Merge pull request #1388 from katzyn/operation

Extract UnaryOperation from Operation and other changes

h2/src/docsrc/html/roadmap.html

@@ -79,7 +79,7 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Console: add accesskey to most important commands (A, AREA, BUTTON, INPUT, LABEL, LEGEND, TEXTAREA).
 </li><li>Test performance again with SQL Server, Oracle, DB2.
 </li><li>Test with Spatial DB in a box / JTS: http://www.opengeospatial.org/standards/sfs - OpenGIS Implementation Specification.
-</li><li>Write more tests and documentation for MVCC (Multi Version Concurrency Control).
+</li><li>Improve documentation of MVCC (Multi Version Concurrency Control).
 </li><li>Find a tool to view large text file (larger than 100 MB), with find, page up and down (like less), truncate before / after.
 </li><li>Implement, test, document XAConnection and so on.
 </li><li>Pluggable data type (for streaming, hashing, compression, validation, conversion, encryption).
@@ -219,7 +219,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Integrate spatial functions from http://geosysin.iict.ch/irstv-trac/wiki/H2spatial/Download
 </li><li>Cluster: hot deploy (adding a node at runtime).
 </li><li>Support DatabaseMetaData.insertsAreDetected: updatable result sets should detect inserts.
-</li><li>Oracle: support DECODE method (convert to CASE WHEN).
 </li><li>Native search: support "phrase search", wildcard search (* and ?), case-insensitive search, boolean operators, and grouping
 </li><li>Improve documentation of access rights.
 </li><li>Support opening a database that is in the classpath, maybe using a new file system. Workaround: detect jar file using getClass().getProtectionDomain().getCodeSource().getLocation().
@@ -256,7 +255,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>MySQL compatibility: real SQL statement for DESCRIBE TEST
 </li><li>Use a default delay of 1 second before closing a database.
 </li><li>Write (log) to system table before adding to internal data structures.
-</li><li>Support direct lookup for MIN and MAX when using WHERE (see todo.txt / Direct Lookup).
 </li><li>Support other array types (String[], double[]) in PreparedStatement.setObject(int, Object) (with test case).
 </li><li>Oracle compatibility: support NLS_DATE_FORMAT.
 </li><li>Support for Thread.interrupt to cancel running statements.
@@ -322,7 +320,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Doclet: convert tests in javadocs to a java class.
 </li><li>Doclet: format fields like methods, but support sorting by name and value.
 </li><li>Doclet: shrink the html files.
-</li><li>MySQL compatibility: support SET NAMES 'latin1' - See also http://code.google.com/p/h2database/issues/detail?id=56
 </li><li>Allow to scan index backwards starting with a value (to better support ORDER BY DESC).
 </li><li>Java Service Wrapper: try http://yajsw.sourceforge.net/
 </li><li>Batch parameter for INSERT, UPDATE, and DELETE, and commit after each batch. See also MySQL DELETE.
@@ -334,7 +331,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Sybase/DB2/Oracle compatibility: support out parameters in stored procedures - See http://code.google.com/p/h2database/issues/detail?id=83
 </li><li>Combine Server and Console tool (only keep Server).
 </li><li>Store the Lucene index in the database itself.
-</li><li>Oracle compatibility: support DECODE(x, ...).
 </li><li>MVCC: compare concurrent update behavior with PostgreSQL and Oracle.
 </li><li>HSQLDB compatibility: CREATE FUNCTION (maybe using a Function interface).
 </li><li>HSQLDB compatibility: support CALL "java.lang.Math.sqrt"(2.0)
