function overloading

h2/src/main/org/h2/command/Parser.java

@@ -10,7 +10,9 @@ import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.sql.SQLException;
 import java.text.Collator;
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 
 import org.h2.api.Trigger;
 import org.h2.command.ddl.AlterIndexRename;
@@ -1810,15 +1812,17 @@ public class Parser {
             // ( CALL "java.lang.Math.sqrt"(2.0) )
             throw Message.getSQLException(ErrorCode.FUNCTION_NOT_FOUND_1, name);
         }
-        int paramCount = functionAlias.getParameterCount();
-        Expression[] args = new Expression[paramCount];
-        for (int i = 0; i < args.length; i++) {
-            if (i > 0) {
+        Expression[] args;
+        List argList = new ArrayList();
+        int numArgs = 0;
+        while (!readIf(")")) {
+            if (numArgs++ > 0) {
                 read(",");
             }
-            args[i] = readExpression();
+            argList.add(readExpression());
         }
-        read(")");
+        args = new Expression[numArgs];
+        argList.toArray(args);
         JavaFunction func = new JavaFunction(functionAlias, args);
         return func;
     }

h2/src/main/org/h2/constant/ErrorCode.java

@@ -1092,6 +1092,22 @@ public class ErrorCode {
      */
     public static final int ROLES_AND_RIGHT_CANNOT_BE_MIXED = 90072;
 
+    /**
+     * The error with code <code>90073</code> is thrown when trying to create
+     * an alias for a Java method, if two methods exists in this class that have
+     * this name and the same number of parameters. Example:
+     * <pre>
+     * CREATE ALIAS GET_LONG FOR 
+     *      "java.lang.Long.getLong";
+     * </pre>
+     * Correct:
+     * <pre>
+     * CREATE ALIAS GET_LONG FOR 
+     *      "java.lang.Long.getLong(java.lang.String, java.lang.Long)";
+     * </pre>
+     */
+    public static final int METHODS_MUST_HAVE_DIFFERENT_PARAMETER_COUNTS_2 = 90073;
+    
     /**
      * The error with code <code>90074</code> is thrown when
      * trying to grant a role that has already been granted.

h2/src/main/org/h2/expression/JavaFunction.java

@@ -23,19 +23,21 @@ import org.h2.value.ValueResultSet;
 public class JavaFunction extends Expression implements FunctionCall {
 
     private FunctionAlias functionAlias;
+    private FunctionAlias.JavaMethod javaMethod;
     private Expression[] args;
 
-    public JavaFunction(FunctionAlias functionAlias, Expression[] args) {
+    public JavaFunction(FunctionAlias functionAlias, Expression[] args) throws SQLException {
         this.functionAlias = functionAlias;
+        this.javaMethod = functionAlias.findJavaMethod(args);
         this.args = args;
     }
 
     public Value getValue(Session session) throws SQLException {
-        return functionAlias.getValue(session, args, false);
+        return javaMethod.getValue(session, args, false);
     }
 
     public int getType() {
-        return functionAlias.getDataType();
+        return javaMethod.getDataType();
     }
 
     public void mapColumns(ColumnResolver resolver, int level) throws SQLException {
@@ -102,11 +104,11 @@ public class JavaFunction extends Expression implements FunctionCall {
     }
 
     public int getParameterCount() throws SQLException {
-        return functionAlias.getParameterCount();
+        return javaMethod.getParameterCount();
     }
 
     public ValueResultSet getValueForColumnList(Session session, Expression[] args) throws SQLException {
-        Value v = functionAlias.getValue(session, args, true);
+        Value v = javaMethod.getValue(session, args, true);
         return v == ValueNull.INSTANCE ? null : (ValueResultSet) v;
     }
 
@@ -135,7 +137,7 @@ public class JavaFunction extends Expression implements FunctionCall {
     }
 
     public int getCost() {
-        int cost = functionAlias.hasConnectionParam() ? 25 : 5;
+        int cost = javaMethod.hasConnectionParam() ? 25 : 5;
         for (int i = 0; i < args.length; i++) {
             cost += args[i].getCost();
         }

