Add Expression.getSQL(StringBuilder)

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

@@ -422,7 +422,7 @@ public abstract class Prepared {
         for (Expression e : list) {
             buff.appendExceptFirst(", ");
             if (e != null) {
-                buff.append(e.getSQL());
+                e.getSQL(buff.builder());
             }
         }
         return buff.toString();

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

@@ -421,7 +421,8 @@ public class Insert extends Prepared implements ResultTarget {
         for (Column column : duplicateKeyAssignmentMap.keySet()) {
             buff.appendExceptFirst(", ");
             Expression ex = duplicateKeyAssignmentMap.get(column);
-            buff.append(column.getSQL()).append('=').append(ex.getSQL());
+            buff.append(column.getSQL()).append('=');
+            ex.getSQL(buff.builder());
         }
         buff.append(" WHERE ");
         Index foundIndex = (Index) de.getSource();
@@ -429,7 +430,7 @@ public class Insert extends Prepared implements ResultTarget {
             throw DbException.getUnsupportedException(
                     "Unable to apply ON DUPLICATE KEY UPDATE, no index found!");
         }
-        buff.append(prepareUpdateCondition(foundIndex, row).getSQL());
+        prepareUpdateCondition(foundIndex, row).getSQL(buff.builder());
         String sql = buff.toString();
         Update command = (Update) session.prepare(sql);
         command.setUpdateToCurrentValuesReturnsZero(true);

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

@@ -248,7 +248,7 @@ public class Merge extends Prepared {
                     if (e == null) {
                         buff.append("DEFAULT");
                     } else {
-                        buff.append(e.getSQL());
+                        e.getSQL(buff.builder());
                     }
                 }
                 buff.append(')');

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

@@ -228,7 +228,7 @@ public class Replace extends Prepared {
                     if (e == null) {
                         buff.append("DEFAULT");
                     } else {
-                        buff.append(e.getSQL());
+                        e.getSQL(buff.builder());
                     }
                 }
                 buff.append(')');

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

@@ -1327,7 +1327,7 @@ public class Select extends Query {
                 buff.append(" ON(");
                 for (Expression distinctExpression: distinctExpressions) {
                     buff.appendExceptFirst(", ");
-                    buff.append(distinctExpression.getSQL());
+                    distinctExpression.getSQL(buff.builder());
                 }
                 buff.append(')');
                 buff.resetCount();

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

@@ -33,9 +33,10 @@ public class SelectOrderBy {
     public String getSQL() {
         StringBuilder buff = new StringBuilder();
         if (expression != null) {
-            buff.append('=').append(expression.getSQL());
+            buff.append('=');
+            expression.getSQL(buff);
         } else {
-            buff.append(columnIndexExpr.getSQL());
+            columnIndexExpr.getSQL(buff);
         }
         SortOrder.typeToString(buff, sortType);
         return buff.toString();

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

@@ -222,7 +222,8 @@ public class Update extends Prepared {
         for (Column c : columns) {
             Expression e = expressionMap.get(c);
             buff.appendExceptFirst(",\n    ");
-            buff.append(c.getName()).append(" = ").append(e.getSQL());
+            buff.append(c.getName()).append(" = ");
+            e.getSQL(buff.builder());
         }
         if (condition != null) {
             buff.append("\nWHERE ").append(StringUtils.unEnclose(condition.getSQL()));

h2/src/main/org/h2/constraint/ConstraintCheck.java

@@ -64,7 +64,9 @@ public class ConstraintCheck extends Constraint {
     }
 
     private String getShortDescription() {
-        return getName() + ": " + expr.getSQL();
+        StringBuilder builder = new StringBuilder().append(getName()).append(": ");
+        expr.getSQL(builder);
+        return builder.toString();
     }
 
     @Override
@@ -140,8 +142,11 @@ public class ConstraintCheck extends Constraint {
             // don't check at startup
             return;
         }
-        String sql = "SELECT 1 FROM " + filter.getTable().getSQL() +
-                " WHERE NOT(" + expr.getSQL() + ")";
+        StringBuilder builder = new StringBuilder().append("SELECT 1 FROM ")
+                .append(filter.getTable().getSQL())
+                .append(" WHERE NOT(");
+        expr.getSQL(builder).append(')');
+        String sql = builder.toString();
         ResultInterface r = session.prepare(sql).query(1);
         if (r.next()) {
             throw DbException.get(ErrorCode.CHECK_CONSTRAINT_VIOLATED_1, getName());

