mysql update table field code example

Example 1: how to update an attribute in MySQL

UPDATE table_name
SET variable = 'changed field', variable = 'another changed field'
WHERE firstline_name = 1;

Example 2: mysql update table from another table

UPDATE tableB
INNER JOIN tableA ON tableB.name = tableA.name
SET tableB.value = IF(tableA.value > 0, tableA.value, tableB.value)
WHERE tableA.name = 'Joe'

Example 3: update all rows mysql

UPDATE tableName SET columnName = yourValue;
#to update multiple columns:
UPDATE tableName SET column1 = value1, column2 = value2; #and so on

Example 4: update table mysql

-- Things in brackets are optional
-- IGNORE modifier updates rows even if errors occur (ie: the rows that cause errors are simply not updated)
UPDATE [IGNORE] table_name 
SET 
    column_name1 = expr1,
    column_name2 = expr2,
    ...
[WHERE 
    condition]; -- WHERE tells us which rows to update based on said condition

Example 5: update column mysql with alter

ALTER TABLE table_name
  MODIFY column_name column_definition
    [ FIRST | AFTER column_name ];