[SPARK-48915][SQL][TESTS] Add some uncovered predicates(!=, <=, >, >=…

…) in test cases of `GeneratedSubquerySuite`

### What changes were proposed in this pull request?

This PR aims to add some predicates(!=, <=, >, >=) which are not covered in test cases of `GeneratedSubquerySuite`.

### Why are the changes needed?

Better coverage of current subquery tests in `GeneratedSubquerySuite`.
For more information about subqueries in `postgresq`, refer to:
https://www.postgresql.org/docs/current/functions-subquery.html#FUNCTIONS-SUBQUERY
https://www.postgresql.org/docs/current/functions-comparisons.html#ROW-WISE-COMPARISON

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Pass GA and Manual testing with `GeneratedSubquerySuite`.
![image](https://github.com/user-attachments/assets/4b265def-a7a9-405e-94ce-e9902efb79fa)

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#47386 from wayneguow/SPARK-48915.

Authored-by: Wei Guo <guow93@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>

connector/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/querytest/GeneratedSubquerySuite.scala

@@ -182,8 +182,11 @@ class GeneratedSubquerySuite extends DockerJDBCIntegrationSuite with QueryGenera
     } else {
       Seq()
     }
-    val isScalarSubquery = Seq(SubqueryType.ATTRIBUTE, SubqueryType.SCALAR_PREDICATE_EQUALS,
-      SubqueryType.SCALAR_PREDICATE_LESS_THAN).contains(subqueryType)
+    val isScalarSubquery = Seq(SubqueryType.ATTRIBUTE,
+      SubqueryType.SCALAR_PREDICATE_EQUALS, SubqueryType.SCALAR_PREDICATE_NOT_EQUALS,
+      SubqueryType.SCALAR_PREDICATE_LESS_THAN, SubqueryType.SCALAR_PREDICATE_LESS_THAN_OR_EQUALS,
+      SubqueryType.SCALAR_PREDICATE_GREATER_THAN,
+      SubqueryType.SCALAR_PREDICATE_GREATER_THAN_OR_EQUALS).contains(subqueryType)
     val subqueryOrganization = generateSubquery(
       innerTable, correlationConditions, isDistinct, operatorInSubquery, isScalarSubquery)
 
@@ -218,8 +221,16 @@ class GeneratedSubquerySuite extends DockerJDBCIntegrationSuite with QueryGenera
         val whereClausePredicate = subqueryType match {
           case SubqueryType.SCALAR_PREDICATE_EQUALS =>
             Equals(expr, Subquery(subqueryOrganization))
+          case SubqueryType.SCALAR_PREDICATE_NOT_EQUALS =>
+            NotEquals(expr, Subquery(subqueryOrganization))
           case SubqueryType.SCALAR_PREDICATE_LESS_THAN =>
             LessThan(expr, Subquery(subqueryOrganization))
+          case SubqueryType.SCALAR_PREDICATE_LESS_THAN_OR_EQUALS =>
+            LessThanOrEquals(expr, Subquery(subqueryOrganization))
+          case SubqueryType.SCALAR_PREDICATE_GREATER_THAN =>
+            GreaterThan(expr, Subquery(subqueryOrganization))
+          case SubqueryType.SCALAR_PREDICATE_GREATER_THAN_OR_EQUALS =>
+            GreaterThanOrEquals(expr, Subquery(subqueryOrganization))
           case SubqueryType.EXISTS => Exists(subqueryOrganization)
           case SubqueryType.NOT_EXISTS => Not(Exists(subqueryOrganization))
           case SubqueryType.IN => In(expr, subqueryOrganization)
@@ -294,7 +305,11 @@ class GeneratedSubquerySuite extends DockerJDBCIntegrationSuite with QueryGenera
         case SubqueryLocation.FROM => Seq(SubqueryType.RELATION)
         case SubqueryLocation.WHERE => Seq(
           SubqueryType.SCALAR_PREDICATE_LESS_THAN,
+          SubqueryType.SCALAR_PREDICATE_LESS_THAN_OR_EQUALS,
+          SubqueryType.SCALAR_PREDICATE_GREATER_THAN,
+          SubqueryType.SCALAR_PREDICATE_GREATER_THAN_OR_EQUALS,
           SubqueryType.SCALAR_PREDICATE_EQUALS,
+          SubqueryType.SCALAR_PREDICATE_NOT_EQUALS,
           SubqueryType.IN,
           SubqueryType.NOT_IN,
           SubqueryType.EXISTS,

sql/core/src/test/scala/org/apache/spark/sql/QueryGeneratorHelper.scala

@@ -82,9 +82,22 @@ trait QueryGeneratorHelper {
   case class Equals(expr: Expression, rightSideExpr: Expression) extends Predicate {
     override def toString: String = f"$expr = $rightSideExpr"
   }
+  case class NotEquals(expr: Expression, rightSideExpr: Expression) extends Predicate {
+    override def toString: String = f"$expr <> $rightSideExpr"
+  }
   case class LessThan(expr: Expression, rightSideExpr: Expression) extends Predicate {
     override def toString: String = f"$expr < $rightSideExpr"
   }
+  case class LessThanOrEquals(expr: Expression, rightSideExpr: Expression) extends Predicate {
+    override def toString: String = f"$expr <= $rightSideExpr"
+  }
+  case class GreaterThan(expr: Expression, rightSideExpr: Expression) extends Predicate {
+    override def toString: String = f"$expr > $rightSideExpr"
+  }
+  case class GreaterThanOrEquals(expr: Expression, rightSideExpr: Expression) extends Predicate {
+    override def toString: String = f"$expr >= $rightSideExpr"
+  }
+
   case class In(expr: Expression, inner: Operator)
     extends Predicate {
     override def toString: String = f"$expr IN ($inner)"
@@ -96,7 +109,10 @@ trait QueryGeneratorHelper {
     // Subquery to be treated as a Relation.
     val RELATION = Value
     // Subquery is a Predicate - types of predicate subqueries.
-    val SCALAR_PREDICATE_EQUALS, SCALAR_PREDICATE_LESS_THAN, IN, NOT_IN, EXISTS, NOT_EXISTS = Value
+    val SCALAR_PREDICATE_EQUALS, SCALAR_PREDICATE_NOT_EQUALS,
+      SCALAR_PREDICATE_LESS_THAN, SCALAR_PREDICATE_LESS_THAN_OR_EQUALS,
+      SCALAR_PREDICATE_GREATER_THAN, SCALAR_PREDICATE_GREATER_THAN_OR_EQUALS,
+      IN, NOT_IN, EXISTS, NOT_EXISTS = Value
   }
 
   trait SubqueryExpression extends Expression {