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

@@ -78,8 +78,8 @@ public class Alias extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        return expr.getSQL() + " AS " + Parser.quoteIdentifier(alias);
+    public StringBuilder getSQL(StringBuilder builder) {
+        return expr.getSQL(builder).append(" AS ").append(Parser.quoteIdentifier(alias));
     }
 
     @Override

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

@@ -68,10 +68,12 @@ public class BinaryOperation extends Expression {
     }
 
     @Override
-    public String getSQL() {
+    public StringBuilder getSQL(StringBuilder builder) {
         // 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() + ')';
+        builder.append('(');
+        left.getSQL(builder).append(' ').append(getOperationToken()).append(' ');
+        return right.getSQL(builder).append(')');
     }
 
     private String getOperationToken() {

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

@@ -76,17 +76,20 @@ public class CompareLike extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        String sql;
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
         if (regexp) {
-            sql = left.getSQL() + " REGEXP " + right.getSQL();
+            left.getSQL(builder).append(" REGEXP ");
+            right.getSQL(builder);
         } else {
-            sql = left.getSQL() + " LIKE " + right.getSQL();
+            left.getSQL(builder).append(" LIKE ");
+            right.getSQL(builder);
             if (escape != null) {
-                sql += " ESCAPE " + escape.getSQL();
+                builder.append(" ESCAPE ");
+                escape.getSQL(builder);
             }
         }
-        return "(" + sql + ")";
+        return builder.append(')');
     }
 
     @Override

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

@@ -126,23 +126,25 @@ public class Comparison extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        String sql;
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
         switch (compareType) {
         case IS_NULL:
-            sql = left.getSQL() + " IS NULL";
+            left.getSQL(builder).append(" IS NULL");
             break;
         case IS_NOT_NULL:
-            sql = left.getSQL() + " IS NOT NULL";
+            left.getSQL(builder).append(" IS NOT NULL");
             break;
         case SPATIAL_INTERSECTS:
-            sql = "INTERSECTS(" + left.getSQL() + ", " + right.getSQL() + ")";
+            builder.append("INTERSECTS(");
+            left.getSQL(builder).append(", ");
+            right.getSQL(builder).append(')');
             break;
         default:
-            sql = left.getSQL() + " " + getCompareOperator(compareType) +
-                    " " + right.getSQL();
+            left.getSQL(builder).append(' ').append(getCompareOperator(compareType)).append(' ');
+            right.getSQL(builder);
         }
-        return "(" + sql + ")";
+        return builder.append(')');
     }
 
     /**

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

@@ -42,19 +42,20 @@ public class ConditionAndOr extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        String sql;
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder);
         switch (andOrType) {
         case AND:
-            sql = left.getSQL() + "\n    AND " + right.getSQL();
+            builder.append("\n    AND ");
             break;
         case OR:
-            sql = left.getSQL() + "\n    OR " + right.getSQL();
+            builder.append("\n    OR ");
             break;
         default:
             throw DbException.throwInternalError("andOrType=" + andOrType);
         }
-        return "(" + sql + ")";
+        return right.getSQL(builder).append(')');
     }
 
     @Override

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

@@ -41,8 +41,10 @@ public class ConditionExists extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        return "EXISTS(\n" + StringUtils.indent(query.getPlanSQL(), 4, false) + ")";
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append("EXISTS(\n");
+        builder.append(StringUtils.indent(query.getPlanSQL(), 4, false));
+        return builder.append(')');
     }
 
     @Override

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

@@ -11,7 +11,6 @@ import org.h2.engine.Session;
 import org.h2.index.IndexCondition;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.Value;
 import org.h2.value.ValueBoolean;
 import org.h2.value.ValueNull;
@@ -152,14 +151,16 @@ public class ConditionIn extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder("(");
-        buff.append(left.getSQL()).append(" IN(");
-        for (Expression e : valueList) {
-            buff.appendExceptFirst(", ");
-            buff.append(e.getSQL());
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder).append(" IN(");
+        for (int i = 0; i < valueList.size(); i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            valueList.get(i).getSQL(builder);
         }
-        return buff.append("))").toString();
+        return builder.append("))");
     }
 
