SQLASTOutputVisitor.java

/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2012 All Rights Reserved.
 */
package com.alipay.zdal.parser.sql.visitor;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.alipay.zdal.parser.exceptions.SqlParserException;
import com.alipay.zdal.parser.sql.ast.SQLCommentHint;
import com.alipay.zdal.parser.sql.ast.SQLDataType;
import com.alipay.zdal.parser.sql.ast.SQLExpr;
import com.alipay.zdal.parser.sql.ast.SQLObject;
import com.alipay.zdal.parser.sql.ast.SQLOrderBy;
import com.alipay.zdal.parser.sql.ast.SQLSetQuantifier;
import com.alipay.zdal.parser.sql.ast.SQLStatement;
import com.alipay.zdal.parser.sql.ast.expr.SQLAggregateExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLAllColumnExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLAllExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLAnyExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLBetweenExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLBinaryOpExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLBinaryOperator;
import com.alipay.zdal.parser.sql.ast.expr.SQLCaseExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLCastExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLCharExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLCurrentOfCursorExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLDefaultExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLExistsExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLHexExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLIdentifierExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLInListExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLInSubQueryExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLIntegerExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLListExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLMethodInvokeExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLNCharExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLNotExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLNullExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLNumberExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLObjectCreateExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLPropertyExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLQueryExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLSomeExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLUnaryExpr;
import com.alipay.zdal.parser.sql.ast.expr.SQLVariantRefExpr;
import com.alipay.zdal.parser.sql.ast.statement.NotNullConstraint;
import com.alipay.zdal.parser.sql.ast.statement.SQLAlterTableAddColumn;
import com.alipay.zdal.parser.sql.ast.statement.SQLAlterTableDropColumnItem;
import com.alipay.zdal.parser.sql.ast.statement.SQLAssignItem;
import com.alipay.zdal.parser.sql.ast.statement.SQLCallStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLColumnConstraint;
import com.alipay.zdal.parser.sql.ast.statement.SQLColumnDefinition;
import com.alipay.zdal.parser.sql.ast.statement.SQLCommentStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLCreateDatabaseStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLCreateTableStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLDeleteStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLDropIndexStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLDropTableStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLDropViewStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLExprTableSource;
import com.alipay.zdal.parser.sql.ast.statement.SQLInsertStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLInsertStatement.ValuesClause;
import com.alipay.zdal.parser.sql.ast.statement.SQLJoinTableSource;
import com.alipay.zdal.parser.sql.ast.statement.SQLJoinTableSource.JoinType;
import com.alipay.zdal.parser.sql.ast.statement.SQLReleaseSavePointStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLRollbackStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLSavePointStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelect;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelectGroupByClause;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelectItem;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelectOrderByItem;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelectQueryBlock;
import com.alipay.zdal.parser.sql.ast.statement.SQLSelectStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLSetStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLSubqueryTableSource;
import com.alipay.zdal.parser.sql.ast.statement.SQLTableElement;
import com.alipay.zdal.parser.sql.ast.statement.SQLTruncateStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLUnionQuery;
import com.alipay.zdal.parser.sql.ast.statement.SQLUniqueConstraint;
import com.alipay.zdal.parser.sql.ast.statement.SQLUpdateSetItem;
import com.alipay.zdal.parser.sql.ast.statement.SQLUpdateStatement;
import com.alipay.zdal.parser.sql.ast.statement.SQLUseStatement;

/**
 * 
 * @author ����
 * @version $Id: SQLASTOutputVisitor.java, v 0.1 2012-11-17 ����3:56:21 Exp $
 */
public class SQLASTOutputVisitor extends SQLASTVisitorAdapter {

    protected final Appendable appender;
    private String             indent      = "\t";
    private int                indentCount = 0;

    public SQLASTOutputVisitor(Appendable appender) {
        this.appender = appender;
    }

    public int getIndentCount() {
        return indentCount;
    }

    public Appendable getAppender() {
        return appender;
    }

    public void decrementIndent() {
        this.indentCount -= 1;
    }

    public void incrementIndent() {
        this.indentCount += 1;
    }

    public void print(char value) {
        try {
            this.appender.append(value);
        } catch (IOException e) {
            throw new SqlParserException("println error", e);
        }
    }

