Comparing strings with numbers in the relational API

[krlmlr]

Behavior differs between relational and SQL. @Tmonster: why would that be?

Relational

duckdb <- asNamespace("duckdb")
con <- DBI::dbConnect(duckdb::duckdb())
experimental <- FALSE
invisible(DBI::dbExecute(con, "CREATE MACRO \"!=\"(x, y) AS x <> y"))
df1 <- data.frame(a = 1)

rel1 <- duckdb$rel_from_df(con, df1, experimental = experimental)
rel2 <- duckdb$rel_filter(
  rel1,
  list(
    duckdb$expr_function(
      "!=",
      list(
        duckdb$expr_reference("a"),
        if ("experimental" %in% names(formals(duckdb$expr_constant))) {
          duckdb$expr_constant("", experimental = experimental)
        } else {
          duckdb$expr_constant("")
        }
      )
    )
  )
)
rel2
#> DuckDB Relation: 
#> ---------------------
#> --- Relation Tree ---
#> ---------------------
#> Filter [!=(a, '')]
#>   r_dataframe_scan(0x152320908)
#> 
#> ---------------------
#> -- Result Columns  --
#> ---------------------
#> - a (DOUBLE)
duckdb$rel_to_altrep(rel2)
#> [1] a
#> <0 rows> (or 0-length row.names)

^{Created on 2023-11-16 with reprex v2.0.2}

SQL

✗ echo 'CREATE MACRO "!="(x, y) AS x <> y; SELECT 1.0 != '"''"' AS a' | build/debug/duckdb
Error: near line 1: Conversion Error: Could not convert string "" to DECIMAL(2,1)
✗ echo 'CREATE MACRO "!="(x, y) AS x <> y; SELECT '"''"' != 1.0 AS a' | build/debug/duckdb
Error: near line 1: Conversion Error: Could not convert string "" to DECIMAL(2,1)

[Tmonster]

Maybe the constant "" is getting registered as null?
I'll take a look

[krlmlr]

Will be fixed by extension.