Help needed with QUERY

[philosophology]

REPLACE INTO (SELECT * FROM tblA WHERE lblA='$lblA') (lbl😎 VALUES ('$lblB')

Here is what I am trying to do:

There are 2 tables: tblA, tblB
I want to change the value of one of the entries in tblA by doing:
1. searching for the row that matches the $lblA ....

(SELECT * FROM tblA WHERE lblA='$lblA')

2. take that row in 1, change the value od the column denoted by lblB to $lblB....

REPLACE INTO .... (lbl😎 VALUES ('$lblB')

Please guide me :">
Thanks

[downisme]

UPDATE tblA SET column = 'value' WHERE column = '$lblA'

update record in table A and set the column to a value WHERE tableAColumn = value
***If the WHERE Condition is not unique, it will update multiple rows with that....

if your trying to do nested queries you can do it like....

UPDATE tblA SET columnA = 'value' WHERE column = (SELECT colB FROM tableB WHERE col = "value")

Thats just basic you need to be more clear on your intent cause its confusing what relationship with tableA to TableB