    public void print(int value) {
        print(Integer.toString(value));
    }

    public void print(long value) {
        print(Long.toString(value));
    }

    public void print(String text) {
        try {
            this.appender.append(text);
        } catch (IOException e) {
            throw new SqlParserException("println error", e);
        }
    }

    protected void printAlias(String alias) {
        if ((alias != null) && (alias.length() > 0)) {
            print(" ");
            print(alias);
        }
    }

    protected void printAndAccept(List<? extends SQLObject> nodes, String seperator) {
        for (int i = 0, size = nodes.size(); i < size; ++i) {
            if (i != 0) {
                print(seperator);
            }
            nodes.get(i).accept(this);
        }
    }

    protected void printSelectList(List<SQLSelectItem> selectList) {
        incrementIndent();
        for (int i = 0, size = selectList.size(); i < size; ++i) {
            if (i != 0) {
                if (i % 5 == 0) {
                    println();
                }

                print(", ");
            }

            selectList.get(i).accept(this);
        }
        decrementIndent();
    }

    protected void printlnAndAccept(List<? extends SQLObject> nodes, String seperator) {
        for (int i = 0, size = nodes.size(); i < size; ++i) {
            if (i != 0) {
                println(seperator);
            }

            ((SQLObject) nodes.get(i)).accept(this);
        }
    }

    public void printIndent() {
        for (int i = 0; i < this.indentCount; ++i)
            print(this.indent);
    }

    public void println() {
        print("\n");
        printIndent();
    }

    public void println(String text) {
        print(text);
        println();
    }

    // ////////////////////

    public boolean visit(SQLBetweenExpr x) {
        x.getTestExpr().accept(this);

        if (x.isNot()) {
            print(" NOT BETWEEN ");
        } else {
            print(" BETWEEN ");
        }

        x.getBeginExpr().accept(this);
        print(" AND ");
        x.getEndExpr().accept(this);

        return false;
    }

    public boolean visit(SQLBinaryOpExpr x) {
        SQLObject parent = x.getParent();
        boolean isRoot = parent instanceof SQLSelectQueryBlock;
        boolean relational = x.getOperator() == SQLBinaryOperator.BooleanAnd
                             || x.getOperator() == SQLBinaryOperator.BooleanOr;

        if (isRoot && relational) {
            incrementIndent();
        }

        List<SQLExpr> groupList = new ArrayList<SQLExpr>();
        SQLExpr left = x.getLeft();
        for (;;) {
            if (left instanceof SQLBinaryOpExpr
                && ((SQLBinaryOpExpr) left).getOperator() == x.getOperator()) {
                SQLBinaryOpExpr binaryLeft = (SQLBinaryOpExpr) left;
                groupList.add(binaryLeft.getRight());
                left = binaryLeft.getLeft();
            } else {
                groupList.add(left);
                break;
            }
        }

        for (int i = groupList.size() - 1; i >= 0; --i) {
            SQLExpr item = groupList.get(i);
            visitBinaryLeft(item, x.getOperator());

            if (relational) {
                println();
            } else {
                print(" ");
            }
            print(x.getOperator().name);
            print(" ");
        }

        visitorBinaryRight(x);

        if (isRoot && relational) {
            decrementIndent();
        }

        return false;
    }

    private void visitorBinaryRight(SQLBinaryOpExpr x) {
        if (x.getRight() instanceof SQLBinaryOpExpr) {
            SQLBinaryOpExpr right = (SQLBinaryOpExpr) x.getRight();
            boolean rightRational = right.getOperator() == SQLBinaryOperator.BooleanAnd
                                    || right.getOperator() == SQLBinaryOperator.BooleanOr;

            if (right.getOperator().priority >= x.getOperator().priority) {
                if (rightRational) {
                    incrementIndent();
                }

                print('(');
                right.accept(this);
                print(')');

                if (rightRational) {
                    decrementIndent();
                }
            } else {
                right.accept(this);
            }
        } else {
            x.getRight().accept(this);
        }
    }

    private void visitBinaryLeft(SQLExpr left, SQLBinaryOperator op) {
        if (left instanceof SQLBinaryOpExpr) {
            SQLBinaryOpExpr binaryLeft = (SQLBinaryOpExpr) left;
            boolean leftRational = binaryLeft.getOperator() == SQLBinaryOperator.BooleanAnd
                                   || binaryLeft.getOperator() == SQLBinaryOperator.BooleanOr;

            if (binaryLeft.getOperator().priority > op.priority) {
                if (leftRational) {
                    incrementIndent();
                }
                print('(');
                left.accept(this);
                print(')');