@@ -346,7 +342,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Support =ANY(array) as in PostgreSQL. See also http://www.postgresql.org/docs/8.0/interactive/arrays.html
 </li><li>IBM DB2 compatibility: support PREVIOUS VALUE FOR sequence.
 </li><li>Compatibility: use different LIKE ESCAPE characters depending on the mode (disable for Derby, HSQLDB, DB2, Oracle, MSSQLServer).
-</li><li>Oracle compatibility: support CREATE SYNONYM table FOR schema.table.
 </li><li>FTP: document the server, including -ftpTask option to execute / kill remote processes
 </li><li>FTP: problems with multithreading?
 </li><li>FTP: implement SFTP / FTPS
@@ -410,7 +405,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Issue 178: Optimizer: index usage when both ascending and descending indexes are available.
 </li><li>Issue 179: Related subqueries in HAVING clause.
 </li><li>IBM DB2 compatibility: NOT NULL WITH DEFAULT. Similar to MySQL Mode.convertInsertNullToZero.
-</li><li>Creating primary key: always create a constraint.
 </li><li>Maybe use a different page layout: keep the data at the head of the page, and ignore the tail
     (don't store / read it). This may increase write / read performance depending on the file system.
 </li><li>Indexes of temporary tables are currently kept in-memory. Is this how it should be?
@@ -501,10 +495,10 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>PostgreSQL compatibility: UPDATE with FROM.
 </li><li>Issue 297: Oracle compatibility for "at time zone".
 </li><li>IBM DB2 compatibility: IDENTITY_VAL_LOCAL().
-</li><li>Support SQL/XML.
+</li><li>Support SQL/XML data type.
 </li><li>Support concurrent opening of databases.
 </li><li>Improved error message and diagnostics in case of network configuration problems.
-</li><li>TRUNCATE should reset the identity columns as in MySQL and MS SQL Server (and possibly other databases).
+</li><li>TRUNCATE should reset the identity columns by default in MySQL and MS SQL Server compatibility modes (and possibly other).
 </li><li>Adding a primary key should make the columns 'not null' unless if there is a row with null
     (compatibility with MySQL, PostgreSQL, HSQLDB; not Derby).
 </li><li>ARRAY data type: support Integer[] and so on in Java functions (currently only Object[] is supported).
@@ -526,7 +520,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
 </li><li>Support [INNER | OUTER] JOIN USING(column [,...]).
 </li><li>Support NATURAL [ { LEFT | RIGHT } [ OUTER ] | INNER ] JOIN (Derby, Oracle)
 </li><li>GROUP BY columnNumber (similar to ORDER BY columnNumber) (MySQL, PostgreSQL, SQLite; not by HSQLDB and Derby).
-</li><li>Sybase / MS SQL Server compatibility: CONVERT(..) parameters are swapped.
 </li><li>Index conditions: WHERE AGE>1 should not scan through all rows with AGE=1.
 </li><li>PHP support: H2 should support PDO, or test with PostgreSQL PDO.
 </li><li>Outer joins: if no column of the outer join table is referenced, the outer join table could be removed from the query.
@@ -539,7 +532,6 @@ See also <a href="build.html#providing_patches">Providing Patches</a>.
     Keep an pointer to the data area and the column id that is already read.
 </li><li>Long running transactions: log session id when detected.
 </li><li>Optimization: "select id from test" should use the index on id even without "order by".
-</li><li>Issue 362: LIMIT support for UPDATE statements (MySQL compatibility).
 </li><li>Sybase SQL Anywhere compatibility: SELECT TOP ... START AT ...
 </li><li>Use Java 6 SQLException subclasses.
 </li><li>Issue 390: RUNSCRIPT FROM '...' CONTINUE_ON_ERROR

