Add a text as variable in a SQL query

[admin]

You are missing a single quote before " .. medida_param

You can use Lua multi-line string syntax to make it code more readable:

Code:

query = [[
  INSERT INTO test2 (instalacion, medida, usuario, valor)
  VALUES (
    ']] .. instalacion_param .. [[',
    ']] .. medida_param .. [[',
    ']] .. usuario_param .. [[',
    ]] .. valor_param .. [[
  )
]]

log(dbcon:execute(query))

Lua strings can be wrapped in single or double quotes. But MySQL expects parameters to be wrapped in single quotes.