                if (leftRational) {
                    decrementIndent();
                }
            } else {
                left.accept(this);
            }
        } else {
            left.accept(this);
        }
    }

    public boolean visit(SQLCaseExpr x) {
        print("CASE ");
        if (x.getValueExpr() != null) {
            x.getValueExpr().accept(this);
            print(" ");
        }

        printAndAccept(x.getItems(), " ");

        if (x.getElseExpr() != null) {
            print(" ELSE ");
            x.getElseExpr().accept(this);
        }

        print(" END");
        return false;
    }

    public boolean visit(SQLCaseExpr.Item x) {
        print("WHEN ");
        x.getConditionExpr().accept(this);
        print(" THEN ");
        x.getValueExpr().accept(this);
        return false;
    }

    public boolean visit(SQLCastExpr x) {
        print("CAST(");
        x.getExpr().accept(this);
        print(" AS ");
        x.getDataType().accept(this);
        print(")");

        return false;
    }

    public boolean visit(SQLCharExpr x) {
        if ((x.getText() == null) || (x.getText().length() == 0)) {
            print("NULL");
        } else {
            print("'");
            print(x.getText().replaceAll("'", "''"));
            print("'");
        }

        return false;
    }

    public boolean visit(SQLDataType x) {
        print(x.getName());
        if (x.getArguments().size() > 0) {
            print("(");
            printAndAccept(x.getArguments(), ", ");
            print(")");
        }

        return false;
    }

    public boolean visit(SQLExistsExpr x) {
        if (x.isNot())
            print("NOT EXISTS (");
        else {
            print("EXISTS (");
        }
        incrementIndent();
        x.getSubQuery().accept(this);
        decrementIndent();
        print(")");
        return false;
    }

    public boolean visit(SQLIdentifierExpr astNode) {
        print(astNode.getName());
        return false;
    }

    public boolean visit(SQLInListExpr x) {
        x.getExpr().accept(this);

        if (x.isNot()) {
            print(" NOT IN (");
        } else {
            print(" IN (");
        }

        printAndAccept(x.getTargetList(), ", ");
        print(')');
        return false;
    }

    public boolean visit(SQLIntegerExpr x) {
        print(x.getNumber().toString());
        return false;
    }

    public boolean visit(SQLMethodInvokeExpr x) {
        if (x.getOwner() != null) {
            x.getOwner().accept(this);
            print(".");
        }
        print(x.getMethodName());
        print("(");
        printAndAccept(x.getParameters(), ", ");
        print(")");
        return false;
    }

    public boolean visit(SQLAggregateExpr x) {
        print(x.getMethodName());
        print("(");

        if (x.getOption() != null) {
            print(x.getOption().toString());
            print(' ');
        }

        printAndAccept(x.getArguments(), ", ");
        print(")");
        return false;
    }

    public boolean visit(SQLAllColumnExpr x) {
        print("*");
        return true;
    }

    public boolean visit(SQLNCharExpr x) {
        if ((x.getText() == null) || (x.getText().length() == 0)) {
            print("NULL");
        } else {
            print("N'");
            print(x.getText().replace("'", "''"));
            print("'");
        }
        return false;
    }

    public boolean visit(SQLNotExpr x) {
        print("NOT ");
        x.getExpr().accept(this);
        return false;
    }

    public boolean visit(SQLNullExpr x) {
        print("NULL");
        return false;
    }

    public boolean visit(SQLNumberExpr x) {
        print(x.getNumber().toString());
        return false;
    }

    public boolean visit(SQLObjectCreateExpr x) {
        throw new UnsupportedOperationException();
    }

    public boolean visit(SQLPropertyExpr x) {
        x.getOwner().accept(this);
        print(".");
        print(x.getName());
        return false;
    }

    public boolean visit(SQLQueryExpr x) {
        SQLObject parent = x.getParent();
        if (parent instanceof SQLSelect) {
            parent = parent.getParent();
        }

        if (parent instanceof SQLStatement) {
            incrementIndent();

            println();
            x.getSubQuery().accept(this);

            decrementIndent();
        } else if (parent instanceof ValuesClause) {
            println();
            x.getSubQuery().accept(this);
            println();
        } else {
            print("(");
            incrementIndent();
            println();
            x.getSubQuery().accept(this);
            println();
            decrementIndent();
            print(")");
        }
        return false;
    }

    public boolean visit(SQLSelectGroupByClause x) {
        if (x.getItems().size() > 0) {
            print("GROUP BY ");
            printAndAccept(x.getItems(), ", ");
        }

