[CALCITE-5708] SUBSTRING validation error if any parameter is a NULL …

…literal Close apache#3211
QAQ-Jun · Jul 5, 2023 · 1b11d99 · 1b11d99
1 parent f1d0316
commit 1b11d99
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Showing 3 changed files with 26 additions and 4 deletions.
diff --git a/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java b/core/src/main/java/org/apache/calcite/sql/fun/SqlSubstringFunction.java
@@ -44,10 +44,10 @@
  * Definition of the "SUBSTRING" builtin SQL function.
  */
 public class SqlSubstringFunction extends SqlFunction {
-  /** Type checker for 3 argument calls. Put the STRING_NUMERIC_NUMERIC checker
+  /** Type checker for 3 argument calls. Put the STRING_INTEGER_INTEGER checker
    * first because almost every other type can be coerced to STRING. */
   private static final SqlSingleOperandTypeChecker CHECKER3 =
-      OperandTypes.STRING_NUMERIC_NUMERIC
+      OperandTypes.STRING_INTEGER_INTEGER
           .or(OperandTypes.STRING_STRING_STRING);
 
   //~ Constructors -----------------------------------------------------------
@@ -74,7 +74,8 @@ public class SqlSubstringFunction extends SqlFunction {
     case 3:
       return "{0}({1} FROM {2} FOR {3})";
     default:
-      throw new AssertionError();
+      throw new AssertionError("Incorrect " + getName() + " signature, operands "
+          + "count = " + operandsCount);
     }
   }
 
@@ -121,7 +122,7 @@ public class SqlSubstringFunction extends SqlFunction {
           return false;
         }
       }
-      if (!SqlTypeUtil.inSameFamily(t1, t2)) {
+      if (!SqlTypeUtil.inSameFamilyOrNull(t1, t2)) {
         if (throwOnFailure) {
           throw callBinding.newValidationSignatureError();
         }

diff --git a/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java b/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
@@ -1040,6 +1040,12 @@ void testDyadicCollateOperator() {
         .columnType("VARCHAR(1) NOT NULL");
     expr("substring('a', 1, '3')")
         .columnType("VARCHAR(1) NOT NULL");
+
+    // Correctly processed null string and params.
+    expr("SUBSTRING(NULL FROM 1 FOR 2)").ok();
+    expr("SUBSTRING('text' FROM 1 FOR NULL)").ok();
+    expr("SUBSTRING('text' FROM NULL FOR 2)").ok();
+    expr("SUBSTRING('text' FROM NULL)").ok();
   }
 
   @Test void testSubstringFails() {

diff --git a/core/src/test/resources/sql/functions.iq b/core/src/test/resources/sql/functions.iq
@@ -938,5 +938,20 @@ table(AUX.TBLFUN_IDENTITY(3)) as t3(v);
 
 !ok
 
+# SUBSTRING
+-- returns 'null'
+select SUBSTRING(NULL FROM 1 FOR 2);
+select SUBSTRING('text' FROM 1 FOR NULL);
+select SUBSTRING('text' FROM NULL FOR 2);
+select SUBSTRING(s FROM i FOR l) FROM (VALUES ('abc', NULL, 2)) AS t (s, i, l);
+select SUBSTRING('text' FROM NULL);
++--------+
+| EXPR$0 |
++--------+
+|        |
++--------+
+(1 row)
+
+!ok
 
 # End functions.iq