     @Override

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

@@ -15,7 +15,6 @@ import org.h2.index.IndexCondition;
 import org.h2.message.DbException;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.ExtTypeInfo;
 import org.h2.value.Value;
 import org.h2.value.ValueBoolean;
@@ -114,14 +113,16 @@ public class ConditionInConstantSet extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder("(");
-        buff.append(left.getSQL()).append(" IN(");
-        for (Expression e : valueList) {
-            buff.appendExceptFirst(", ");
-            buff.append(e.getSQL());
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder).append(" IN(");
+        for (int i = 0, s = valueList.size(); i < s; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            valueList.get(i).getSQL(builder);
         }
-        return buff.append("))").toString();
+        return builder.append("))");
     }
 
     @Override

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

@@ -140,8 +140,10 @@ public class ConditionInParameter extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        return '(' + left.getSQL() + " = ANY(" + parameter.getSQL() + "))";
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder).append(" = ANY(");
+        return parameter.getSQL(builder).append("))");
     }
 
     @Override

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

@@ -129,23 +129,21 @@ public class ConditionInSelect extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        StringBuilder buff = new StringBuilder();
-        buff.append('(').append(left.getSQL()).append(' ');
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder).append(' ');
         if (all) {
-            buff.append(Comparison.getCompareOperator(compareType)).
+            builder.append(Comparison.getCompareOperator(compareType)).
                 append(" ALL");
         } else {
             if (compareType == Comparison.EQUAL) {
-                buff.append("IN");
+                builder.append("IN");
             } else {
-                buff.append(Comparison.getCompareOperator(compareType)).
+                builder.append(Comparison.getCompareOperator(compareType)).
                     append(" ANY");
             }
         }
-        buff.append("(\n").append(StringUtils.indent(query.getPlanSQL(), 4, false)).
-            append("))");
-        return buff.toString();
+        return builder.append("(\n").append(StringUtils.indent(query.getPlanSQL(), 4, false)).append("))");
     }
 
     @Override

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

@@ -65,8 +65,9 @@ public class ConditionNot extends Condition {
     }
 
     @Override
-    public String getSQL() {
-        return "(NOT " + condition.getSQL() + ")";
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append("(NOT ");
+        return condition.getSQL(builder).append(')');
     }
 
     @Override

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

@@ -110,7 +110,22 @@ public abstract class Expression {
      *
      * @return the SQL statement
      */
-    public abstract String getSQL();
+    public String getSQL() {
+        StringBuilder builder = new StringBuilder();
+        getSQL(builder);
+        return builder.toString();
+    }
+
+    /**
+     * Appends the SQL statement of this expression to the specified builder.
+     * This may not always be the original SQL statement, specially after
+     * optimization.
+     *
+     * @param builder
+     *            string builder
+     * @return the specified string builder
+     */
+    public abstract StringBuilder getSQL(StringBuilder builder);
 
     /**
      * Update an aggregate value. This method is called at statement execution

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

@@ -55,23 +55,22 @@ public class ExpressionColumn extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        String sql;
+    public StringBuilder getSQL(StringBuilder builder) {
         boolean quote = database.getSettings().databaseToUpper;
-        if (column != null) {
-            sql = column.getSQL();
-        } else {
-            sql = quote ? Parser.quoteIdentifier(columnName) : columnName;
+        if (schemaName != null) {
+            String s = quote ? Parser.quoteIdentifier(schemaName) : schemaName;
+            builder.append(s).append('.');
         }
         if (tableAlias != null) {
             String a = quote ? Parser.quoteIdentifier(tableAlias) : tableAlias;
-            sql = a + "." + sql;
+            builder.append(a).append('.');
         }
-        if (schemaName != null) {
-            String s = quote ? Parser.quoteIdentifier(schemaName) : schemaName;
-            sql = s + "." + sql;
+        if (column != null) {
+            builder.append(column.getSQL());
+        } else {
+            builder.append(quote ? Parser.quoteIdentifier(columnName) : columnName);
         }
-        return sql;
+        return builder;
     }
 
     public TableFilter getTableFilter() {

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

@@ -9,7 +9,6 @@ import org.h2.engine.Session;
 import org.h2.table.Column;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
 