        if (x.getHaving() != null) {
            println();
            print("HAVING ");
            x.getHaving().accept(this);
        }
        return false;
    }

    public boolean visit(SQLSelect x) {
        x.getQuery().setParent(x);
        x.getQuery().accept(this);

        if (x.getOrderBy() != null) {
            println();
            x.getOrderBy().accept(this);
        }

        return false;
    }

    public boolean visit(SQLSelectQueryBlock x) {
        print("SELECT ");

        if (SQLSetQuantifier.ALL == x.getDistionOption()) {
            print("ALL ");
        } else if (SQLSetQuantifier.DISTINCT == x.getDistionOption()) {
            print("DISTINCT ");
        } else if (SQLSetQuantifier.UNIQUE == x.getDistionOption()) {
            print("UNIQUE ");
        }

        printSelectList(x.getSelectList());

        if (x.getFrom() != null) {
            println();
            print("FROM ");
            x.getFrom().accept(this);
        }

        if (x.getWhere() != null) {
            println();
            print("WHERE ");
            x.getWhere().setParent(x);
            x.getWhere().accept(this);
        }

        if (x.getGroupBy() != null) {
            print(" ");
            x.getGroupBy().accept(this);
        }

        return false;
    }

    public boolean visit(SQLSelectItem x) {
        x.getExpr().accept(this);

        if ((x.getAlias() != null) && (x.getAlias().length() > 0)) {
            print(" AS ");
            print(x.getAlias());
        }
        return false;
    }

    public boolean visit(SQLOrderBy x) {
        if (x.getItems().size() > 0) {
            print("ORDER BY ");

            printAndAccept(x.getItems(), ", ");
        }
        return false;
    }

    public boolean visit(SQLSelectOrderByItem x) {
        x.getExpr().accept(this);
        if (x.getType() != null) {
            print(" ");
            print(x.getType().name().toUpperCase());
        }

        if (x.getCollate() != null) {
            print(" COLLATE ");
            print(x.getCollate());
        }

        return false;
    }

    public boolean visit(SQLExprTableSource x) {
        x.getExpr().accept(this);

        if (x.getAlias() != null) {
            print(' ');
            print(x.getAlias());
        }

        return false;
    }

    public boolean visit(SQLSelectStatement stmt) {
        SQLSelect select = stmt.getSelect();

        select.accept(this);

        return false;
    }

    public boolean visit(SQLVariantRefExpr x) {
        print(x.getName());
        return false;
    }

    public boolean visit(SQLDropTableStatement x) {
        print("DROP TABLE ");
        printAndAccept(x.getTableSources(), ", ");
        return false;
    }

    public boolean visit(SQLDropViewStatement x) {
        print("DROP VIEW ");
        printAndAccept(x.getTableSources(), ", ");
        return false;
    }

    public boolean visit(SQLTableElement x) {
        if (x instanceof SQLColumnDefinition) {
            return visit((SQLColumnDefinition) x);
        }

        throw new SqlParserException("TODO");
    }

    public boolean visit(SQLColumnDefinition x) {
        x.getName().accept(this);

        if (x.getDataType() != null) {
            print(' ');
            x.getDataType().accept(this);
        }

        if (x.getDefaultExpr() != null) {
            visitColumnDefault(x);
        }

        for (SQLColumnConstraint item : x.getConstaints()) {
            print(' ');
            item.accept(this);
        }

        if (x.getEnable() != null) {
            if (x.getEnable().booleanValue()) {
                print(" ENABLE");
            }
        }

        return false;
    }

    protected void visitColumnDefault(SQLColumnDefinition x) {
        print(" DEFAULT ");
        x.getDefaultExpr().accept(this);
    }

    public boolean visit(SQLDeleteStatement x) {
        print("DELETE FROM ");

        x.getTableName().accept(this);

        if (x.getWhere() != null) {
            print(" WHERE ");
            x.getWhere().setParent(x);
            x.getWhere().accept(this);
        }

        return false;
    }

    public boolean visit(SQLCurrentOfCursorExpr x) {
        print("CURRENT OF ");
        x.getCursorName().accept(this);
        return false;
    }

    public boolean visit(SQLInsertStatement x) {
        print("INSERT INTO ");

        x.getTableName().accept(this);

