Merge pull request #1155 from katzyn/merge_using

Fix different issues with MERGE USING

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

@@ -1168,11 +1168,33 @@ public class Parser {
         command.setOnCondition(condition);
         read(")");
 
-        if (readIfAll("WHEN", "MATCHED", "THEN")) {
+        boolean matched = parseWhenMatched(command);
+        if (parseWhenNotMatched(command) && !matched) {
+            parseWhenMatched(command);
+        }
+
+        setSQL(command, "MERGE", start);
+
+        // build and prepare the targetMatchQuery ready to test each rows
+        // existence in the target table (using source row to match)
+        StringBuilder targetMatchQuerySQL = new StringBuilder("SELECT _ROWID_ FROM ");
+        appendTableWithSchemaAndAlias(targetMatchQuerySQL, command.getTargetTable(),
+                command.getTargetTableFilter().getTableAlias());
+        targetMatchQuerySQL
+                .append(" WHERE ").append(command.getOnCondition().getSQL());
+        command.setTargetMatchQuery(
+                (Select) parse(targetMatchQuerySQL.toString()));
+
+        return command;
+    }
+
+    private boolean parseWhenMatched(MergeUsing command) {
+        if (!readIfAll("WHEN", "MATCHED", "THEN")) {
+            return false;
+        }
         int startMatched = lastParseIndex;
         if (readIf("UPDATE")) {
             Update updateCommand = new Update(session);
-                //currentPrepared = updateCommand;
             TableFilter filter = command.getTargetTableFilter();
             updateCommand.setTableFilter(filter);
             parseUpdateSetClause(updateCommand, filter, startMatched);
@@ -1186,34 +1208,29 @@ public class Parser {
             parseDeleteGivenTable(deleteCommand, null, startMatched);
             command.setDeleteCommand(deleteCommand);
         }
+        return true;
+    }
+
+    private boolean parseWhenNotMatched(MergeUsing command) {
+        if (!readIfAll("WHEN", "NOT", "MATCHED", "THEN")) {
+            return false;
         }
-        if (readIfAll("WHEN", "NOT", "MATCHED", "THEN")) {
         if (readIf("INSERT")) {
             Insert insertCommand = new Insert(session);
             insertCommand.setTable(command.getTargetTable());
             parseInsertGivenTable(insertCommand, command.getTargetTable());
             command.setInsertCommand(insertCommand);
         }
-        }
-
-        setSQL(command, "MERGE", start);
-
-        // build and prepare the targetMatchQuery ready to test each rows
-        // existence in the target table (using source row to match)
-        StringBuilder targetMatchQuerySQL = new StringBuilder("SELECT _ROWID_ FROM ");
-        appendTableWithSchemaAndAlias(targetMatchQuerySQL, command.getTargetTable(),
-                command.getTargetTableFilter().getTableAlias());
-        targetMatchQuerySQL
-                .append(" WHERE ").append(command.getOnCondition().getSQL());
-        command.setTargetMatchQuery(
-                (Select) parse(targetMatchQuerySQL.toString()));
-
-        return command;
+        return true;
     }
 
     private static void appendTableWithSchemaAndAlias(StringBuilder buff, Table table, String alias) {
+        if (table instanceof RangeTable) {
+            buff.append(table.getSQL());
+        } else {
             buff.append(quoteIdentifier(table.getSchema().getName()))
                 .append('.').append(quoteIdentifier(table.getName()));
+        }
         if (alias != null) {
             buff.append(" AS ").append(quoteIdentifier(alias));
         }
@@ -1460,7 +1477,7 @@ public class Parser {
                     table = new FunctionTable(mainSchema, session, expr, call);
                 }
             } else {
-                table = readTableOrView(tableName, true);
+                table = readTableOrView(tableName);
             }
         }
         ArrayList<String> derivedColumnNames = null;
@@ -5908,10 +5925,10 @@ public class Parser {
     }
 
     private Table readTableOrView() {
-        return readTableOrView(readIdentifierWithSchema(null), false);
+        return readTableOrView(readIdentifierWithSchema(null));
     }
 
