[CALCITE-6156] Add ENDSWITH, STARTSWITH functions (enabled in Postgre…

…s, Snowflake libraries)

core/src/main/java/org/apache/calcite/sql/SqlKind.java

@@ -806,6 +806,12 @@ public enum SqlKind {
   /** {@code SUBSTR} function (PostgreSQL semantics). */
   SUBSTR_POSTGRESQL,
 
+  /** {@code ENDS_WITH} function. */
+  ENDS_WITH,
+
+  /** {@code STARTS_WITH} function. */
+  STARTS_WITH,
+
   /** Call to a function using JDBC function syntax. */
   JDBC_FN,
 

core/src/main/java/org/apache/calcite/sql/dialect/SnowflakeSqlDialect.java

@@ -17,7 +17,11 @@
 package org.apache.calcite.sql.dialect;
 
 import org.apache.calcite.avatica.util.Casing;
+import org.apache.calcite.sql.SqlCall;
 import org.apache.calcite.sql.SqlDialect;
+import org.apache.calcite.sql.SqlWriter;
+import org.apache.calcite.sql.fun.SqlLibraryOperators;
+import org.apache.calcite.sql.parser.SqlParserPos;
 
 /**
  * A <code>SqlDialect</code> implementation for the Snowflake database.
@@ -36,6 +40,24 @@ public SnowflakeSqlDialect(Context context) {
     super(context);
   }
 
+  @Override public void unparseCall(final SqlWriter writer, final SqlCall call, final int leftPrec,
+      final int rightPrec) {
+    switch (call.getKind()) {
+    case ENDS_WITH:
+      SqlCall endsWithCall = SqlLibraryOperators.ENDSWITH
+          .createCall(SqlParserPos.ZERO, call.getOperandList());
+      super.unparseCall(writer, endsWithCall, leftPrec, rightPrec);
+      break;
+    case STARTS_WITH:
+      SqlCall startsWithCall = SqlLibraryOperators.STARTSWITH
+          .createCall(SqlParserPos.ZERO, call.getOperandList());
+      super.unparseCall(writer, startsWithCall, leftPrec, rightPrec);
+      break;
+    default:
+      super.unparseCall(writer, call, leftPrec, rightPrec);
+    }
+  }
+
   @Override public boolean supportsApproxCountDistinct() {
     return true;
   }

core/src/main/java/org/apache/calcite/sql/fun/SqlLibrary.java

@@ -71,6 +71,8 @@ public enum SqlLibrary {
   /** A collection of operators that are in PostgreSQL but not in standard
    * SQL. */
   POSTGRESQL("p", "postgresql"),
+  /** A collection of operators that are in Snowflake but not in standard SQL. */
+  SNOWFLAKE("f", "snowflake"),
   /** A collection of operators that are in Apache Spark but not in standard
    * SQL. */
   SPARK("s", "spark");
@@ -97,7 +99,7 @@ public List<SqlLibrary> children() {
     switch (this) {
     case ALL:
       return ImmutableList.of(BIG_QUERY, CALCITE, HIVE, MSSQL, MYSQL, ORACLE,
-          POSTGRESQL, SPARK);
+          POSTGRESQL, SNOWFLAKE, SPARK);
     default:
       return ImmutableList.of();
     }

core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java

@@ -67,6 +67,7 @@
 import static org.apache.calcite.sql.fun.SqlLibrary.MYSQL;
 import static org.apache.calcite.sql.fun.SqlLibrary.ORACLE;
 import static org.apache.calcite.sql.fun.SqlLibrary.POSTGRESQL;
+import static org.apache.calcite.sql.fun.SqlLibrary.SNOWFLAKE;
 import static org.apache.calcite.sql.fun.SqlLibrary.SPARK;
 import static org.apache.calcite.util.Static.RESOURCE;
 
@@ -360,17 +361,25 @@ static RelDataType deriveTypeSplit(SqlOperatorBinding operatorBinding,
           OperandTypes.STRING_INTEGER_OPTIONAL_INTEGER,
           SqlFunctionCategory.STRING);
 
-  /** The "ENDS_WITH(value1, value2)" function (BigQuery). */
-  @LibraryOperator(libraries = {BIG_QUERY})
-  public static final SqlFunction ENDS_WITH =
-      SqlBasicFunction.create("ENDS_WITH", ReturnTypes.BOOLEAN_NULLABLE,
-          OperandTypes.STRING_SAME_SAME, SqlFunctionCategory.STRING);
+  /** The "ENDS_WITH(value1, value2)" function (BigQuery, PostgreSQL). */
+  @LibraryOperator(libraries = {BIG_QUERY, POSTGRESQL})
+  public static final SqlBasicFunction ENDS_WITH =
+      SqlBasicFunction.create(SqlKind.ENDS_WITH, ReturnTypes.BOOLEAN_NULLABLE,
+          OperandTypes.STRING_SAME_SAME);
 