        if (x.getColumns().size() > 0) {
            incrementIndent();
            println();
            print("(");
            for (int i = 0, size = x.getColumns().size(); i < size; ++i) {
                if (i != 0) {
                    if (i % 5 == 0) {
                        println();
                    }
                    print(", ");
                }
                x.getColumns().get(i).accept(this);
            }
            print(")");
            decrementIndent();
        }

        if (x.getValues() != null) {
            println();
            print("VALUES");
            println();
            x.getValues().accept(this);
        } else {
            if (x.getQuery() != null) {
                println();
                x.getQuery().setParent(x);
                x.getQuery().accept(this);
            }
        }

        return false;
    }

    public boolean visit(SQLUpdateSetItem x) {
        x.getColumn().accept(this);
        print(" = ");
        x.getValue().accept(this);
        return false;
    }

    public boolean visit(SQLUpdateStatement x) {
        print("UPDATE ");

        x.getTableSource().accept(this);

        println();
        print("SET ");
        for (int i = 0, size = x.getItems().size(); i < size; ++i) {
            if (i != 0) {
                print(", ");
            }
            x.getItems().get(i).accept(this);
        }

        if (x.getWhere() != null) {
            println();
            print("WHERE ");
            x.getWhere().setParent(x);
            x.getWhere().accept(this);
        }

        return false;
    }

    public boolean visit(SQLCreateTableStatement x) {
        print("CREATE TABLE ");
        if (SQLCreateTableStatement.Type.GLOBAL_TEMPORARY.equals(x.getType())) {
            print("GLOBAL TEMPORARY ");
        } else if (SQLCreateTableStatement.Type.LOCAL_TEMPORARY.equals(x.getType())) {
            print("LOCAL TEMPORARY ");
        }

        x.getName().accept(this);

        int size = x.getTableElementList().size();

        if (size > 0) {
            print(" (");
            incrementIndent();
            println();
            for (int i = 0; i < size; ++i) {
                if (i != 0) {
                    print(", ");
                    println();
                }
                x.getTableElementList().get(i).accept(this);
            }
            decrementIndent();
            println();
            print(")");
        }

        return false;
    }

    public boolean visit(SQLUniqueConstraint x) {
        if (x.getName() != null) {
            print("CONSTRAINT ");
            x.getName().accept(this);
            print(' ');
        }

        print("UNIQUE (");
        for (int i = 0, size = x.getColumns().size(); i < size; ++i) {
            if (i != 0) {
                print(", ");
            }
            x.getColumns().get(i).accept(this);
        }
        print(")");
        return false;
    }

    public boolean visit(NotNullConstraint x) {
        print("NOT NULL");
        return false;
    }

    @Override
    public boolean visit(SQLUnionQuery x) {
        x.getLeft().accept(this);
        println();
        print(x.getOperator().name);
        println();

        boolean needParen = false;

        if (x.getOrderBy() != null) {
            needParen = true;
        }

        if (needParen) {
            print('(');
            x.getRight().accept(this);
            print(')');
        } else {
            x.getRight().accept(this);
        }

        if (x.getOrderBy() != null) {
            println();
            x.getOrderBy().accept(this);
        }

        return false;
    }

    @Override
    public boolean visit(SQLUnaryExpr x) {
        print(x.getOperator().name);
        SQLExpr expr = x.getExpr();
        if (expr instanceof SQLBinaryOpExpr) {
            print('(');
            expr.accept(this);
            print(')');
        } else if (expr instanceof SQLUnaryExpr) {
            print('(');
            expr.accept(this);
            print(')');
        } else {
            expr.accept(this);
        }
        return false;
    }

    @Override
    public boolean visit(SQLHexExpr x) {
        print("0x");
        print(x.getHex());

        String charset = (String) x.getAttribute("USING");
        if (charset != null) {
            print(" USING ");
            print(charset);
        }

        return false;
    }

    @Override
    public boolean visit(SQLSetStatement x) {
        print("SET ");
        printAndAccept(x.getItems(), ", ");
        return false;
    }

    @Override
    public boolean visit(SQLAssignItem x) {
        x.getTarget().accept(this);
        print(" = ");
        x.getValue().accept(this);
        return false;
    }

    @Override
    public boolean visit(SQLCallStatement x) {
        print("CALL ");
        x.getProcedureName().accept(this);
        print('(');
        printAndAccept(x.getParameters(), ", ");
        print(')');
        return false;
    }

