLAG" in the tabel "F41" to value "P" if there is a matching record in the table "F42" .

I tried below SQL. But it has syntax error.

UPDATE TESTDATA.F41,TESTDATA.F42 SET F41.FLAG='P' 
WHERE F41.NAME=F42.NAME AND F41.NUMBER=F42.NUMBER

Can anyone help me to write this SQL?

Thanks in advance for your help

Answer 1

Perhaps a little cleaner

UPDATE F41 SET FLAG='P' 
 FROM  F41 A
 JOIN  F42 B on A.NAME=B.NAME AND A.NUMBER=B.NUMBER

Answer 2

if your DBMS is Oracle and If by "matching records" you mean all column values in F41 match F42 then this might answer your problem:

DDL:

create tabLe F41
(
    FLAG        varchar2(10)
   ,STORE_x       number
   ,NAME_x        varchar2(10)
   ,NUMBER_x      varchar2(10)
);

create tabLe F42
(
    STORE_x       number
   ,NAME_x        varchar2(10)
   ,NUMBER_x      varchar2(10)
);

Note: Added _x to the Columns STORE, NAME, NUMBER because those are reserved words in some DBMS.

DML:

insert into F41 (FLAG, STORE_x, NAME_x, NUMBER_x) values ('S', 1, 'A', 'A1');
insert into F41 (FLAG, STORE_x, NAME_x, NUMBER_x) values ('S', 2, 'B', 'B2');
insert into F41 (FLAG, STORE_x, NAME_x, NUMBER_x) values ('S', 3, 'C', 'C3');

insert into F42 (STORE_x, NAME_x, NUMBER_x) values (1, 'A', 'A1');
insert into F42 (STORE_x, NAME_x, NUMBER_x) values (2, 'B', 'B2');
insert into F42 (STORE_x, NAME_x, NUMBER_x) values (3, 'C', 'C3');
insert into F42 (STORE_x, NAME_x, NUMBER_x) values (4, 'D', 'D4');

Update Statement Using Exists:

update  F41 t1
set     flag = 'P'
WHERE   EXISTS (SELECT  1
                FROM    F42 t2
                WHERE   t2.STORE_X  = t1.STORE_X
                AND     t2.NAME_X   = t1.NAME_X
                AND     t2.NUMBER_X = t1.NUMBER_X);    

Hope this Helps!

Answer 3

You can do this with nothing more fancy than a WHERE clause:

UPDATE TESTDATA.F41
    SET FLAG = 'P' 
    WHERE EXISTS (SELECT 1
                  FROM TESTDATE.F42
                  WHERE F41.NAME = F42.NAME AND F41.NUMBER = F42.NUMBER
                 );

This is standard SQL and should work in any database.

Answer 4

UPDATE TESTDATA.F41 SET F41.FLAG='P' 
FROM TESTDATA.F42
WHERE F41.NAME = F42.NAME AND F41.NUMBER = F42.NUMBER

Answer 5

UPDATE TESTDATA.F41
SET FLAG = 'P' 
WHERE EXISTS (SELECT 1
              FROM TESTDATE.F42
              WHERE F41.NAME = F42.NAME AND F41.NUMBER = F42.NUMBER
             );