Null is converted to empty string when writing to database.

Hi Varsha,

From my experience, Appian will always write a blank value instead of null of data type Text.  The workarounds I have used in the past are:

1. Following the writeToDataStoreEntity node, use a Query Database node with a statement such as UPDATE table SET col1 = NULL WHERE col1 = ''
2. If this particular value is always blank/null, you can exclude it from your CDT so that Appian does not replace is with a blank value.

I realize these solutions are less than ideal, and I do wish Appian would treat text fields the same as other data types and retain a NULL value in the database.  I am curious if anyone else has come up with a better solution.

Brad

An easy workaround to query entities with empty ( null ) text fields is to use the following query filter:

a!queryFilter(
    field: "name",
    operator: "in",
    value: {"", null}
)

Thanks Philip. For some reason this didn't work for me when comparing to null, but it pointed me in the right direction. I ended up using the "queryLogicalExpression" function to do something like this:

a!queryLogicalExpression(
  operator: "OR",
  filters: {
    a!queryFilter(
      field: "name",
      operator: "is null"
    ),
    a!queryFilter(
      field: "name",
      operator: "in",
      value: {""}
    )
  }
)