-    private Table readTableOrView(String tableName, boolean allowDual) {
+    private Table readTableOrView(String tableName) {
         if (schemaName != null) {
             Table table = getSchema().resolveTableOrView(session, tableName);
             if (table != null) {
@@ -5934,7 +5951,7 @@ public class Parser {
                 }
             }
         }
-        if (allowDual && isDualTable(tableName)) {
+        if (isDualTable(tableName)) {
             return getDualTable(false);
         }
         throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableName);

h2/src/main/org/h2/command/dml/MergeUsing.java

@@ -113,7 +113,6 @@ public class MergeUsing extends Prepared {
     private Insert insertCommand;
     private String queryAlias;
     private int countUpdatedRows;
-    private Column[] sourceKeys;
     private Select targetMatchQuery;
     private final HashMap<Value, Integer> targetRowidsRemembered = new HashMap<>();
     private int sourceQueryRowNumber;
@@ -358,16 +357,6 @@ public class MergeUsing extends Prepared {
                     "No references to target columns found in ON clause:"
                             + targetTableFilter.toString());
         }
-        if (sourceKeys == null) {
-            HashSet<Column> sourceColumns = buildColumnListFromOnCondition(
-                    sourceTableFilter);
-            sourceKeys = sourceColumns.toArray(new Column[0]);
-        }
-        if (sourceKeys.length == 0) {
-            throw DbException.get(ErrorCode.COLUMN_NOT_FOUND_1,
-                    "No references to source columns found in ON clause:"
-                            + sourceTableFilter.toString());
-        }
 
         // only do the optimize now - before we have already gathered the
         // unoptimized column data

h2/src/test/org/h2/test/db/TestMergeUsing.java

@@ -245,7 +245,7 @@ public class TestMergeUsing extends TestBase implements Trigger {
                 GATHER_ORDERED_RESULTS_SQL,
                 "SELECT X AS ID, 'Marcy'||X||X AS NAME FROM SYSTEM_RANGE(2,2) UNION ALL " +
                 "SELECT X AS ID, 'Marcy'||X AS NAME FROM SYSTEM_RANGE(3,3)",
-                3, "No references to source columns found in ON clause");
+                3, "Duplicate key updated 3 rows at once, only 1 expected");
         // Insert does not insert correct values with respect to ON condition
         // (inserts ID value above 100, instead)
         testMergeUsingException(

h2/src/test/org/h2/test/scripts/dml/mergeUsing.sql

@@ -114,3 +114,38 @@ DROP TABLE SOURCE_TABLE;
 
 DROP TABLE DEST_TABLE;
 > ok
+
+CREATE TABLE TEST(C1 INT, C2 INT, C3 INT);
+> ok
+
+MERGE INTO TEST USING DUAL ON (C1 = 11 AND C2 = 21)
+    WHEN NOT MATCHED THEN INSERT (C1, C2, C3) VALUES (11, 21, 31)
+    WHEN MATCHED THEN UPDATE SET C3 = 31;
+> update count: 1
+
+MERGE INTO TEST USING DUAL ON (C1 = 11 AND C2 = 22)
+    WHEN NOT MATCHED THEN INSERT (C1, C2, C3) VALUES (11, 22, 32)
+    WHEN MATCHED THEN UPDATE SET C3 = 32;
+> update count: 1
+
+SELECT * FROM TEST ORDER BY C1, C2;
+> C1 C2 C3
+> -- -- --
+> 11 21 31
+> 11 22 32
+> rows (ordered): 2
+
+MERGE INTO TEST USING DUAL ON (C1 = 11 AND C2 = 21)
+    WHEN NOT MATCHED THEN INSERT (C1, C2, C3) VALUES (11, 21, 33)
+    WHEN MATCHED THEN UPDATE SET C3 = 33;
+> update count: 1
+
+SELECT * FROM TEST ORDER BY C1, C2;
+> C1 C2 C3
+> -- -- --
+> 11 21 33
+> 11 22 32
+> rows (ordered): 2
+
+DROP TABLE TEST;
+> ok