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

@@ -148,6 +148,8 @@ import org.h2.engine.UserDataType;
 import org.h2.expression.Aggregate;
 import org.h2.expression.Aggregate.AggregateType;
 import org.h2.expression.Alias;
+import org.h2.expression.BinaryOperation;
+import org.h2.expression.BinaryOperation.OpType;
 import org.h2.expression.CompareLike;
 import org.h2.expression.Comparison;
 import org.h2.expression.ConditionAndOr;
@@ -163,13 +165,12 @@ import org.h2.expression.Function;
 import org.h2.expression.FunctionCall;
 import org.h2.expression.JavaAggregate;
 import org.h2.expression.JavaFunction;
-import org.h2.expression.Operation;
-import org.h2.expression.Operation.OpType;
 import org.h2.expression.Parameter;
 import org.h2.expression.Rownum;
 import org.h2.expression.SequenceValue;
 import org.h2.expression.Subquery;
 import org.h2.expression.TableFunction;
+import org.h2.expression.UnaryOperation;
 import org.h2.expression.ValueExpression;
 import org.h2.expression.Variable;
 import org.h2.expression.Wildcard;
@@ -1797,9 +1798,6 @@ public class Parser {
     }
 
     private IndexHints parseIndexHints(Table table) {
-        if (table == null) {
-            throw getSyntaxError();
-        }
         read(OPEN_PAREN);
         LinkedHashSet<String> indexNames = new LinkedHashSet<>();
         if (!readIf(CLOSE_PAREN)) {
@@ -2858,7 +2856,7 @@ public class Parser {
         Expression r = readSum();
         while (true) {
             if (readIf(STRING_CONCAT)) {
-                r = new Operation(OpType.CONCAT, r, readSum());
+                r = new BinaryOperation(OpType.CONCAT, r, readSum());
             } else if (readIf(TILDE)) {
                 if (readIf(ASTERISK)) {
                     Function function = Function.getFunction(database, "CAST");
@@ -2888,9 +2886,9 @@ public class Parser {
         Expression r = readFactor();
         while (true) {
             if (readIf(PLUS_SIGN)) {
-                r = new Operation(OpType.PLUS, r, readFactor());
+                r = new BinaryOperation(OpType.PLUS, r, readFactor());
             } else if (readIf(MINUS_SIGN)) {
-                r = new Operation(OpType.MINUS, r, readFactor());
+                r = new BinaryOperation(OpType.MINUS, r, readFactor());
             } else {
                 return r;
             }
@@ -2901,11 +2899,11 @@ public class Parser {
         Expression r = readTerm();
         while (true) {
             if (readIf(ASTERISK)) {
-                r = new Operation(OpType.MULTIPLY, r, readTerm());
+                r = new BinaryOperation(OpType.MULTIPLY, r, readTerm());
             } else if (readIf(SLASH)) {
-                r = new Operation(OpType.DIVIDE, r, readTerm());
+                r = new BinaryOperation(OpType.DIVIDE, r, readTerm());
             } else if (readIf(PERCENT)) {
-                r = new Operation(OpType.MODULUS, r, readTerm());
+                r = new BinaryOperation(OpType.MODULUS, r, readTerm());
             } else {
                 return r;
             }
@@ -3551,7 +3549,7 @@ public class Parser {
                 }
                 read();
             } else {
-                r = new Operation(OpType.NEGATE, readTerm(), null);
+                r = new UnaryOperation(readTerm());
             }
             break;
         case PLUS_SIGN:
@@ -3610,7 +3608,7 @@ public class Parser {
             Function function = Function.getFunction(database, "ARRAY_GET");
             function.setParameter(0, r);
             r = readExpression();
-            r = new Operation(OpType.PLUS, r, ValueExpression.get(ValueInt
+            r = new BinaryOperation(OpType.PLUS, r, ValueExpression.get(ValueInt
                     .get(1)));
             function.setParameter(1, r);
             r = function;

