fix comments

apache · Apr 22, 2024 · e04933a · e04933a
1 parent 76f073f
commit e04933a
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Showing 3 changed files with 37 additions and 27 deletions.
diff --git a/...-core/src/main/java/org/apache/doris/nereids/rules/expression/ExpressionOptimization.java b/...-core/src/main/java/org/apache/doris/nereids/rules/expression/ExpressionOptimization.java
@@ -22,13 +22,13 @@
 import org.apache.doris.nereids.rules.expression.rules.DateFunctionRewrite;
 import org.apache.doris.nereids.rules.expression.rules.DistinctPredicatesRule;
 import org.apache.doris.nereids.rules.expression.rules.ExtractCommonFactorRule;
-import org.apache.doris.nereids.rules.expression.rules.NotEqualToLength;
 import org.apache.doris.nereids.rules.expression.rules.NullSafeEqualToEqual;
 import org.apache.doris.nereids.rules.expression.rules.OrToIn;
 import org.apache.doris.nereids.rules.expression.rules.SimplifyComparisonPredicate;
 import org.apache.doris.nereids.rules.expression.rules.SimplifyDecimalV3Comparison;
 import org.apache.doris.nereids.rules.expression.rules.SimplifyInPredicate;
 import org.apache.doris.nereids.rules.expression.rules.SimplifyRange;
+import org.apache.doris.nereids.rules.expression.rules.StringEqualToLength;
 import org.apache.doris.nereids.rules.expression.rules.TopnToMax;
 
 import com.google.common.collect.ImmutableList;
@@ -53,7 +53,7 @@ public class ExpressionOptimization extends ExpressionRewrite {
                 CaseWhenToIf.INSTANCE,
                 TopnToMax.INSTANCE,
                 NullSafeEqualToEqual.INSTANCE,
-                NotEqualToLength.INSTANCE
+                StringEqualToLength.INSTANCE
             )
     );
     private static final ExpressionRuleExecutor EXECUTOR = new ExpressionRuleExecutor(OPTIMIZE_REWRITE_RULES);

diff --git a/...es/expression/rules/NotEqualToLength.java → ...expression/rules/StringEqualToLength.java b/...es/expression/rules/NotEqualToLength.java → ...expression/rules/StringEqualToLength.java
@@ -20,41 +20,38 @@
 import org.apache.doris.nereids.rules.expression.ExpressionPatternMatcher;
 import org.apache.doris.nereids.rules.expression.ExpressionPatternRuleFactory;
 import org.apache.doris.nereids.trees.expressions.EqualPredicate;
+import org.apache.doris.nereids.trees.expressions.EqualTo;
 import org.apache.doris.nereids.trees.expressions.Expression;
-import org.apache.doris.nereids.trees.expressions.GreaterThan;
-import org.apache.doris.nereids.trees.expressions.Not;
 import org.apache.doris.nereids.trees.expressions.functions.scalar.Length;
 import org.apache.doris.nereids.trees.expressions.literal.IntegerLiteral;
-import org.apache.doris.nereids.trees.expressions.literal.StringLiteral;
+import org.apache.doris.nereids.trees.expressions.literal.StringLikeLiteral;
 
 import com.google.common.collect.ImmutableList;
 
 import java.util.List;
 
 /**
- * Rewrite rule to convert NOT EQUAL(string, "") to GREATERTHAN(string, 0)
+ * Rewrite rule to convert EQUAL(string, "") to length(string, 0)
  * For example:
- * string <> ""  ==>  length(string) > 0
+ * string == ""  ==>  length(string) == 0
  */
-public class NotEqualToLength implements ExpressionPatternRuleFactory {
+public class StringEqualToLength implements ExpressionPatternRuleFactory {
 
-    public static NotEqualToLength INSTANCE = new NotEqualToLength();
+    public static StringEqualToLength INSTANCE = new StringEqualToLength();
 
     @Override
     public List<ExpressionPatternMatcher<? extends Expression>> buildRules() {
         return ImmutableList.of(
-            matchesTopType(Not.class).then(NotEqualToLength::rewrite)
+            matchesTopType(EqualPredicate.class).then(StringEqualToLength::rewrite)
         );
     }
 
-    private static Expression rewrite(Not not) {
-        Expression expr = not;
-        if (not.getArgument(0) instanceof EqualPredicate) {
-            EqualPredicate equalPredicate = (EqualPredicate) not.getArgument(0);
-            if (equalPredicate.getArgument(0).getDataType().isStringType()
-                    && equalPredicate.getArgument(1).equals(new StringLiteral(""))) {
-                expr = new GreaterThan(new Length(equalPredicate.getArgument(0)), new IntegerLiteral(0), false);
-            }
+    private static Expression rewrite(EqualPredicate equalPredicate) {
+        Expression expr = equalPredicate;
+        if (equalPredicate.getArgument(0).getDataType().isStringType()
+                && equalPredicate.getArgument(1) instanceof StringLikeLiteral
+                && ((StringLikeLiteral) equalPredicate.getArgument(1)).getStringValue().equals("")) {
+            expr = new EqualTo(new Length(equalPredicate.getArgument(0)), new IntegerLiteral(0));
         }
         return expr;
     }

diff --git a/..._p0/expression/not_equal_to_length.groovy → .../expression/string_equal_to_length.groovy b/..._p0/expression/not_equal_to_length.groovy → .../expression/string_equal_to_length.groovy
@@ -15,49 +15,62 @@
 // specific language governing permissions and limitations
 // under the License.
 
-suite("test_not_equal_to_length") {
+suite("string_equal_to_length") {
     sql 'set enable_nereids_planner=true'
     sql 'set enable_fallback_to_original_planner=false'
 
-    sql 'drop table if exists test_not_equal_to_length;'
+    sql 'drop table if exists test_string_equal_to_length;'
 
-    sql '''create table test_not_equal_to_length (k0 int, k1 string, k2 varchar, k3 char(5)) distributed by hash(k0) buckets 3 properties('replication_num' = '1');'''
+    sql '''create table test_string_equal_to_length (k0 int, k1 string, k2 varchar, k3 char(5)) distributed by hash(k0) buckets 3 properties('replication_num' = '1');'''
 
     // for string type
     sql '''
     select k1
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k1 <> "";
     '''
     def res = sql '''
     explain rewritten plan select k1
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k1 <> "";
     '''
     assertTrue(res.toString().contains("length"))
 
     // for varchar type
     sql '''
     select k2
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k2 <> "";
     '''
     def res1 = sql '''
     explain rewritten plan select k2
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k2 <> "";
     '''
     assertTrue(res1.toString().contains("length"))
 
     sql '''
     select k3
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k3 <> "";
     '''
     def res2 = sql '''
     explain rewritten plan select k3
-    from test_not_equal_to_length
+    from test_string_equal_to_length
     where k3 <> "";
     '''
     assertTrue(res2.toString().contains("length"))
+
+    // for equal
+    sql '''
+    select k1
+    from test_string_equal_to_length
+    where k1 == "";
+    '''
+    def res3 = sql '''
+    explain rewritten plan select k1
+    from test_string_equal_to_length
+    where k1 == "";'''
+    assertTrue(res3.toString().contains("length"))
+
 }