    @Override
    public boolean visit(SQLJoinTableSource x) {
        x.getLeft().accept(this);
        if (x.getJoinType() == JoinType.COMMA) {
            print(",");
        } else {
            print(" ");
            print(JoinType.toString(x.getJoinType()));
        }
        print(" ");
        x.getRight().accept(this);

        if (x.getCondition() != null) {
            print(" ON ");
            x.getCondition().accept(this);
        }

        return false;
    }

    @Override
    public boolean visit(ValuesClause x) {
        print("(");
        incrementIndent();
        for (int i = 0, size = x.getValues().size(); i < size; ++i) {
            if (i != 0) {
                if (i % 5 == 0) {
                    println();
                }
                print(", ");
            }

            SQLExpr expr = x.getValues().get(i);
            expr.setParent(x);
            expr.accept(this);
        }
        decrementIndent();
        print(")");
        return false;
    }

    @Override
    public boolean visit(SQLSomeExpr x) {
        print("SOME (");

        incrementIndent();
        x.getSubQuery().accept(this);
        decrementIndent();
        print(")");
        return false;
    }

    @Override
    public boolean visit(SQLAnyExpr x) {
        print("ANY (");

        incrementIndent();
        x.getSubQuery().accept(this);
        decrementIndent();
        print(")");
        return false;
    }

    @Override
    public boolean visit(SQLAllExpr x) {
        print("ALL (");

        incrementIndent();
        x.getSubQuery().accept(this);
        decrementIndent();
        print(")");
        return false;
    }

    @Override
    public boolean visit(SQLInSubQueryExpr x) {
        x.getExpr().accept(this);
        if (x.isNot()) {
            print(" NOT IN (");
        } else {
            print(" IN (");
        }

        incrementIndent();
        x.getSubQuery().accept(this);
        decrementIndent();
        print(")");

        return false;
    }

    @Override
    public boolean visit(SQLListExpr x) {
        print("(");
        printAndAccept(x.getItems(), ", ");
        print(")");

        return false;
    }

    @Override
    public boolean visit(SQLSubqueryTableSource x) {
        print("(");
        incrementIndent();
        x.getSelect().accept(this);
        println();
        decrementIndent();
        print(")");

        if (x.getAlias() != null) {
            print(' ');
            print(x.getAlias());
        }

        return false;
    }

    @Override
    public boolean visit(SQLTruncateStatement x) {
        print("TRUNCATE TABLE ");
        printAndAccept(x.getTableSources(), ", ");
        return false;
    }

    @Override
    public boolean visit(SQLDefaultExpr x) {
        print("DEFAULT");
        return false;
    }

    @Override
    public void endVisit(SQLCommentStatement x) {

    }

    @Override
    public boolean visit(SQLCommentStatement x) {
        print("COMMENT ON ");
        if (x.getType() != null) {
            print(x.getType().name());
            print(" ");
        }
        x.getOn().accept(this);

        print(" IS ");
        x.getComment().accept(this);

        return false;
    }

    @Override
    public boolean visit(SQLUseStatement x) {
        print("USE ");
        x.getDatabase().accept(this);
        return false;
    }

    @Override
    public boolean visit(SQLAlterTableAddColumn x) {
        print("ADD (");
        printAndAccept(x.getColumns(), ", ");
        print(")");
        return false;
    }

    @Override
    public boolean visit(SQLAlterTableDropColumnItem x) {
        print("DROP COLUMN ");
        x.getColumnName().accept(this);
        return false;
    }

    @Override
    public void endVisit(SQLAlterTableAddColumn x) {

    }

    @Override
    public boolean visit(SQLDropIndexStatement x) {
        print("DROP INDEX ");
        x.getIndexName().accept(this);
        print(" ON ");
        x.getTableName().accept(this);
        return false;
    }

    @Override
    public boolean visit(SQLSavePointStatement x) {
        print("SAVEPOINT ");
        x.getName().accept(this);
        return false;
    }

    @Override
    public boolean visit(SQLReleaseSavePointStatement x) {
        print("RELEASE SAVEPOINT ");
        x.getName().accept(this);
        return false;
    }

    @Override
    public boolean visit(SQLRollbackStatement x) {
        print("ROLLBACK");
        if (x.getTo() != null) {
            print(" TO ");
            x.getTo().accept(this);
        }
        return false;
    }

    public boolean visit(SQLCommentHint x) {
        print("/*");
        print(x.getText());
        print("*/");
        return false;
    }

    @Override
    public boolean visit(SQLCreateDatabaseStatement x) {
        print("CREATE DATABASE ");
        x.getName().accept(this);
        return false;
    }
}