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

@@ -12,17 +12,13 @@ import java.util.List;
 import org.h2.api.ErrorCode;
 import org.h2.command.Prepared;
 import org.h2.engine.Database;
-import org.h2.engine.Session;
 import org.h2.engine.Mode.ModeEnum;
+import org.h2.engine.Session;
 import org.h2.expression.Alias;
-import org.h2.expression.Comparison;
-import org.h2.expression.ConditionAndOr;
-import org.h2.expression.ConditionNot;
 import org.h2.expression.Expression;
 import org.h2.expression.ExpressionColumn;
 import org.h2.expression.ExpressionVisitor;
 import org.h2.expression.Function;
-import org.h2.expression.Operation;
 import org.h2.expression.Parameter;
 import org.h2.expression.ValueExpression;
 import org.h2.message.DbException;
@@ -529,6 +525,7 @@ public abstract class Query extends Prepared {
      */
     private static boolean checkOrderOther(Session session, Expression expr, ArrayList<String> expressionSQL) {
         if (expr.isConstant()) {
+            // ValueExpression or other
             return true;
         }
         String exprSQL = expr.getSQL();
@@ -537,38 +534,22 @@ public abstract class Query extends Prepared {
                 return true;
             }
         }
+        int count = expr.getSubexpressionCount();
         if (expr instanceof Function) {
-            Function function = (Function) expr;
-            if (!function.isDeterministic()) {
+            if (!((Function) expr).isDeterministic()) {
                 return false;
             }
-            for (Expression e : function.getArgs()) {
-                if (!checkOrderOther(session, e, expressionSQL)) {
-                    return false;
-                }
-            }
-            return true;
-        }
-        if (expr instanceof Operation) {
-            Operation operation = (Operation) expr;
-            Expression right = operation.getRightSubExpression();
-            return checkOrderOther(session, operation.getLeftSubExpression(), expressionSQL)
-                    && (right == null || checkOrderOther(session, right, expressionSQL));
-        }
-        if (expr instanceof ConditionAndOr) {
-            ConditionAndOr condition = (ConditionAndOr) expr;
-            return checkOrderOther(session, condition.getLeftSubExpression(), expressionSQL)
-                    && checkOrderOther(session, condition.getRightSubExpression(), expressionSQL);
-        }
-        if (expr instanceof ConditionNot) {
-            return checkOrderOther(session, ((ConditionNot) expr).getSubCondition(), expressionSQL);
+        } else if (count <= 0) {
+            // Expression is an ExpressionColumn, Parameter, SequenceValue or
+            // has other unsupported type without subexpressions
+            return false;
         }
-        if (expr instanceof Comparison) {
-            Comparison condition = (Comparison) expr;
-            return checkOrderOther(session, condition.getLeftSubExpression(), expressionSQL)
-                    && checkOrderOther(session, condition.getRightSubExpression(), expressionSQL);
+        for (int i = 0; i < count; i++) {
+            if (!checkOrderOther(session, expr.getSubexpression(i), expressionSQL)) {
+                return false;
+            }
         }
-        return false;
+        return true;
     }
 
     /**

h2/src/main/org/h2/expression/Operation.java → h2/src/main/org/h2/expression/BinaryOperation.java

@@ -21,7 +21,7 @@ import org.h2.value.ValueString;
 /**
  * A mathematical expression, or string concatenation.
  */
-public class Operation extends Expression {
+public class BinaryOperation extends Expression {
 
     public enum OpType {
         /**
@@ -50,11 +50,6 @@ public class Operation extends Expression {
          */
         DIVIDE,
 
-        /**
-         * This operation represents a negation as in - ID.
-         */
-        NEGATE,
-
         /**
          * This operation represents a modulus as in 5 % 2.
          */
@@ -66,7 +61,7 @@ public class Operation extends Expression {
     private int dataType;
     private boolean convertRight = true;
 
-    public Operation(OpType opType, Expression left, Expression right) {
+    public BinaryOperation(OpType opType, Expression left, Expression right) {
         this.opType = opType;
         this.left = left;
         this.right = right;
@@ -74,23 +69,13 @@ public class Operation extends Expression {
 