@@ -85,16 +84,18 @@ public class ExpressionList extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder("(");
-        for (Expression e: list) {
-            buff.appendExceptFirst(", ");
-            buff.append(e.getSQL());
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        for (int i = 0; i < list.length; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            list[i].getSQL(builder);
         }
         if (list.length == 1) {
-            buff.append(',');
+            builder.append(',');
         }
-        return buff.append(')').toString();
+        return builder.append(')');
     }
 
     @Override

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

@@ -50,7 +50,6 @@ import org.h2.util.DateTimeUtils;
 import org.h2.util.IOUtils;
 import org.h2.util.JdbcUtils;
 import org.h2.util.MathUtils;
-import org.h2.util.StatementBuilder;
 import org.h2.util.StringUtils;
 import org.h2.util.ToChar;
 import org.h2.util.ToDateParser;
@@ -2582,36 +2581,41 @@ public class Function extends Expression implements FunctionCall {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder(info.name);
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append(info.name);
         if (info.type == CASE) {
             if (args[0] != null) {
-                buff.append(' ').append(args[0].getSQL());
+                builder.append(' ');
+                args[0].getSQL(builder);
             }
             for (int i = 1, len = args.length - 1; i < len; i += 2) {
-                buff.append(" WHEN ").append(args[i].getSQL());
-                buff.append(" THEN ").append(args[i + 1].getSQL());
+                builder.append(" WHEN ");
+                args[i].getSQL(builder);
+                builder.append(" THEN ");
+                args[i + 1].getSQL(builder);
             }
             if (args.length % 2 == 0) {
-                buff.append(" ELSE ").append(args[args.length - 1].getSQL());
+                builder.append(" ELSE ");
+                args[args.length - 1].getSQL(builder);
             }
-            return buff.append(" END").toString();
+            return builder.append(" END");
         }
-        buff.append('(');
+        builder.append('(');
         switch (info.type) {
         case CAST: {
-            buff.append(args[0].getSQL()).append(" AS ").
+            args[0].getSQL(builder).append(" AS ").
                 append(new Column(null, dataType, precision,
                         scale, displaySize, extTypeInfo).getCreateSQL());
             break;
         }
         case CONVERT: {
             if (database.getMode().swapConvertFunctionParameters) {
-                buff.append(new Column(null, dataType, precision,
+                builder.append(new Column(null, dataType, precision,
                         scale, displaySize).getCreateSQL()).
-                    append(',').append(args[0].getSQL());
+                    append(',');
+                args[0].getSQL(builder);
             } else {
-                buff.append(args[0].getSQL()).append(',').
+                args[0].getSQL(builder).append(',').
                     append(new Column(null, dataType, precision,
                         scale, displaySize).getCreateSQL());
             }
@@ -2619,17 +2623,20 @@ public class Function extends Expression implements FunctionCall {
         }
         case EXTRACT: {
             ValueString v = (ValueString) ((ValueExpression) args[0]).getValue(null);
-            buff.append(v.getString()).append(" FROM ").append(args[1].getSQL());
+            builder.append(v.getString()).append(" FROM ");
+            args[1].getSQL(builder);
             break;
         }
         default: {
-            for (Expression e : args) {
-                buff.appendExceptFirst(", ");
-                buff.append(e.getSQL());
+            for (int i = 0; i < args.length; i++) {
+                if (i > 0) {
+                    builder.append(", ");
+                }
+                args[i].getSQL(builder);
             }
         }
         }
-        return buff.append(')').toString();
+        return builder.append(')');
     }
 