-  /** The "STARTS_WITH(value1, value2)" function (BigQuery). */
-  @LibraryOperator(libraries = {BIG_QUERY})
-  public static final SqlFunction STARTS_WITH =
-      SqlBasicFunction.create("STARTS_WITH", ReturnTypes.BOOLEAN_NULLABLE,
-          OperandTypes.STRING_SAME_SAME, SqlFunctionCategory.STRING);
+  /** The "ENDSWITH(value1, value2)" function (Snowflake). */
+  @LibraryOperator(libraries = {SNOWFLAKE})
+  public static final SqlFunction ENDSWITH = ENDS_WITH.withName("ENDSWITH");
+
+  /** The "STARTS_WITH(value1, value2)" function (BigQuery, PostgreSQL). */
+  @LibraryOperator(libraries = {BIG_QUERY, POSTGRESQL})
+  public static final SqlBasicFunction STARTS_WITH =
+      SqlBasicFunction.create(SqlKind.STARTS_WITH, ReturnTypes.BOOLEAN_NULLABLE,
+          OperandTypes.STRING_SAME_SAME);
+
+  /** The "STARTSWITH(value1, value2)" function (Snowflake). */
+  @LibraryOperator(libraries = {SNOWFLAKE})
+  public static final SqlFunction STARTSWITH = STARTS_WITH.withName("STARTSWITH");
 
   /** BigQuery's "SUBSTR(string, position [, substringLength ])" function. */
   @LibraryOperator(libraries = {BIG_QUERY})

core/src/main/java/org/apache/calcite/sql2rel/StandardConvertletTable.java

@@ -133,6 +133,8 @@ private StandardConvertletTable() {
     addAlias(SqlStdOperatorTable.PERCENT_REMAINDER, SqlStdOperatorTable.MOD);
     addAlias(SqlLibraryOperators.IFNULL, SqlLibraryOperators.NVL);
     addAlias(SqlLibraryOperators.REGEXP_SUBSTR, SqlLibraryOperators.REGEXP_EXTRACT);
+    addAlias(SqlLibraryOperators.ENDSWITH, SqlLibraryOperators.ENDS_WITH);
+    addAlias(SqlLibraryOperators.STARTSWITH, SqlLibraryOperators.STARTS_WITH);
 
     // Register convertlets for specific objects.
     registerOp(SqlStdOperatorTable.CAST, this::convertCast);

core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java

@@ -6662,6 +6662,40 @@ private void checkLiteral2(String expression, String expected) {
     sql(sql).withMysql().ok(expectedMysql);
   }
 
+  /** Test case for
+   * <a href="https://issues.apache.org/jira/browse/CALCITE-6156">[CALCITE-6156]
+   * Add ENDSWITH, STARTSWITH functions (enabled in Postgres, Snowflake libraries)</a>. */
+  @Test void testSnowflakeStartsWith() {
+    final String query = "select startswith(\"brand_name\", 'a')\n"
+        + "from \"product\"";
+    final String expectedBigQuery = "SELECT STARTS_WITH(brand_name, 'a')\n"
+        + "FROM foodmart.product";
+    final String expectedPostgres = "SELECT STARTS_WITH(\"brand_name\", 'a')\n"
+        + "FROM \"foodmart\".\"product\"";
+    final String expectedSnowflake = "SELECT STARTSWITH(\"brand_name\", 'a')\n"
+        + "FROM \"foodmart\".\"product\"";
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withBigQuery().ok(expectedBigQuery);
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withPostgresql().ok(expectedPostgres);
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withSnowflake().ok(expectedSnowflake);
+  }
+
+  /** Test case for
+   * <a href="https://issues.apache.org/jira/browse/CALCITE-6156">[CALCITE-6156]
+   * Add ENDSWITH, STARTSWITH functions (enabled in Postgres, Snowflake libraries)</a>. */
+  @Test void testSnowflakeEndsWith() {
+    final String query = "select endswith(\"brand_name\", 'a')\n"
+        + "from \"product\"";
+    final String expectedBigQuery = "SELECT ENDS_WITH(brand_name, 'a')\n"
+        + "FROM foodmart.product";
+    final String expectedPostgres = "SELECT ENDS_WITH(\"brand_name\", 'a')\n"
+        + "FROM \"foodmart\".\"product\"";
+    final String expectedSnowflake = "SELECT ENDSWITH(\"brand_name\", 'a')\n"
+        + "FROM \"foodmart\".\"product\"";
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withBigQuery().ok(expectedBigQuery);
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withPostgresql().ok(expectedPostgres);
+    sql(query).withLibrary(SqlLibrary.SNOWFLAKE).withSnowflake().ok(expectedSnowflake);
+  }
+
   @Test void testSubstringInSpark() {
     final String query = "select substring(\"brand_name\" from 2) "
         + "from \"product\"\n";