h2/src/main/org/h2/jdbc/JdbcDatabaseMetaData.java

@@ -493,13 +493,15 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
 
     /**
      * Gets the list of procedures. The result set is sorted by PROCEDURE_SCHEM,
-     * and PROCEDURE_NAME.
+     * PROCEDURE_NAME, and NUM_INPUT_PARAMS. There are potentially multiple
+     * procedures with the same name, each with a different number of input
+     * parameters.
      * 
      * <ul>
      * <li>1 PROCEDURE_CAT (String) catalog </li>
      * <li>2 PROCEDURE_SCHEM (String) schema </li>
      * <li>3 PROCEDURE_NAME (String) name </li>
-     * <li>4 NUM_INPUT_PARAMS (int) for future use, always 0 </li>
+     * <li>4 NUM_INPUT_PARAMS (int) the number of arguments </li>
      * <li>5 NUM_OUTPUT_PARAMS (int) for future use, always 0 </li>
      * <li>6 NUM_RESULT_SETS (int) for future use, always 0 </li>
      * <li>7 REMARKS (String) description </li>
@@ -507,7 +509,7 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
      * (procedureNoResult or procedureReturnsResult) </li>
      * </ul>
      * 
-     * @return an empty result set
+     * @return the procedures.
      * @throws SQLException if the connection is closed
      */
     public ResultSet getProcedures(String catalog, String schemaPattern,
@@ -524,7 +526,7 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "ALIAS_CATALOG PROCEDURE_CAT, "
                     + "ALIAS_SCHEMA PROCEDURE_SCHEM, "
                     + "ALIAS_NAME PROCEDURE_NAME, "
-                    + "ZERO() NUM_INPUT_PARAMS, "
+                    + "COLUMN_COUNT NUM_INPUT_PARAMS, "
                     + "ZERO() NUM_OUTPUT_PARAMS, "
                     + "ZERO() NUM_RESULT_SETS, "
                     + "REMARKS, "
@@ -533,7 +535,7 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "WHERE ALIAS_CATALOG LIKE ? "
                     + "AND ALIAS_SCHEMA LIKE ? "
                     + "AND ALIAS_NAME LIKE ? "
-                    + "ORDER BY PROCEDURE_SCHEM, PROCEDURE_NAME");
+                    + "ORDER BY PROCEDURE_SCHEM, PROCEDURE_NAME, NUM_INPUT_PARAMS");
             prep.setString(1, getCatalogPattern(catalog));
             prep.setString(2, getSchemaPattern(schemaPattern));
             prep.setString(3, getPattern(procedureNamePattern));
@@ -544,23 +546,28 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
     }
 
     /**
-     * Gets the list of procedure columns.
+     * Gets the list of procedure columns. The result set is sorted by
+     * PROCEDURE_SCHEM, PROCEDURE_NAME, NUM_INPUT_PARAMS, and POS.
+     * There are potentially multiple procedures with the same name, each with a
+     * different number of input parameters.
      * 
      * <ul>
-     * <li>1 PROCEDURE_CAT (String) catalog
-     * </li><li>2 PROCEDURE_SCHEM (String) schema
-     * </li><li>3 PROCEDURE_NAME (String) name
-     * </li><li>4 COLUMN_NAME (String) column name
-     * </li><li>5 COLUMN_TYPE (short) column type
-     * </li><li>6 DATA_TYPE (short) sql type
-     * </li><li>7 TYPE_NAME (String) type name
-     * </li><li>8 PRECISION (int) precision
-     * </li><li>9 LENGTH (int) length
-     * </li><li>10 SCALE (short) scale
-     * </li><li>11 RADIX (int) always 10
-     * </li><li>12 NULLABLE (short) nullable
-     * </li><li>13 REMARKS (String) description
-     * </li></ul>
+     * <li>1 PROCEDURE_CAT (String) catalog </li>
+     * <li>2 PROCEDURE_SCHEM (String) schema </li>
+     * <li>3 PROCEDURE_NAME (String) name </li>
+     * <li>4 COLUMN_NAME (String) column name </li>
+     * <li>5 COLUMN_TYPE (short) column type </li>
+     * <li>6 DATA_TYPE (short) sql type </li>
+     * <li>7 TYPE_NAME (String) type name </li>
+     * <li>8 PRECISION (int) precision </li>
+     * <li>9 LENGTH (int) length </li>
+     * <li>10 SCALE (short) scale </li>
+     * <li>11 RADIX (int) always 10 </li>
+     * <li>12 NULLABLE (short) nullable </li>
+     * <li>13 REMARKS (String) description </li>
+     * <li>14 NUM_INPUT_PARAMS (int) the parameter count </li>
+     * <li>15 POS (int) the parameter index </li>
+     * </ul>
      * 
      * @throws SQLException if the connection is closed
      */
@@ -589,12 +596,15 @@ public class JdbcDatabaseMetaData extends TraceObject implements DatabaseMetaDat
                     + "SCALE, "
                     + "RADIX, "
                     + "NULLABLE, "
-                    + "REMARKS "
+                    + "REMARKS, "
+                    + "COLUMN_COUNT NUM_INPUT_PARAMS, "
+                    + "POS "
                     + "FROM INFORMATION_SCHEMA.FUNCTION_COLUMNS "
                     + "WHERE ALIAS_CATALOG LIKE ? "
                     + "AND ALIAS_SCHEMA LIKE ? "
                     + "AND ALIAS_NAME LIKE ? "
-                    + "AND COLUMN_NAME LIKE ?");
+                    + "AND COLUMN_NAME LIKE ? "
+                    + "ORDER BY PROCEDURE_SCHEM, PROCEDURE_NAME, NUM_INPUT_PARAMS, POS");
             prep.setString(1, getCatalogPattern(catalog));
             prep.setString(2, getSchemaPattern(schemaPattern));
             prep.setString(3, getPattern(procedureNamePattern));