     @Override

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

@@ -113,8 +113,10 @@ public class IntervalOperation extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        return '(' + left.getSQL() + ' ' + getOperationToken() + ' ' + right.getSQL() + ')';
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append('(');
+        left.getSQL(builder).append(' ').append(getOperationToken()).append(' ');
+        return right.getSQL(builder).append(')');
     }
 
     private char getOperationToken() {

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

@@ -11,7 +11,6 @@ import org.h2.engine.FunctionAlias;
 import org.h2.engine.Session;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.DataType;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
@@ -89,21 +88,22 @@ public class JavaFunction extends Expression implements FunctionCall {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder();
+    public StringBuilder getSQL(StringBuilder builder) {
         // TODO always append the schema once FUNCTIONS_IN_SCHEMA is enabled
         if (functionAlias.getDatabase().getSettings().functionsInSchema ||
                 !functionAlias.getSchema().getName().equals(Constants.SCHEMA_MAIN)) {
-            buff.append(
+            builder.append(
                     Parser.quoteIdentifier(functionAlias.getSchema().getName()))
                     .append('.');
         }
-        buff.append(Parser.quoteIdentifier(functionAlias.getName())).append('(');
-        for (Expression e : args) {
-            buff.appendExceptFirst(", ");
-            buff.append(e.getSQL());
+        builder.append(Parser.quoteIdentifier(functionAlias.getName())).append('(');
+        for (int i = 0; i < args.length; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            args[i].getSQL(builder);
         }
-        return buff.append(')').toString();
+        return builder.append(')');
     }
 
     @Override

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

@@ -30,8 +30,8 @@ public class Parameter extends Expression implements ParameterInterface {
     }
 
     @Override
-    public String getSQL() {
-        return "?" + (index + 1);
+    public StringBuilder getSQL(StringBuilder builder) {
+        return builder.append('?').append(index + 1);
     }
 
     @Override

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

@@ -72,6 +72,11 @@ public class Rownum extends Expression {
         return "ROWNUM()";
     }
 
+    @Override
+    public StringBuilder getSQL(StringBuilder builder) {
+        return builder.append("ROWNUM()");
+    }
+
     @Override
     public void updateAggregate(Session session, int stage) {
         // nothing to do

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

@@ -67,8 +67,9 @@ public class SequenceValue extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        return "(NEXT VALUE FOR " + sequence.getSQL() +")";
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append("(NEXT VALUE FOR ");
+        return builder.append(sequence.getSQL()).append(')');
     }
 
     @Override

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

@@ -89,8 +89,8 @@ public class Subquery extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        return "(" + query.getPlanSQL() + ")";
+    public StringBuilder getSQL(StringBuilder builder) {
+        return builder.append('(').append(query.getPlanSQL()).append(')');
     }
 
     @Override

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

@@ -52,7 +52,8 @@ public class TableFunction extends Function {
         int i = 0;
         for (Expression e : args) {
             buff.appendExceptFirst(", ");
-            buff.append(columnList[i++].getCreateSQL()).append('=').append(e.getSQL());
+            buff.append(columnList[i++].getCreateSQL()).append('=');
+            e.getSQL(buff.builder());
         }
         return buff.append(')').toString();
     }

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

@@ -24,10 +24,11 @@ public class UnaryOperation extends Expression {
     }
 
     @Override
-    public String getSQL() {
+    public StringBuilder getSQL(StringBuilder builder) {
         // don't remove the space, otherwise it might end up some thing like
         // --1 which is a line remark
-        return "(- " + arg.getSQL() + ')';
+        builder.append("(- ");
+        return arg.getSQL(builder).append(')');
     }
 
     @Override

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

@@ -142,6 +142,16 @@ public class ValueExpression extends Expression {
         return value.getSQL();
     }
 
+    @Override
+    public StringBuilder getSQL(StringBuilder builder) {
+        if (this == DEFAULT) {
+            builder.append("DEFAULT");
+        } else {
+            builder.append(value.getSQL());
+        }
+        return builder;
+    }
+
     @Override
     public void updateAggregate(Session session, int stage) {
         // nothing to do

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

@@ -41,8 +41,8 @@ public class Variable extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        return "@" + Parser.quoteIdentifier(name);
+    public StringBuilder getSQL(StringBuilder builder) {
+        return builder.append('@').append(Parser.quoteIdentifier(name));
     }
 
     @Override

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

@@ -116,8 +116,7 @@ public class Wildcard extends Expression {
     }
 
     @Override
-    public String getSQL() {
-        StringBuilder builder = new StringBuilder();
+    public StringBuilder getSQL(StringBuilder builder) {
         if (table != null) {
             builder.append(StringUtils.quoteIdentifier(table)).append('.');
         }
@@ -128,12 +127,11 @@ public class Wildcard extends Expression {
                 if (i > 0) {
                     builder.append(", ");
                 }
-                ExpressionColumn ec = exceptColumns.get(i);
-                builder.append(ec.getSQL());
+                exceptColumns.get(i).getSQL(builder);
             }
             builder.append(')');
         }
-        return builder.toString();
+        return builder;
     }
 