     @Override
     public String getSQL() {
-        String sql;
-        if (opType == OpType.NEGATE) {
-            // don't remove the space, otherwise it might end up some thing like
-            // --1 which is a line remark
-            sql = "- " + left.getSQL();
-        } else {
-            // don't remove the space, otherwise it might end up some thing like
-            // --1 which is a line remark
-            sql = left.getSQL() + " " + getOperationToken() + " " + right.getSQL();
-        }
-        return "(" + sql + ")";
+        // don't remove the space, otherwise it might end up some thing like
+        // --1 which is a line remark
+        return '(' + left.getSQL() + ' ' + getOperationToken() + ' ' + right.getSQL() + ')';
     }
 
     private String getOperationToken() {
         switch (opType) {
-        case NEGATE:
-            return "-";
         case CONCAT:
             return "||";
         case PLUS:
@@ -112,18 +97,11 @@ public class Operation extends Expression {
     public Value getValue(Session session) {
         Mode mode = session.getDatabase().getMode();
         Value l = left.getValue(session).convertTo(dataType, mode);
-        Value r;
-        if (right == null) {
-            r = null;
-        } else {
-            r = right.getValue(session);
-            if (convertRight) {
-                r = r.convertTo(dataType, mode);
-            }
+        Value r = right.getValue(session);
+        if (convertRight) {
+            r = r.convertTo(dataType, mode);
         }
         switch (opType) {
-        case NEGATE:
-            return l == ValueNull.INSTANCE ? l : l.negate();
         case CONCAT: {
             if (l == ValueNull.INSTANCE) {
                 if (mode.nullConcatIsNull) {
@@ -174,36 +152,22 @@ public class Operation extends Expression {
     @Override
     public void mapColumns(ColumnResolver resolver, int level) {
         left.mapColumns(resolver, level);
-        if (right != null) {
-            right.mapColumns(resolver, level);
-        }
+        right.mapColumns(resolver, level);
     }
 
     @Override
     public Expression optimize(Session session) {
         left = left.optimize(session);
+        right = right.optimize(session);
         switch (opType) {
-        case NEGATE:
-            dataType = left.getType();
-            if (dataType == Value.UNKNOWN) {
-                dataType = Value.DECIMAL;
-            } else if (dataType == Value.ENUM) {
-                dataType = Value.INT;
-            }
-            break;
         case CONCAT:
-            right = right.optimize(session);
             dataType = Value.STRING;
-            if (left.isConstant() && right.isConstant()) {
-                return ValueExpression.get(getValue(session));
-            }
             break;
         case PLUS:
         case MINUS:
         case MULTIPLY:
         case DIVIDE:
         case MODULUS:
-            right = right.optimize(session);
             int l = left.getType();
             int r = right.getType();
             if ((l == Value.NULL && r == Value.NULL) ||
@@ -234,7 +198,7 @@ public class Operation extends Expression {
         default:
             DbException.throwInternalError("type=" + opType);
         }
-        if (left.isConstant() && (right == null || right.isConstant())) {
+        if (left.isConstant() && right.isConstant()) {
             return ValueExpression.get(getValue(session));
         }
         return this;
@@ -334,7 +298,7 @@ public class Operation extends Expression {
                 // Oracle date add
                 Function f = Function.getFunction(session.getDatabase(), "DATEADD");
                 f.setParameter(0, ValueExpression.get(ValueString.get("SECOND")));
-                left = new Operation(OpType.MULTIPLY, ValueExpression.get(ValueInt
+                left = new BinaryOperation(OpType.MULTIPLY, ValueExpression.get(ValueInt
                         .get(60 * 60 * 24)), left);
                 f.setParameter(1, left);
                 f.setParameter(2, right);
@@ -361,7 +325,7 @@ public class Operation extends Expression {
                     // Oracle date subtract
                     Function f = Function.getFunction(session.getDatabase(), "DATEADD");
                     f.setParameter(0, ValueExpression.get(ValueString.get("DAY")));
-                    right = new Operation(OpType.NEGATE, right, null);
+                    right = new UnaryOperation(right);
                     right = right.optimize(session);
                     f.setParameter(1, right);
                     f.setParameter(2, left);
@@ -374,9 +338,9 @@ public class Operation extends Expression {
                     // Oracle date subtract
                     Function f = Function.getFunction(session.getDatabase(), "DATEADD");
                     f.setParameter(0, ValueExpression.get(ValueString.get("SECOND")));
-                    right = new Operation(OpType.MULTIPLY, ValueExpression.get(ValueInt
+                    right = new BinaryOperation(OpType.MULTIPLY, ValueExpression.get(ValueInt
                             .get(60 * 60 * 24)), right);
-                    right = new Operation(OpType.NEGATE, right, null);
+                    right = new UnaryOperation(right);
                     right = right.optimize(session);
                     f.setParameter(1, right);
                     f.setParameter(2, left);
@@ -437,9 +401,7 @@ public class Operation extends Expression {
     @Override
     public void setEvaluatable(TableFilter tableFilter, boolean b) {
         left.setEvaluatable(tableFilter, b);
-        if (right != null) {
-            right.setEvaluatable(tableFilter, b);
-        }
+        right.setEvaluatable(tableFilter, b);
     }
 