h2/src/main/org/h2/res/_messages_de.properties

@@ -93,7 +93,7 @@
 90070=Rolle {0} nicht gefunden
 90071=Benutzer or Rolle {0} nicht gefunden
 90072=Rollen und Rechte k\u00F6nnen nicht gemischt werden
-90073=Recht nicht gefunden
+90073=Java Methoden m\u00FCssen eine unterschiedliche Anzahl Parameter aufweisen\: {0} und {1}
 90074=Rolle {0} bereits zugewiesen
 90075=Feld ist Teil eines Indexes {0}
 90076=Funktions-Alias {0} besteht bereits

h2/src/main/org/h2/res/_messages_en.properties

@@ -93,7 +93,7 @@
 90070=Role {0} not found
 90071=User or role {0} not found
 90072=Roles and rights cannot be mixed
-90073=Right not found
+90073=Matching Java methods must have different parameter counts\: {0} and {1}
 90074=Role {0} already granted
 90075=Column is part of the index {0}
 90076=Function alias {0} already exists

h2/src/main/org/h2/res/_messages_ja.properties

@@ -93,7 +93,7 @@
 90070=\u30ED\u30FC\u30EB {0} \u304C\u898B\u3064\u304B\u308A\u307E\u305B\u3093
 90071=\u30E6\u30FC\u30B6\u3001\u307E\u305F\u306F\u30ED\u30FC\u30EB {0} \u304C\u898B\u3064\u304B\u308A\u307E\u305B\u3093
 90072=\u30ED\u30FC\u30EB\u3068\u6A29\u9650\u306F\u6DF7\u5728\u3067\u304D\u307E\u305B\u3093
-90073=\u6A29\u9650\u304C\u898B\u3064\u304B\u308A\u307E\u305B\u3093
+90073=\#Matching Java methods must have different parameter counts\: {0} and {1}
 90074=\u30ED\u30FC\u30EB {0} \u306F\u3059\u3067\u306B\u8A31\u53EF\u3055\u308C\u3066\u3044\u307E\u3059
 90075=\u5217\u306F\u30A4\u30F3\u30C7\u30C3\u30AF\u30B9 {0} \u306E\u4E00\u90E8\u3067\u3059
 90076=\u95A2\u6570\u306E\u5225\u540D {0} \u306F\u3059\u3067\u306B\u5B58\u5728\u3057\u307E\u3059

h2/src/main/org/h2/res/_messages_pl.properties

@@ -93,7 +93,7 @@
 90070=Rola {0} nie istnieje
 90071=Uzytkownik lub Rola User {0} nie istnieje
 90072=Role i prawa nie moga byc mieszane
-90073=Prawo nie istnieje
+90073=\#Matching Java methods must have different parameter counts\: {0} and {1}
 90074=Rola {0} juz przyznana
 90075=Kolumna jest czescia indeksu {0}
 90076=Alias funkcji {0} juz istnieje

h2/src/main/org/h2/res/_messages_pt_br.properties

@@ -93,7 +93,7 @@
 90070=Regra {0} n\u00E3o foi encontrada
 90071=Usu\u00E1rio ou regra {0} n\u00E3o foram encontrados
 90072=Regras e permiss\u00F5es n\u00E3o podem ser combinados
-90073=Permiss\u00E3o n\u00E3o encontrada
+90073=\#Matching Java methods must have different parameter counts\: {0} and {1}
 90074=Regra {0} j\u00E1 foi concedida
 90075=A coluna faz parte do \u00EDndice {0}
 90076=Nome alternativo da fun\u00E7\u00E3o {0} j\u00E1 existe