     @Override

h2/src/main/org/h2/expression/aggregate/AbstractAggregate.java

@@ -159,7 +159,8 @@ public abstract class AbstractAggregate extends DataAnalysisOperation {
     @Override
     protected StringBuilder appendTailConditions(StringBuilder builder) {
         if (filterCondition != null) {
-            builder.append(" FILTER (WHERE ").append(filterCondition.getSQL()).append(')');
+            builder.append(" FILTER (WHERE ");
+            filterCondition.getSQL(builder).append(')');
         }
         return super.appendTailConditions(builder);
     }

h2/src/main/org/h2/expression/aggregate/Aggregate.java

@@ -729,39 +729,40 @@ public class Aggregate extends AbstractAggregate {
         return displaySize;
     }
 
-    private String getSQLGroupConcat() {
-        StringBuilder buff = new StringBuilder("GROUP_CONCAT(");
+    private StringBuilder getSQLGroupConcat(StringBuilder builder) {
+        builder.append("GROUP_CONCAT(");
         if (distinct) {
-            buff.append("DISTINCT ");
+            builder.append("DISTINCT ");
         }
-        buff.append(on.getSQL());
-        Window.appendOrderBy(buff, orderByList);
+        on.getSQL(builder);
+        Window.appendOrderBy(builder, orderByList);
         if (groupConcatSeparator != null) {
-            buff.append(" SEPARATOR ").append(groupConcatSeparator.getSQL());
+            builder.append(" SEPARATOR ");
+            groupConcatSeparator.getSQL(builder);
         }
-        buff.append(')');
-        return appendTailConditions(buff).toString();
+        builder.append(')');
+        return appendTailConditions(builder);
     }
 
-    private String getSQLArrayAggregate() {
-        StringBuilder buff = new StringBuilder("ARRAY_AGG(");
+    private StringBuilder getSQLArrayAggregate(StringBuilder builder) {
+        builder.append("ARRAY_AGG(");
         if (distinct) {
-            buff.append("DISTINCT ");
+            builder.append("DISTINCT ");
         }
-        buff.append(on.getSQL());
-        Window.appendOrderBy(buff, orderByList);
-        buff.append(')');
-        return appendTailConditions(buff).toString();
+        on.getSQL(builder);
+        Window.appendOrderBy(builder, orderByList);
+        builder.append(')');
+        return appendTailConditions(builder);
     }
 
     @Override
-    public String getSQL() {
+    public StringBuilder getSQL(StringBuilder builder) {
         String text;
         switch (type) {
         case GROUP_CONCAT:
-            return getSQLGroupConcat();
+            return getSQLGroupConcat(builder);
         case COUNT_ALL:
-            return appendTailConditions(new StringBuilder().append("COUNT(*)")).toString();
+            return appendTailConditions(builder.append("COUNT(*)"));
         case COUNT:
             text = "COUNT";
             break;
@@ -811,7 +812,7 @@ public class Aggregate extends AbstractAggregate {
             text = "MEDIAN";
             break;
         case ARRAY_AGG:
-            return getSQLArrayAggregate();
+            return getSQLArrayAggregate(builder);
         case MODE:
             text = "MODE";
             break;
@@ -821,13 +822,14 @@ public class Aggregate extends AbstractAggregate {
         default:
             throw DbException.throwInternalError("type=" + type);
         }
-        StringBuilder builder = new StringBuilder().append(text);
+        builder.append(text);
         if (distinct) {
-            builder.append("(DISTINCT ").append(on.getSQL()).append(')');
+            builder.append("(DISTINCT ");
+            on.getSQL(builder).append(')');
         } else {
             builder.append(StringUtils.enclose(on.getSQL()));
         }
-        return appendTailConditions(builder).toString();
+        return appendTailConditions(builder);
     }
 
     private Index getMinMaxColumnIndex() {

h2/src/main/org/h2/expression/aggregate/JavaAggregate.java

@@ -17,7 +17,6 @@ import org.h2.expression.ExpressionVisitor;
 import org.h2.message.DbException;
 import org.h2.table.ColumnResolver;
 import org.h2.table.TableFilter;
-import org.h2.util.StatementBuilder;
 import org.h2.value.DataType;
 import org.h2.value.Value;
 import org.h2.value.ValueArray;
@@ -68,15 +67,16 @@ public class JavaAggregate extends AbstractAggregate {
     }
 