     @Override
@@ -449,74 +411,61 @@ public class Operation extends Expression {
 
     @Override
     public long getPrecision() {
-        if (right != null) {
-            switch (opType) {
-            case CONCAT:
-                return left.getPrecision() + right.getPrecision();
-            default:
-                return Math.max(left.getPrecision(), right.getPrecision());
-            }
+        switch (opType) {
+        case CONCAT:
+            return left.getPrecision() + right.getPrecision();
+        default:
+            return Math.max(left.getPrecision(), right.getPrecision());
         }
-        return left.getPrecision();
     }
 
     @Override
     public int getDisplaySize() {
-        if (right != null) {
-            switch (opType) {
-            case CONCAT:
-                return MathUtils.convertLongToInt((long) left.getDisplaySize() +
-                        (long) right.getDisplaySize());
-            default:
-                return Math.max(left.getDisplaySize(), right.getDisplaySize());
-            }
+        switch (opType) {
+        case CONCAT:
+            return MathUtils.convertLongToInt((long) left.getDisplaySize() +
+                    (long) right.getDisplaySize());
+        default:
+            return Math.max(left.getDisplaySize(), right.getDisplaySize());
         }
-        return left.getDisplaySize();
     }
 
     @Override
     public int getScale() {
-        if (right != null) {
-            return Math.max(left.getScale(), right.getScale());
-        }
-        return left.getScale();
+        return Math.max(left.getScale(), right.getScale());
     }
 
     @Override
     public void updateAggregate(Session session) {
         left.updateAggregate(session);
-        if (right != null) {
-            right.updateAggregate(session);
-        }
+        right.updateAggregate(session);
     }
 
     @Override
     public boolean isEverything(ExpressionVisitor visitor) {
-        return left.isEverything(visitor) &&
-                (right == null || right.isEverything(visitor));
+        return left.isEverything(visitor) && right.isEverything(visitor);
     }
 
     @Override
     public int getCost() {
-        return left.getCost() + 1 + (right == null ? 0 : right.getCost());
+        return left.getCost() + right.getCost() + 1;
     }
 
-    /**
-     * Get the left sub-expression of this operation.
-     *
-     * @return the left sub-expression
-     */
-    public Expression getLeftSubExpression() {
-        return left;
+    @Override
+    public int getSubexpressionCount() {
+        return 2;
     }
 
-    /**
-     * Get the right sub-expression of this operation.
-     *
-     * @return the right sub-expression
-     */
-    public Expression getRightSubExpression() {
-        return right;
+    @Override
+    public Expression getSubexpression(int index) {
+        switch (index) {
+        case 0:
+            return left;
+        case 1:
+            return right;
+        default:
+            throw new IndexOutOfBoundsException();
+        }
     }
 
 }

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

@@ -587,22 +587,24 @@ public class Comparison extends Condition {
         return null;
     }
 
-    /**
-     * Get the left sub-expression of this condition.
-     *
-     * @return the left sub-expression
-     */
-    public Expression getLeftSubExpression() {
-        return left;
+    @Override
+    public int getSubexpressionCount() {
+        return compareType == IS_NULL || compareType == IS_NOT_NULL ? 1 : 2;
     }
 
