modify characteristics data to include all 288s in modeldata
Currently, we bring characteristics into the modeling data via
LEFT JOIN CCAOSFCHARS AS C ON C.PIN=H.HD_PIN AND C.TAX_YEAR=H.TAX_YEAR
However, we know that CCAOSFCHARS is pre-modified to account for 288s. A 288 is a major improvement in a structure that is exempt from taxation for a period of time. For the purposes of modeling, however, excluding 288 characteristics undermines the performance of our models. The table ADDCHARS contains 288 information.
Goal: modify this SQL query so that the characteristics of the property include 288s for those 288s that are still active.