diff --git a/sql/core/src/main/scala/org/apache/spark/sql/Column.scala b/sql/core/src/main/scala/org/apache/spark/sql/Column.scala index 7e1f1d83cb3de..bd1669b6dba69 100644 --- a/sql/core/src/main/scala/org/apache/spark/sql/Column.scala +++ b/sql/core/src/main/scala/org/apache/spark/sql/Column.scala @@ -464,7 +464,15 @@ class Column(val expr: Expression) extends Logging { * @group expr_ops * @since 1.3.0 */ - def <=> (other: Any): Column = withExpr { EqualNullSafe(expr, lit(other).expr) } + def <=> (other: Any): Column = withExpr { + val right = lit(other).expr + if (this.expr == right) { + logWarning( + s"Constructing trivially true equals predicate, '${this.expr} <=> $right'. " + + "Perhaps you need to use aliases.") + } + EqualNullSafe(expr, right) + } /** * Equality test that is safe for null values.