mysql update column with value from another table
In addition to this answer if you need to change tableB.value according to tableA.value dynamically you can do for example:
UPDATE tableBINNER JOIN tableA ON tableB.name = tableA.nameSET tableB.value = IF(tableA.value > 0, tableA.value, tableB.value)WHERE tableA.name = 'Joe'
you need to join the two tables:
for instance you want to copy the value of name from tableA into tableB where they have the same ID
UPDATE tableB t1 INNER JOIN tableA t2 ON t1.id = t2.idSET t1.name = t2.name WHERE t2.name = 'Joe'UPDATE 1
UPDATE tableB t1 INNER JOIN tableA t2 ON t1.id = t2.idSET t1.name = t2.name UPDATE 2
UPDATE tableB t1 INNER JOIN tableA t2 ON t1.name = t2.nameSET t1.value = t2.value
Second possibility is,
UPDATE TableB SET TableB.value = ( SELECT TableA.value FROM TableA WHERE TableA.name = TableB.name);