mysql - Check table_A before updating table_B -

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i'm trying make query checks if field 'field_a' in 'table_a' '0' , if is, update 'field_b' in 'table_b' '10'.

i have no idea if possible. have little experience mysql , i'm trying things out. if is, i'd know how done.

update table_b set field_b = 10 exists (select 1 table_a field_a = 0)

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