-    /**
-     * Get the right sub-expression of this condition.
-     *
-     * @return the right sub-expression
-     */
-    public Expression getRightSubExpression() {
-        return right;
+    @Override
+    public Expression getSubexpression(int index) {
+        switch (index) {
+        case 0:
+            return left;
+        case 1:
+            if (compareType != IS_NULL && compareType != IS_NOT_NULL) {
+                return right;
+            }
+            //$FALL-THROUGH$
+        default:
+            throw new IndexOutOfBoundsException();
+        }
     }
 
 }

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

@@ -283,22 +283,21 @@ public class ConditionAndOr extends Condition {
         return left.getCost() + right.getCost();
     }
 
-    /**
-     * Get the left sub-expression of this condition.
-     *
-     * @return the left sub-expression
-     */
-    public Expression getLeftSubExpression() {
-        return left;
+    @Override
+    public int getSubexpressionCount() {
+        return 2;
     }
 
-    /**
-     * Get the right sub-expression of this condition.
-     *
-     * @return the right sub-expression
-     */
-    public Expression getRightSubExpression() {
-        return right;
+    @Override
+    public Expression getSubexpression(int index) {
+        switch (index) {
+        case 0:
+            return left;
+        case 1:
+            return right;
+        default:
+            throw new IndexOutOfBoundsException();
+        }
     }
 
 }

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

@@ -98,13 +98,17 @@ public class ConditionNot extends Condition {
         return condition.getCost();
     }
 
-    /**
-     * Get the sub-expression of this condition.
-     *
-     * @return the sub-expression
-     */
-    public Expression getSubCondition() {
-        return condition;
+    @Override
+    public int getSubexpressionCount() {
+        return 1;
+    }
+
+    @Override
+    public Expression getSubexpression(int index) {
+        if (index == 0) {
+            return condition;
+        }
+        throw new IndexOutOfBoundsException();
     }
 
 }

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

@@ -357,4 +357,24 @@ public abstract class Expression {
         }
     }
 
+    /**
+     * Returns count of subexpressions.
+     *
+     * @return count of subexpressions
+     */
+    public int getSubexpressionCount() {
+        return 0;
+    }
+
+    /**
+     * Returns subexpression with specified index.
+     *
+     * @param index 0-based index
+     * @return subexpression with specified index
+     * @throws IndexOutOfBoundsException if specified index is not valid
+     */
+    public Expression getSubexpression(int index) {
+        throw new IndexOutOfBoundsException();
+    }
+
 }

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

@@ -2710,4 +2710,14 @@ public class Function extends Expression implements FunctionCall {
         return info.type == NEXTVAL;
     }
 
+    @Override
+    public int getSubexpressionCount() {
+        return args.length;
+    }
+
+    @Override
+    public Expression getSubexpression(int index) {
+        return args[index];
+    }
+
 }

