[CALCITE-6182] Add LENGTH/LEN functions (enabled in Snowflake library)

tanclary · Dec 27, 2023 · 33fa420 · 33fa420
1 parent 8d624d9
commit 33fa420
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Showing 4 changed files with 24 additions and 3 deletions.
diff --git a/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java b/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java
@@ -274,8 +274,13 @@ private static SqlCall transformConvert(SqlValidator validator, SqlCall call) {
   @LibraryOperator(libraries = {BIG_QUERY})
   public static final SqlFunction IFNULL = NVL.withName("IFNULL");
 
+  /** The "LEN(string)" function. */
+  @LibraryOperator(libraries = {SNOWFLAKE})
+  public static final SqlFunction LEN =
+      SqlStdOperatorTable.CHAR_LENGTH.withName("LEN");
+
   /** The "LENGTH(string)" function. */
-  @LibraryOperator(libraries = {BIG_QUERY})
+  @LibraryOperator(libraries = {BIG_QUERY, SNOWFLAKE})
   public static final SqlFunction LENGTH =
       SqlStdOperatorTable.CHAR_LENGTH.withName("LENGTH");
 

diff --git a/core/src/main/java/org/apache/calcite/sql2rel/StandardConvertletTable.java b/core/src/main/java/org/apache/calcite/sql2rel/StandardConvertletTable.java
@@ -120,6 +120,8 @@ private StandardConvertletTable() {
 
     // Register aliases (operators which have a different name but
     // identical behavior to other operators).
+    addAlias(SqlLibraryOperators.LEN,
+        SqlStdOperatorTable.CHAR_LENGTH);
     addAlias(SqlLibraryOperators.LENGTH,
         SqlStdOperatorTable.CHAR_LENGTH);
     addAlias(SqlStdOperatorTable.CHARACTER_LENGTH,

diff --git a/site/_docs/reference.md b/site/_docs/reference.md
@@ -2765,7 +2765,8 @@ BigQuery's type system uses confusingly different names for types and functions:
 | m | JSON_STORAGE_SIZE(jsonValue)                   | Returns the number of bytes used to store the binary representation of *jsonValue*
 | b o | LEAST(expr [, expr ]* )                      | Returns the least of the expressions
 | b m p | LEFT(string, length)                       | Returns the leftmost *length* characters from the *string*
-| b | LENGTH(string)                                 | Equivalent to `CHAR_LENGTH(string)`
+| f | LEN(string)                                    | Equivalent to `CHAR_LENGTH(string)`
+| b f | LENGTH(string)                               | Equivalent to `CHAR_LENGTH(string)`
 | h s | LEVENSHTEIN(string1, string2)                | Returns the Levenshtein distance between *string1* and *string2*
 | b | LOG(numeric1 [, numeric2 ])                    | Returns the logarithm of *numeric1* to base *numeric2*, or base e if *numeric2* is not present
 | b o | LPAD(string, length [, pattern ])            | Returns a string or bytes value that consists of *string* prepended to *length* with *pattern*

diff --git a/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java b/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
@@ -4108,6 +4108,19 @@ static void checkRlikeFails(SqlOperatorFixture f) {
     f.checkNull("CHARACTER_LENGTH(cast(null as varchar(1)))");
   }
 
+  @Test void testLenFunc() {
+    final SqlOperatorFixture f0 = fixture().setFor(SqlLibraryOperators.LENGTH);
+    f0.checkFails("^length('hello')^",
+        "No match found for function signature LENGTH\\(<CHARACTER>\\)",
+        false);
+    final SqlOperatorFixture f = f0.withLibrary(SqlLibrary.SNOWFLAKE);
+    f.checkScalar("length('hello')", "5", "INTEGER NOT NULL");
+    f.checkScalar("length('')", "0", "INTEGER NOT NULL");
+    f.checkScalar("length(CAST('x' as CHAR(3)))", "3", "INTEGER NOT NULL");
+    f.checkScalar("length(CAST('x' as VARCHAR(4)))", "1", "INTEGER NOT NULL");
+    f.checkNull("length(CAST(NULL as CHAR(5)))");
+  }
+
   @Test void testLengthFunc() {
     final SqlOperatorFixture f0 = fixture().setFor(SqlLibraryOperators.LENGTH);
     f0.checkFails("^length('hello')^",
@@ -4122,7 +4135,7 @@ static void checkRlikeFails(SqlOperatorFixture f) {
       f.checkNull("length(CAST(NULL as CHAR(5)))");
     };
 
-    f0.forEachLibrary(list(SqlLibrary.BIG_QUERY), consumer);
+    f0.forEachLibrary(list(SqlLibrary.BIG_QUERY, SqlLibrary.SNOWFLAKE), consumer);
   }
 
   @Test void testOctetLengthFunc() {