     @Override
-    public String getSQL() {
-        StatementBuilder buff = new StatementBuilder();
-        buff.append(Parser.quoteIdentifier(userAggregate.getName())).append('(');
-        for (Expression e : args) {
-            buff.appendExceptFirst(", ");
-            buff.append(e.getSQL());
+    public StringBuilder getSQL(StringBuilder builder) {
+        builder.append(Parser.quoteIdentifier(userAggregate.getName())).append('(');
+        for (int i = 0; i < args.length; i++) {
+            if (i > 0) {
+                builder.append(", ");
+            }
+            args[i].getSQL(builder);
         }
-        buff.append(')');
-        return appendTailConditions(buff.builder()).toString();
+        builder.append(')');
+        return appendTailConditions(builder);
     }
 
     @Override

h2/src/main/org/h2/expression/aggregate/Window.java

@@ -49,7 +49,7 @@ public final class Window {
                 if (i > 0) {
                     builder.append(", ");
                 }
-                builder.append(o.expression.getSQL());
+                o.expression.getSQL(builder);
                 SortOrder.typeToString(builder, o.sortType);
             }
         }

h2/src/main/org/h2/expression/aggregate/WindowFrameBound.java

@@ -62,7 +62,8 @@ public class WindowFrameBound {
      */
     public String getSQL(boolean following) {
         if (type == WindowFrameBoundType.PRECEDING || type == WindowFrameBoundType.FOLLOWING) {
-            return value.getSQL() + ' ' + type.getSQL();
+            StringBuilder builder = new StringBuilder();
+            return value.getSQL(builder).append(' ').append(type.getSQL()).toString();
         }
         return type.getSQL();
     }

h2/src/main/org/h2/expression/aggregate/WindowFunction.java

@@ -515,15 +515,15 @@ public class WindowFunction extends DataAnalysisOperation {
     }
 
     @Override
-    public String getSQL() {
+    public StringBuilder getSQL(StringBuilder builder) {
         String name = type.getSQL();
-        StringBuilder builder = new StringBuilder().append(name).append('(');
+        builder.append(name).append('(');
         if (args != null) {
             for (int i = 0, numArgs = args.length; i < numArgs; i++) {
                 if (i > 0) {
                     builder.append(", ");
                 }
-                builder.append(args[i].getSQL());
+                args[i].getSQL(builder);
             }
         }
         builder.append(')');
@@ -542,7 +542,7 @@ public class WindowFunction extends DataAnalysisOperation {
             default:
             }
         }
-        return appendTailConditions(builder).toString();
+        return appendTailConditions(builder);
     }
 
     @Override

h2/src/main/org/h2/index/IndexCondition.java

@@ -202,7 +202,7 @@ public class IndexCondition {
             buff.append(" IN(");
             for (Expression e : expressionList) {
                 buff.appendExceptFirst(", ");
-                buff.append(e.getSQL());
+                e.getSQL(buff.builder());
             }
             buff.append(')');
             break;
@@ -218,7 +218,7 @@ public class IndexCondition {
             DbException.throwInternalError("type=" + compareType);
         }
         if (expression != null) {
-            buff.append(expression.getSQL());
+            expression.getSQL(buff.builder());
         }
         return buff.toString();
     }

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

@@ -72,11 +72,15 @@ public class RangeTable extends Table {
 
     @Override
     public String getSQL() {
-        String sql = NAME + "(" + min.getSQL() + ", " + max.getSQL();
+        StringBuilder builder = new StringBuilder();
+        builder.append(NAME).append('(');
+        min.getSQL(builder).append(", ");
+        max.getSQL(builder);
         if (step != null) {
-            sql += ", " + step.getSQL();
+            builder.append(", ");
+            step.getSQL(builder);
         }
-        return sql + ")";
+        return builder.append(')').toString();
     }
 
     @Override