IDENTIFIER not working in UPDATE

[marcuskw]

The following code works perfectly fine:

df = spark.createDataFrame([('A', 1), ('B', 2)])
df.createOrReplaceTempView('temp')

spark.sql("""
    SELECT
        IDENTIFIER(:col)
    FROM
        temp
""",
    args={
        "col": "_1"
    }
).display()

However if we instead want to do an UPDATE the same logic no longer functions:

spark.sql("""
    UPDATE
        temp
    SET
        IDENTIFIER(:col) = "C"
""",
    args={
        "col": "_1"
    }
)

Here we get the following error:
[PARSE_SYNTAX_ERROR] Syntax error at or near '(': missing EQ. SQLSTATE: 42601

Updating a temp table is not allowed, but used this quickly for a debug example.
When running the following UPDATE we get the correct error message "UPDATE TABLE is not supported temporarily.":

spark.sql("""
    UPDATE
        temp
    SET
        _1 = "C"
""")

[marcuskw]

Hi,

I wrote it in the bottom of my post that I know that updating a Temp table isn't allowed.
I used it as a quick example to illustrate the error message, but you get the same error message when updating a Delta Lake table.

The problem is the IDENTIFIER() syntax doesn't seem to function properly in an UPDATE statement. But works perfectly fine in a SELECT.

"Updating a temp table is not allowed, but used this quickly for a debug example.
When running the following UPDATE we get the correct error message "UPDATE TABLE is not supported temporarily.""

[Witold]

Hey @marcuskw the docs state that this is actually not supported. You can only use table names in an update statement:

---

• Table name of a MERGE, UPDATE, DELETE, INSERT, COPY INTO

[marcuskw]

Doesn't the docs say it is supported? (DML)

"A column or view referenced in a query. This includes queries embedded in a DDL or DML statement.
When using the identifier clause it may not be embedded within an identifier."

Here I'm referencing a column in an UPDATE statement.

spark.sql("""
    UPDATE
        temp
    SET
        IDENTIFIER(:col) = "C"
""",
    args={
        "col": "_1"
    }
)

[Witold]

Hey @marcuskw!

Sorry for the late response. IMHO the docs are not clear on that, but IDENTIFIER's are not supported in `SET` clauses. It works in `WHERE` clauses though (which of course will not help in your case):

spark.sql("""
    UPDATE
        temp
    SET
        _1 = "C"
    WHERE
        IDENTIFIER(:col) <> "C"
""",
    args={
        "col": "_1"
    }
)

 @Retired_mod You should update the docs accordingly.

[marcuskw · Accepted solution]

If it helps anyone else I found this article that described a few limitations:
https://community.databricks.com/t5/technical-blog/how-not-to-build-an-execute-immediate-demo/ba-p/8...