h2/src/main/org/h2/res/help.csv

@@ -362,6 +362,8 @@ and may optionally include the parameter classes as in ""java.lang.Integer.parse
 Admin rights are required to execute this command.
 If the first parameter of the Java function is a java.sql.Connection, then
 the current to the database is provided. This connection must not be closed.
+Functions may be overloaded, that means multiple functions with the same name may exist.
+In this case, each function must have a different parameter count.
 ","
 CREATE ALIAS MY_SQRT FOR ""java.lang.Math.sqrt""
 "

h2/src/main/org/h2/table/MetaTable.java

@@ -264,6 +264,7 @@ public class MetaTable extends Table {
                     "ALIAS_NAME",
                     "JAVA_CLASS",
                     "JAVA_METHOD",
+                    "COLUMN_COUNT INT",
                     "POS INT",
                     "COLUMN_NAME",
                     "DATA_TYPE INT",
@@ -990,7 +991,10 @@ public class MetaTable extends Table {
             ObjectArray aliases = database.getAllFunctionAliases();
             for (int i = 0; i < aliases.size(); i++) {
                 FunctionAlias alias = (FunctionAlias) aliases.get(i);
-                int returnsResult = alias.getDataType() == Value.NULL ? DatabaseMetaData.procedureNoResult
+                FunctionAlias.JavaMethod[] methods = alias.getJavaMethods();
+                for (int j = 0; j < methods.length; j++) {
+                    FunctionAlias.JavaMethod method = methods[j];
+                    int returnsResult = method.getDataType() == Value.NULL ? DatabaseMetaData.procedureNoResult
                             : DatabaseMetaData.procedureReturnsResult;
                     add(rows, new String[] {
                             // ALIAS_CATALOG
@@ -1004,9 +1008,9 @@ public class MetaTable extends Table {
                             // JAVA_METHOD
                             alias.getJavaMethodName(), 
                             // DATA_TYPE
-                        ""+DataType.convertTypeToSQLType(alias.getDataType()), 
+                            ""+DataType.convertTypeToSQLType(method.getDataType()), 
                             // COLUMN_COUNT INT
-                        ""+ alias.getColumnClasses().length, 
+                            ""+ method.getColumnClasses().length, 
                             // RETURNS_RESULT SMALLINT
                             ""+ returnsResult, 
                             // REMARKS
@@ -1015,6 +1019,7 @@ public class MetaTable extends Table {
                             "" + alias.getId()
                     });
                 }
+            }
             ObjectArray aggregates = database.getAllAggregates();
             for (int i = 0; i < aggregates.size(); i++) {
                 UserAggregate agg = (UserAggregate) aggregates.get(i);
@@ -1048,9 +1053,12 @@ public class MetaTable extends Table {
             ObjectArray aliases = database.getAllFunctionAliases();
             for (int i = 0; i < aliases.size(); i++) {
                 FunctionAlias alias = (FunctionAlias) aliases.get(i);
-                Class[] columns = alias.getColumnClasses();
-                for (int j = 0; j < columns.length; j++) {
-                    Class clazz = columns[j];
+                FunctionAlias.JavaMethod[] methods = alias.getJavaMethods();
+                for (int j = 0; j < methods.length; j++) {
+                    FunctionAlias.JavaMethod method = methods[j];
+                    Class[] columns = method.getColumnClasses();
+                    for (int k = 0; k < columns.length; k++) {
+                        Class clazz = columns[k];
                         int type = DataType.getTypeFromClass(clazz);
                         DataType dt = DataType.getDataType(type);
                         int nullable = clazz.isPrimitive() ? DatabaseMetaData.columnNoNulls
@@ -1066,10 +1074,12 @@ public class MetaTable extends Table {
                                 alias.getJavaClassName(), 
                                 // JAVA_METHOD
                                 alias.getJavaMethodName(), 
+                                // COLUMN_COUNT
+                                "" + method.getParameterCount(),
                                 // POS INT
-                            "" + j, 
+                                "" + k, 
                                 // COLUMN_NAME
-                            "P" + (j+1), 
+                                "P" + (k+1), 
                                 // DATA_TYPE
                                 "" + DataType.convertTypeToSQLType(dt.type), 
                                 // TYPE_NAME
@@ -1089,6 +1099,7 @@ public class MetaTable extends Table {
                         });
                     }
                 }
+            }
             break;
         }
         case SCHEMATA: {