Implement select

* Does not support formatted print. * Need to check aliasing and case ignoring.
yeonwooKim · Nov 23, 2016 · f255086 · f255086
1 parent 365f822
commit f255086
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Showing 10 changed files with 577 additions and 128 deletions.
diff --git a/src/Attribute.java b/src/Attribute.java
@@ -12,7 +12,9 @@ public class Attribute implements Serializable {
     private int foreignKey;
     private boolean isNotNull;
     private int index;
-    private String tablename;
+    private String tablename = null;
+    private String tableAlias = null;
+    private String alias = null;
 
     public Attribute(Type attrType, String attrName) {
         this.attrType = attrType;
@@ -44,6 +46,8 @@ public int getForeignKey() {
     }
 
     public String getTablename() { return tablename; }
+    public String getTableAlias() { return tableAlias; }
+    public String getAlias() { return alias; }
 
     public void setForeignKey(int f) {
         foreignKey = f;
@@ -60,6 +64,8 @@ public void setNotNull() {
     public void setIndex(int index) { this.index = index; }
 
     public void setTablename(String tablename) { this.tablename = tablename; }
+    public void setTableAlias(String tableAlias) { this.tableAlias = tableAlias; }
+    public void setAlias(String alias) { this.alias = alias; }
 
     public int getIndex() { return index; }
 }
diff --git a/src/Berkeley.java b/src/Berkeley.java
@@ -120,14 +120,10 @@ public void insertRecord(String tablename, Record rec) {
     private static boolean recordHasValue(DatabaseEntry data, ArrayList<Integer> index, ArrayList<Value> values) {
         try {
             Record rec = (Record) deserialize(data.getData());
-            Iterator<Integer> it = index.iterator();
-            int i = 0;
-            while (it.hasNext()) {
-                if (!values.get(i).equals(rec.getIndex(it.next())))
-                    return false;
-                i ++;
-            }
-            return true;
+            ArrayList<Value> values1 = rec.getIndices(index);
+            if (values1.equals(values))
+                return true;
+            return false;
         } catch (Exception e) {
             return false;
         }
@@ -196,13 +192,21 @@ private void cascadeToNull(String tablename, ArrayList<Integer> index, ArrayList
                 return;
             }
             Record rec = (Record) deserialize(data.getData());
-            if (rec.getIndices(index).equals(values));
+            if (rec.getIndices(index).equals(values)) {
                 recordToNull(rec, index);
+                cursor.delete();
+                data = new DatabaseEntry(serialize(rec));
+                db.put(null, key, data);
+            }
 
             while (cursor.get(key, data, Get.NEXT_DUP, null) != null) {
                 rec = (Record) deserialize(data.getData());
-                if (rec.getIndices(index).equals(values))
+                if (rec.getIndices(index).equals(values)) {
                     recordToNull(rec, index);
+                    cursor.delete();
+                    data = new DatabaseEntry(serialize(rec));
+                    db.put(null, key, data);
+                }
             }
             cursor.close();
         } catch (Exception e) {
@@ -332,4 +336,75 @@ public Message removeRecord(String tablename, BooleanValueExpression bve) {
             return null;
         }
     }
+
+    private boolean incrCursor(String[] tables, ArrayList<Cursor> cursors, ArrayList<DatabaseEntry> datas, int size) {
+        DatabaseEntry key = new DatabaseEntry(), data = new DatabaseEntry();
+        if (cursors.get(size - 1).get(key, data, Get.NEXT_DUP, null) != null) {
+            datas.set(size - 1, data);
+            return true;
+        }
+        else {
+            if (size  == 1) {
+                return false;
+            }
+            else {
+                try {
+                    key = new DatabaseEntry(tables[size - 1].getBytes("UTF-8"));
+                    cursors.get(size - 1).getSearchKey(key, data, LockMode.DEFAULT);
+                    datas.set(size - 1, data);
+                    return incrCursor(tables, cursors, datas, size - 1);
+                } catch (Exception e) {
+                    return false;
+                }
+            }
+        }
+    }
+
+    public void select(String tablename, BooleanValueExpression bve, ArrayList<Integer> projection) {
+        String[] tables = tablename.split("@");
+        ArrayList<Cursor> cursors = new ArrayList<>();
+        ArrayList<DatabaseEntry> datas = new ArrayList<>();
+        try {
+            for (int i = 0; i < tables.length; i++) {
+                Cursor cursor = db.openCursor(null, null);
+                DatabaseEntry key;
+                DatabaseEntry data = null;
+                key = new DatabaseEntry(tables[i].getBytes("UTF-8"));
+                data = new DatabaseEntry();
+                OperationStatus os = cursor.getSearchKey(key, data, LockMode.DEFAULT);
+                if (os != OperationStatus.SUCCESS) {
+                    throw new Exception();
+                }
+                cursors.add(cursor);
+                datas.add(data);
+            }
+            do {
+                ArrayList<Value> arr = new ArrayList<>();
+                Iterator<DatabaseEntry> it = datas.iterator();
+                while (it.hasNext()) {
+                    Record rec = (Record) deserialize(it.next().getData());
+                    arr.addAll(rec.getValues());
+                }
+                Record newRecord = new Record(arr);
+                if (bve == null || bve.eval(DBManager.getDBManager().findTable(tablename), newRecord)) {
+                    //TODO: print these values
+                    ArrayList<Value> res = (projection == null) ? newRecord.getValues() : newRecord.getIndices(projection);
+                    Iterator<Value> itPrint = res.iterator();
+                    while (itPrint.hasNext()) {
+                        itPrint.next().print();
+                    }
+                    System.out.println();
+                }
+            } while(incrCursor(tables, cursors, datas, tables.length));
+            Iterator<Cursor> it = cursors.iterator();
+            while (it.hasNext()) {
+                it.next().close();
+            }
+        } catch (Exception e) {
+            Iterator<Cursor> it = cursors.iterator();
+            while (it.hasNext()) {
+                it.next().close();
+            }
+        }
+    }
 }
diff --git a/src/DBManager.java b/src/DBManager.java
@@ -38,6 +38,16 @@ public Table findTable(String tablename) {
         return null;
     }
 
