Table UPDATE statement

Venkatesh Babu wrote:

Hello,

I need to update few rows of a table (call it 't') and
need to set just one column col1 (out of around 100
columns... to be exact, our table has 116 columns).
The info about rows to be updated is present in
another table t2. t2 just contains 2 columns (row_key,
new value for col1).

What is the best way to perform update? Can't I give
an update statement like: UPDATE t set
col1=t2.new_col1_val where t1.row_key = t2.row_key
???? I think this kind of support is provided in db2,
but couldn't find how this can be done in postgres.

You're close:

UPDATE t1
SET col1 = t2.new_col1
FROM t2
WHERE t1.row_key = t2.row_key;

--
Alban Hertroys
MAG Productions

T: +31(0)53 4346874
F: +31(0)53 4346876
E: alban@magproductions.nl
W: http://www.magproductions.nl

Thanks very much :-) this saves lot of time for my
update statements ....

-Venkatesh

--- Alban Hertroys <alban@magproductions.nl> wrote:

Venkatesh Babu wrote:

Hello,

I need to update few rows of a table (call it 't')

and

need to set just one column col1 (out of around

100

columns... to be exact, our table has 116

columns).

The info about rows to be updated is present in
another table t2. t2 just contains 2 columns

(row_key,

new value for col1).

What is the best way to perform update? Can't I

give

an update statement like: UPDATE t set
col1=t2.new_col1_val where t1.row_key = t2.row_key
???? I think this kind of support is provided in

db2,

but couldn't find how this can be done in

postgres.

You're close:

UPDATE t1
SET col1 = t2.new_col1
FROM t2
WHERE t1.row_key = t2.row_key;

--
Alban Hertroys
MAG Productions

T: +31(0)53 4346874
F: +31(0)53 4346876
E: alban@magproductions.nl
W: http://www.magproductions.nl

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