core/src/test/java/org/apache/calcite/util/UtilTest.java

@@ -951,16 +951,16 @@ private List<Integer> makeConsList(int start, int end) {
 
     assertThat(SqlLibrary.expand(ImmutableList.of(a)),
         hasToString("[ALL, BIG_QUERY, CALCITE, HIVE, MSSQL, MYSQL, ORACLE, "
-            + "POSTGRESQL, SPARK]"));
+            + "POSTGRESQL, SNOWFLAKE, SPARK]"));
     assertThat(SqlLibrary.expand(ImmutableList.of(a, c)),
         hasToString("[ALL, BIG_QUERY, CALCITE, HIVE, MSSQL, MYSQL, ORACLE, "
-            + "POSTGRESQL, SPARK]"));
+            + "POSTGRESQL, SNOWFLAKE, SPARK]"));
     assertThat(SqlLibrary.expand(ImmutableList.of(c, a)),
         hasToString("[CALCITE, ALL, BIG_QUERY, HIVE, MSSQL, MYSQL, ORACLE, "
-            + "POSTGRESQL, SPARK]"));
+            + "POSTGRESQL, SNOWFLAKE, SPARK]"));
     assertThat(SqlLibrary.expand(ImmutableList.of(c, o, a)),
         hasToString("[CALCITE, ORACLE, ALL, BIG_QUERY, HIVE, MSSQL, MYSQL, "
-            + "POSTGRESQL, SPARK]"));
+            + "POSTGRESQL, SNOWFLAKE, SPARK]"));
     assertThat(SqlLibrary.expand(ImmutableList.of(o, c, o)),
         hasToString("[ORACLE, CALCITE]"));
 

site/_docs/reference.md

@@ -2629,6 +2629,7 @@ The 'C' (compatibility) column contains value:
 * '*' for all libraries,
 * 'b' for Google BigQuery ('fun=bigquery' in the connect string),
 * 'c' for Apache Calcite ('fun=calcite' in the connect string),
+* 'f' for Snowflake ('fun=snowflake' in the connect string),
 * 'h' for Apache Hive ('fun=hive' in the connect string),
 * 'm' for MySQL ('fun=mysql' in the connect string),
 * 'q' for Microsoft SQL Server ('fun=mssql' in the connect string),
@@ -2728,7 +2729,8 @@ BigQuery's type system uses confusingly different names for types and functions:
 | b | DATE_TRUNC(date, timeUnit)                     | Truncates *date* to the granularity of *timeUnit*, rounding to the beginning of the unit
 | o | DECODE(value, value1, result1 [, valueN, resultN ]* [, default ]) | Compares *value* to each *valueN* value one by one; if *value* is equal to a *valueN*, returns the corresponding *resultN*, else returns *default*, or NULL if *default* is not specified
 | p | DIFFERENCE(string, string)                     | Returns a measure of the similarity of two strings, namely the number of character positions that their `SOUNDEX` values have in common: 4 if the `SOUNDEX` values are same and 0 if the `SOUNDEX` values are totally different
-| b | ENDS_WITH(string1, string2)                    | Returns whether *string2* is a suffix of *string1*
+| f | ENDSWITH(string1, string2)                     | Returns whether *string2* is a suffix of *string1*
+| b p | ENDS_WITH(string1, string2)                  | Equivalent to `ENDSWITH(string1, string2)`
 | o | EXTRACT(xml, xpath, [, namespaces ])           | Returns the XML fragment of the element or elements matched by the XPath expression. The optional namespace value that specifies a default mapping or namespace mapping for prefixes, which is used when evaluating the XPath expression
 | o | EXISTSNODE(xml, xpath, [, namespaces ])        | Determines whether traversal of a XML document using a specified xpath results in any nodes. Returns 0 if no nodes remain after applying the XPath traversal on the document fragment of the element or elements matched by the XPath expression. Returns 1 if any nodes remain. The optional namespace value that specifies a default mapping or namespace mapping for prefixes, which is used when evaluating the XPath expression.
 | m | EXTRACTVALUE(xml, xpathExpr))                  | Returns the text of the first text node which is a child of the element or elements matched by the XPath expression.
@@ -2825,7 +2827,8 @@ BigQuery's type system uses confusingly different names for types and functions:
 | s | SOUNDEX(string)                                | Returns the phonetic representation of *string*; return original *string* if *string* is encoded with multi-byte encoding such as UTF-8
 | m | SPACE(integer)                                 | Returns a string of *integer* spaces; returns an empty string if *integer* is less than 1
 | b | SPLIT(string [, delimiter ])                   | Returns the string array of *string* split at *delimiter* (if omitted, default is comma).  If the *string* is empty it returns an empty array, otherwise, if the *delimiter* is empty, it returns an array containing the original *string*.
-| b | STARTS_WITH(string1, string2)                  | Returns whether *string2* is a prefix of *string1*
+| f | STARTSWITH(string1, string2)                   | Returns whether *string2* is a prefix of *string1*
+| b p | STARTS_WITH(string1, string2)                | Equivalent to `STARTSWITH(string1, string2)`
 | m | STRCMP(string, string)                         | Returns 0 if both of the strings are same and returns -1 when the first argument is smaller than the second and 1 when the second one is smaller than the first one
 | b p | STRPOS(string, substring)                    | Equivalent to `POSITION(substring IN string)`
 | b m o p | SUBSTR(string, position [, substringLength ]) | Returns a portion of *string*, beginning at character *position*, *substringLength* characters long. SUBSTR calculates lengths using characters as defined by the input character set