+    public Table findTableAlias(String alias) {
+        Iterator<Table> it = tables.iterator();
+        while (it.hasNext()) {
+            Table n = it.next();
+            if (n.getAlias().equalsIgnoreCase(alias))
+                return n;
+        }
+        return null;
+    }
+
     public void addTable(Table t) {
         tables.add(t);
     } // Called when CREATE TABLE requested

diff --git a/src/MessageName.java b/src/MessageName.java
@@ -27,10 +27,13 @@ public enum MessageName {
     INSERT_COLUMN_EXISTENCE, // column name
     INSERT_DUPLICATE_PRIMARY_KEY,
     INSERT_REFERENTIAL_INTEGRITY,
-    SELECT, INSERT_SUCCESS,
+    SELECT_SUCCESS,
+    INSERT_SUCCESS,
     DELETE_SUCCESS,
     WHERE_INCOMPARABLE,
     WHERE_TABLE_NOT_SPECIFIED,
     WHERE_COLUMN_NOT_EXIST,
-    WHERE_AMBIGUOUS_REFERENCE
+    WHERE_AMBIGUOUS_REFERENCE,
+    SELECT_TABLE_EXISTENCE_ERROR,
+    SELECT_COLUMN_RESOLVE_ERROR
 }
diff --git a/src/MessagePrinter.java b/src/MessagePrinter.java
@@ -11,6 +11,9 @@ private static void dropTableFailed() {
         System.out.print("Drop table has failed: ");
     }
     private static void insertionFailed() { System.out.print("Insertion has failed: "); }
+    private static void selectionFailed() {
+        System.out.print("Selection has failed: ");
+    }
     public static void printMessage(Message m)
     {
         MessageName q = m.getMessagename();
@@ -91,9 +94,17 @@ public static void printMessage(Message m)
                 System.out.println("Char length should be over 0");
                 break;
 
-            case SELECT:
-                System.out.println("\'SELECT\' requested");
+            case SELECT_SUCCESS:
+                break;
+            case SELECT_COLUMN_RESOLVE_ERROR:
+                selectionFailed();
+                System.out.println("fail to resolve \'[" + n + "]\'");
                 break;
+            case SELECT_TABLE_EXISTENCE_ERROR:
+                selectionFailed();
+                System.out.println("\'[" + n + "]\' does not exist");
+                break;
+
             case INSERT_SUCCESS:
                 System.out.println("The row is inserted");
                 break;

diff --git a/src/Record.java b/src/Record.java
@@ -13,6 +13,10 @@ public Record() {
        values = new ArrayList<>();
     }
 
+    public Record(ArrayList<Value> values) {
+        this.values = values;
+    }
+
     public Value getIndex(int i) {
         return values.get(i);
     }
@@ -26,6 +30,10 @@ public ArrayList<Value> getIndices(ArrayList<Integer> arr) {
         return ret;
     }
 
+    public ArrayList<Value> getValues() {
+        return values;
+    }
+
     public void setIndex(int i, Value v) { values.set(i, v); }
 
     private static void addForeignKeyList(ArrayList<ArrayList<Value>> foreignKey, int index, Value v,