column.java

非常棒的java数据库

    }

    /**
     * Convert the auto-increment flag to a sequence that is linked with this
     * table.
     * 
     * @param session the session
     * @param schema the schema where the sequence should be generated
     * @param id the object id
     * @param temporary true if the sequence is temporary and does not need to
     *            be stored
     */
    public void convertAutoIncrementToSequence(Session session, Schema schema, int id, boolean temporary)
            throws SQLException {
        if (!autoIncrement) {
            throw Message.getInternalError();
        }
        if ("IDENTITY".equals(originalSQL)) {
            originalSQL = "BIGINT";
        }
        String sequenceName;
        for (int i = 0;; i++) {
            ValueUuid uuid = ValueUuid.getNewRandom();
            String s = uuid.getString();
            s = s.replace('-', '_').toUpperCase();
            sequenceName = "SYSTEM_SEQUENCE_" + s;
            if (schema.findSequence(sequenceName) == null) {
                break;
            }
        }
        Sequence sequence = new Sequence(schema, id, sequenceName, true);
        sequence.setStartValue(start);
        sequence.setIncrement(increment);
        if (!temporary) {
            session.getDatabase().addSchemaObject(session, sequence);
        }
        setAutoIncrement(false, 0, 0);
        SequenceValue seq = new SequenceValue(sequence);
        setDefaultExpression(session, seq);
        setSequence(sequence);
    }

    public void prepareExpression(Session session) throws SQLException {
        if (defaultExpression != null) {
            computeTableFilter = new TableFilter(session, table, null, false, null);
            defaultExpression.mapColumns(computeTableFilter, 0);
            defaultExpression = defaultExpression.optimize(session);
        }
    }

    public String getCreateSQL() {
        StringBuffer buff = new StringBuffer();
        if (name != null) {
            buff.append(Parser.quoteIdentifier(name));
            buff.append(' ');
        }
        if (originalSQL != null) {
            buff.append(originalSQL);
        } else {
            buff.append(DataType.getDataType(type).name);
            switch (type) {
            case Value.DECIMAL:
                buff.append("(");
                buff.append(precision);
                buff.append(", ");
                buff.append(scale);
                buff.append(")");
                break;
            case Value.BYTES:
            case Value.STRING:
            case Value.STRING_IGNORECASE:
            case Value.STRING_FIXED:
                if (precision < Integer.MAX_VALUE) {
                    buff.append("(");
                    buff.append(precision);
                    buff.append(")");
                }
                break;
            default:
            }
        }
        if (defaultExpression != null) {
            String sql = defaultExpression.getSQL();
            if (sql != null) {
                if (isComputed) {
                    buff.append(" AS ");
                    buff.append(sql);
                } else if (defaultExpression != null) {
                    buff.append(" DEFAULT ");
                    buff.append(sql);
                }
            }
        }
        if (!nullable) {
            buff.append(" NOT NULL");
        }
        if (convertNullToDefault) {
            buff.append(" NULL_TO_DEFAULT");
        }
        if (sequence != null) {
            buff.append(" SEQUENCE ");
            buff.append(sequence.getSQL());
        }
        if (selectivity != 0) {
            buff.append(" SELECTIVITY ");
            buff.append(selectivity);
        }
        if (checkConstraint != null) {
            buff.append(" CHECK ");
            buff.append(checkConstraintSQL);
        }
        if (comment != null) {
            buff.append(" COMMENT ");
            buff.append(StringUtils.quoteStringSQL(comment));
        }
        return buff.toString();
    }

    public boolean getNullable() {
        return nullable;
    }

    public void setOriginalSQL(String original) {
        originalSQL = original;
    }

    public String getOriginalSQL() {
        return originalSQL;
    }

    public Expression getDefaultExpression() {
        return defaultExpression;
    }

    public boolean getAutoIncrement() {
        return autoIncrement;
    }

    public void setAutoIncrement(boolean autoInc, long start, long increment) {
        this.autoIncrement = autoInc;
        this.start = start;
        this.increment = increment;
        this.nullable = false;
        if (autoInc) {
            convertNullToDefault = true;
        }
    }

    public void setConvertNullToDefault(boolean convert) {
        this.convertNullToDefault = convert;
    }

    public void rename(String newName) {
        this.name = newName;
    }

    public void setSequence(Sequence sequence) {
        this.sequence = sequence;
    }

    public Sequence getSequence() {
        return sequence;
    }

    /**
     * Get the selectivity of the column. Selectivity 100 means values are
     * unique, 10 means every distinct value appears 10 times on average.
     * 
     * @return the selectivity
     */
    public int getSelectivity() {
        return selectivity == 0 ? Constants.SELECTIVITY_DEFAULT : selectivity;
    }

    /**
     * Set the new selectivity of a column.
     *
     * @param selectivity the new value
     */
    public void setSelectivity(int selectivity) {
        selectivity = selectivity < 0 ? 0 : (selectivity > 100 ? 100 : selectivity);
        this.selectivity = selectivity;
    }

    public void addCheckConstraint(Session session, Expression expr) throws SQLException {
        resolver = new SingleColumnResolver(this);
        synchronized (this) {
            String oldName = name;
            if (name == null) {
                name = "VALUE";
            }
            expr.mapColumns(resolver, 0);
            name = oldName;
        }
        expr = expr.optimize(session);
        resolver.setValue(ValueNull.INSTANCE);
        // check if the column is mapped
        synchronized (this) {
            expr.getValue(session);
        }
        if (checkConstraint == null) {
            checkConstraint = expr;
        } else {
            checkConstraint = new ConditionAndOr(ConditionAndOr.AND, checkConstraint, expr);
        }
        checkConstraintSQL = getCheckConstraintSQL(session, name);
    }

    public Expression getCheckConstraint(Session session, String asColumnName) throws SQLException {
        if (checkConstraint == null) {
            return null;
        }
        Parser parser = new Parser(session);
        String sql;
        synchronized (this) {
            String oldName = name;
            name = asColumnName;
            sql = checkConstraint.getSQL();
            name = oldName;
        }
        Expression expr = parser.parseExpression(sql);
        return expr;
    }

    public String getDefaultSQL() {
        return defaultExpression == null ? null : defaultExpression.getSQL();
    }

    public int getPrecisionAsInt() {
        return MathUtils.convertLongToInt(precision);
    }

    public DataType getDataType() {
        return DataType.getDataType(type);
    }

    public String getCheckConstraintSQL(Session session, String name) throws SQLException {
        Expression constraint = getCheckConstraint(session, name);
        return constraint == null ? "" : constraint.getSQL();
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    public String getComment() {
        return comment;
    }

    public void setPrimaryKey(boolean primaryKey) {
        this.primaryKey = primaryKey;
    }

    boolean isEverything(ExpressionVisitor visitor) {
        if (visitor.type == ExpressionVisitor.GET_DEPENDENCIES) {
            if (sequence != null) {
                visitor.getDependencies().add(sequence);
            }
        }
        if (defaultExpression != null && !defaultExpression.isEverything(visitor)) {
            return false;
        }
        if (checkConstraint != null && !checkConstraint.isEverything(visitor)) {
            return false;
        }
        return true;
    }

}