recognize CallableStatement parameter names with leading '@'

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerCallableStatement.java

@@ -1451,6 +1451,15 @@ public NClob getNClob(String parameterName) throws SQLException {
         if (paramNames != null)
             l = paramNames.size();
 
+        // handle `@name` as well as `name`, since `@name` is what's returned 
+        // by DatabaseMetaData#getProcedureColumns
+        String columnNameWithoutAtSign = null;
+        if (columnName.startsWith("@")) {
+            columnNameWithoutAtSign = columnName.substring(1, columnName.length());
+        } else {
+            columnNameWithoutAtSign = columnName;
+        }
+
         // In order to be as accurate as possible when locating parameter name
         // indexes, as well as be deterministic when running on various client
         // locales, we search for parameter names using the following scheme:
@@ -1465,7 +1474,7 @@ public NClob getNClob(String parameterName) throws SQLException {
         for (i = 0; i < l; i++) {
             String sParam = paramNames.get(i);
             sParam = sParam.substring(1, sParam.length());
-            if (sParam.equals(columnName)) {
+            if (sParam.equals(columnNameWithoutAtSign)) {
                 matchPos = i;
                 break;
             }
@@ -1477,7 +1486,7 @@ public NClob getNClob(String parameterName) throws SQLException {
             for (i = 0; i < l; i++) {
                 String sParam = paramNames.get(i);
                 sParam = sParam.substring(1, sParam.length());
-                if (sParam.equalsIgnoreCase(columnName)) {
+                if (sParam.equalsIgnoreCase(columnNameWithoutAtSign)) {
                     matchPos = i;
                     break;
                 }

src/test/java/com/microsoft/sqlserver/jdbc/callablestatement/CallableStatementTest.java

@@ -1,9 +1,12 @@
 package com.microsoft.sqlserver.jdbc.callablestatement;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
 
+import java.sql.CallableStatement;
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.sql.Types;
@@ -17,6 +20,7 @@
 
 import com.microsoft.sqlserver.jdbc.SQLServerCallableStatement;
 import com.microsoft.sqlserver.jdbc.SQLServerDataSource;
+import com.microsoft.sqlserver.jdbc.SQLServerException;
 import com.microsoft.sqlserver.testframework.AbstractTest;
 import com.microsoft.sqlserver.testframework.Utils;
 
@@ -28,6 +32,7 @@ public class CallableStatementTest extends AbstractTest {
     private static String tableNameGUID = "uniqueidentifier_Table";
     private static String outputProcedureNameGUID = "uniqueidentifier_SP";
     private static String setNullProcedureName = "CallableStatementTest_setNull_SP";
+    private static String inputParamsProcedureName = "CallableStatementTest_inputParams_SP";
 
     private static Connection connection = null;
     private static Statement stmt = null;
@@ -45,10 +50,12 @@ public static void setupTest() throws SQLException {
         Utils.dropTableIfExists(tableNameGUID, stmt);
         Utils.dropProcedureIfExists(outputProcedureNameGUID, stmt);
         Utils.dropProcedureIfExists(setNullProcedureName, stmt);
+        Utils.dropProcedureIfExists(inputParamsProcedureName, stmt);
 
         createGUIDTable();
         createGUIDStoredProcedure();
-        createSetNullPreocedure();
+        createSetNullProcedure();
+        createInputParamsProcedure();
     }
 
     /**
@@ -133,6 +140,46 @@ public void getSetNullWithTypeVarchar() throws SQLException {
         }
     }
 
+
+    /**
+     * recognize parameter names with and without leading '@'
+     * 
+     * @throws SQLException
+     */
+    @Test
+    public void inputParamsTest() throws SQLException {
+        String call = "{CALL " + inputParamsProcedureName + " (?,?)}";
+        ResultSet rs = null;
+
+        // the historical way: no leading '@', parameter names respected (not positional)
+        CallableStatement cs1 = connection.prepareCall(call);
+        cs1.setString("p2", "bar");
+        cs1.setString("p1", "foo");
+        rs = cs1.executeQuery();
+        rs.next();
+        assertEquals("foobar", rs.getString(1));
+
+        // the "new" way: leading '@', parameter names still respected (not positional)
+        CallableStatement cs2 = connection.prepareCall(call);
+        cs2.setString("@p2", "world!");
+        cs2.setString("@p1", "Hello ");
+        rs = cs2.executeQuery();
+        rs.next();
+        assertEquals("Hello world!", rs.getString(1));
+
+        // sanity check: unrecognized parameter name
+        CallableStatement cs3 = connection.prepareCall(call);
+        try {
+            cs3.setString("@whatever", "junk");
+            fail("SQLServerException should have been thrown");
+        } catch (SQLServerException sse) {
+            if (!sse.getMessage().startsWith("Parameter @whatever was not defined")) {
+                fail("Unexpected content in exception message");
+            }
+        }
+
+    }
+
     /**
      * Cleanup after test
      * 
@@ -143,6 +190,7 @@ public static void cleanup() throws SQLException {
         Utils.dropTableIfExists(tableNameGUID, stmt);
         Utils.dropProcedureIfExists(outputProcedureNameGUID, stmt);
         Utils.dropProcedureIfExists(setNullProcedureName, stmt);
+        Utils.dropProcedureIfExists(inputParamsProcedureName, stmt);
 
         if (null != stmt) {
             stmt.close();
@@ -162,7 +210,20 @@ private static void createGUIDTable() throws SQLException {
         stmt.execute(sql);
     }
 
-    private static void createSetNullPreocedure() throws SQLException {
+    private static void createSetNullProcedure() throws SQLException {
         stmt.execute("create procedure " + setNullProcedureName + " (@p1 nvarchar(255), @p2 nvarchar(255) output) as select @p2=@p1 return 0");
     }
+
+    private static void createInputParamsProcedure() throws SQLException {
+        String sql = 
+                "CREATE PROCEDURE [dbo].[CallableStatementTest_inputParams_SP] " +
+                "    @p1 nvarchar(max) = N'parameter1', " +
+                "    @p2 nvarchar(max) = N'parameter2' " +
+                "AS " +
+                "BEGIN " +
+                "    SET NOCOUNT ON; " +
+                "    SELECT @p1 + @p2 AS result; " +
+                "END ";
+        stmt.execute(sql);
+    }
 }