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

+/*
+ * Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
+ * and the EPL 1.0 (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.expression;
+
+import org.h2.engine.Session;
+import org.h2.table.ColumnResolver;
+import org.h2.table.TableFilter;
+import org.h2.value.Value;
+import org.h2.value.ValueNull;
+
+/**
+ * Unary operation. Only negation operation is currently supported.
+ */
+public class UnaryOperation extends Expression {
+
+    private Expression arg;
+    private int dataType;
+
+    public UnaryOperation(Expression arg) {
+        this.arg = arg;
+    }
+
+    @Override
+    public String getSQL() {
+        // don't remove the space, otherwise it might end up some thing like
+        // --1 which is a line remark
+        return "(- " + arg.getSQL() + ')';
+    }
+
+    @Override
+    public Value getValue(Session session) {
+        Value a = arg.getValue(session).convertTo(dataType, session.getDatabase().getMode());
+        return a == ValueNull.INSTANCE ? a : a.negate();
+    }
+
+    @Override
+    public void mapColumns(ColumnResolver resolver, int level) {
+        arg.mapColumns(resolver, level);
+    }
+
+    @Override
+    public Expression optimize(Session session) {
+        arg = arg.optimize(session);
+        dataType = arg.getType();
+        if (dataType == Value.UNKNOWN) {
+            dataType = Value.DECIMAL;
+        } else if (dataType == Value.ENUM) {
+            dataType = Value.INT;
+        }
+        if (arg.isConstant()) {
+            return ValueExpression.get(getValue(session));
+        }
+        return this;
+    }
+
+    @Override
+    public void setEvaluatable(TableFilter tableFilter, boolean b) {
+        arg.setEvaluatable(tableFilter, b);
+    }
+
+    @Override
+    public int getType() {
+        return dataType;
+    }
+
+    @Override
+    public long getPrecision() {
+        return arg.getPrecision();
+    }
+
+    @Override
+    public int getDisplaySize() {
+        return arg.getDisplaySize();
+    }
+
+    @Override
+    public int getScale() {
+        return arg.getScale();
+    }
+
+    @Override
+    public void updateAggregate(Session session) {
+        arg.updateAggregate(session);
+    }
+
+    @Override
+    public boolean isEverything(ExpressionVisitor visitor) {
+        return arg.isEverything(visitor);
+    }
+
+    @Override
+    public int getCost() {
+        return arg.getCost() + 1;
+    }
+
+    @Override
+    public int getSubexpressionCount() {
+        return 1;
+    }
+
+    @Override
+    public Expression getSubexpression(int index) {
+        if (index == 0) {
+            return arg;
+        }
+        throw new IndexOutOfBoundsException();
+    }
+
+}

h2/src/main/org/h2/fulltext/FullText.java

@@ -669,19 +669,17 @@ public class FullText {
             ArrayList<String> data, Expression expr) {
         if (expr instanceof ConditionAndOr) {
             ConditionAndOr and = (ConditionAndOr) expr;
-            Expression left = and.getLeftSubExpression();
-            Expression right = and.getRightSubExpression();
-            addColumnData(columns, data, left);
-            addColumnData(columns, data, right);
+            addColumnData(columns, data, and.getSubexpression(0));
+            addColumnData(columns, data, and.getSubexpression(1));
         } else {
             Comparison comp = (Comparison) expr;
-            ExpressionColumn ec = (ExpressionColumn) comp.getLeftSubExpression();
-            ValueExpression ev = (ValueExpression) comp.getRightSubExpression();
+            ExpressionColumn ec = (ExpressionColumn) comp.getSubexpression(0);
             String columnName = ec.getColumnName();
             columns.add(columnName);
-            if (ev == null) {
+            if (expr.getSubexpressionCount() == 1) {
                 data.add(null);
             } else {
+                ValueExpression ev = (ValueExpression) comp.getSubexpression(1);
                 data.add(ev.getValue(null).getString());
             }
         }

h2/src/test/org/h2/test/scripts/distinct.sql

@@ -66,6 +66,9 @@ SELECT DISTINCT NAME, ID + 1 FROM TEST ORDER BY UPPER(NAME) || (ID + 1);
 SELECT DISTINCT ID FROM TEST ORDER BY NAME;
 > exception ORDER_BY_NOT_IN_RESULT
 
+SELECT DISTINCT ID FROM TEST ORDER BY UPPER(NAME);
+> exception ORDER_BY_NOT_IN_RESULT
+
 SELECT DISTINCT ID FROM TEST ORDER BY CURRENT_TIMESTAMP;
 > exception ORDER_BY_NOT_IN_RESULT
 

h2/src/tools/org/h2/build/doc/dictionary.txt

@@ -789,4 +789,4 @@ inconsistencies discover eliminated violates tweaks postpone leftovers
 tied ties
 launched unavailable smallmoney erroneously multiplier newid pan streamline unmap preview unexpectedly presumably
 converging smth rng curs casts unmapping unmapper
-immediate hhmmss scheduled hhmm prematurely postponed arranges
+immediate hhmmss scheduled hhmm prematurely postponed arranges subexpression subexpressions